Release/td 5493 (#6993)

* merge jdbc update on develop into master

* remove useless test cases

* change

* change

* remove uneccesary test case

* change

src/connector/jdbc/CMakeLists.txt

@@ -8,7 +8,7 @@ IF (TD_MVN_INSTALLED)
   ADD_CUSTOM_COMMAND(OUTPUT ${JDBC_CMD_NAME}
     POST_BUILD
     COMMAND mvn -Dmaven.test.skip=true install -f ${CMAKE_CURRENT_SOURCE_DIR}/pom.xml
-    COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/target/taos-jdbcdriver-2.0.31.jar ${LIBRARY_OUTPUT_PATH}
+    COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/target/taos-jdbcdriver-2.0.33.jar ${LIBRARY_OUTPUT_PATH}
     COMMAND mvn -Dmaven.test.skip=true clean -f ${CMAKE_CURRENT_SOURCE_DIR}/pom.xml
     COMMENT "build jdbc driver")
   ADD_CUSTOM_TARGET(${JDBC_TARGET_NAME} ALL WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH} DEPENDS ${JDBC_CMD_NAME})

src/connector/jdbc/deploy-pom.xml

@@ -5,7 +5,7 @@
 
   <groupId>com.taosdata.jdbc</groupId>
   <artifactId>taos-jdbcdriver</artifactId>
-  <version>2.0.31</version>
+  <version>2.0.33</version>
   <packaging>jar</packaging>
 
   <name>JDBCDriver</name>

src/connector/jdbc/pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.taosdata.jdbc</groupId>
     <artifactId>taos-jdbcdriver</artifactId>
-    <version>2.0.31</version>
+    <version>2.0.33</version>
     <packaging>jar</packaging>
     <name>JDBCDriver</name>
     <url>https://github.com/taosdata/TDengine/tree/master/src/connector/jdbc</url>
@@ -37,27 +37,26 @@
         <maven.test.jvmargs></maven.test.jvmargs>
     </properties>
     <dependencies>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>4.13</version>
-            <scope>test</scope>
-        </dependency>
-        <!-- for restful -->
         <dependency>
             <groupId>org.apache.httpcomponents</groupId>
             <artifactId>httpclient</artifactId>
-            <version>4.5.8</version>
+            <version>4.5.13</version>
         </dependency>
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>fastjson</artifactId>
-            <version>1.2.58</version>
+            <version>1.2.76</version>
         </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>29.0-jre</version>
+            <version>30.1.1-jre</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.1</version>
+            <scope>test</scope>
         </dependency>
     </dependencies>
 
@@ -113,17 +112,19 @@
                         <include>**/*Test.java</include>
                     </includes>
                     <excludes>
-                        <exclude>**/TSDBJNIConnectorTest.java</exclude>
-                        <exclude>**/UnsignedNumberJniTest.java</exclude>
-                        <exclude>**/DatetimeBefore1970Test.java</exclude>
+                        <exclude>**/TimestampPrecisionInNanoInJniTest.java</exclude>
+                        <exclude>**/NanoSecondTimestampJNITest.java</exclude>
+                        <exclude>**/NanoSecondTimestampRestfulTest.java</exclude>
                         <exclude>**/AppMemoryLeakTest.java</exclude>
                         <exclude>**/AuthenticationTest.java</exclude>
-                        <exclude>**/TaosInfoMonitorTest.java</exclude>
+                        <exclude>**/ConnectMultiTaosdByRestfulWithDifferentTokenTest.java</exclude>
+                        <exclude>**/DatetimeBefore1970Test.java</exclude>
                         <exclude>**/FailOverTest.java</exclude>
                         <exclude>**/InvalidResultSetPointerTest.java</exclude>
                         <exclude>**/RestfulConnectionTest.java</exclude>
-                        <exclude>**/TD4144Test.java</exclude>
-                        <exclude>**/ConnectMultiTaosdByRestfulWithDifferentTokenTest.java</exclude>
+                        <exclude>**/TSDBJNIConnectorTest.java</exclude>
+                        <exclude>**/TaosInfoMonitorTest.java</exclude>
+                        <exclude>**/UnsignedNumberJniTest.java</exclude>
                     </excludes>
                     <testFailureIgnore>true</testFailureIgnore>
                 </configuration>

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractConnection.java

 package com.taosdata.jdbc;
 
+import com.taosdata.jdbc.enums.TimestampFormat;
+
 import java.sql.*;
 import java.util.Enumeration;
 import java.util.Map;
@@ -18,7 +20,7 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
         for (String propName : propNames) {
             clientInfoProps.setProperty(propName, properties.getProperty(propName));
         }
-        String timestampFormat = properties.getProperty(TSDBDriver.PROPERTY_KEY_TIMESTAMP_FORMAT, "STRING");
+        String timestampFormat = properties.getProperty(TSDBDriver.PROPERTY_KEY_TIMESTAMP_FORMAT, String.valueOf(TimestampFormat.STRING));
         clientInfoProps.setProperty(TSDBDriver.PROPERTY_KEY_TIMESTAMP_FORMAT, timestampFormat);
     }
 
@@ -169,11 +171,7 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
         // do nothing
     }
 
-    @Override
-    public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED);
-
+    private void checkResultSetTypeAndResultSetConcurrency(int resultSetType, int resultSetConcurrency) throws SQLException {
         switch (resultSetType) {
             case ResultSet.TYPE_FORWARD_ONLY:
                 break;
@@ -192,7 +190,14 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
             default:
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_VARIABLE);
         }
+    }
 
+    @Override
+    public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
+        if (isClosed())
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED);
+
+        checkResultSetTypeAndResultSetConcurrency(resultSetType, resultSetConcurrency);
         return createStatement();
     }
 
@@ -201,24 +206,7 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
         if (isClosed())
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED);
 
-        switch (resultSetType) {
-            case ResultSet.TYPE_FORWARD_ONLY:
-                break;
-            case ResultSet.TYPE_SCROLL_INSENSITIVE:
-            case ResultSet.TYPE_SCROLL_SENSITIVE:
-                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-            default:
-                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_VARIABLE);
-        }
-
-        switch (resultSetConcurrency) {
-            case ResultSet.CONCUR_READ_ONLY:
-                break;
-            case ResultSet.CONCUR_UPDATABLE:
-                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
-            default:
-                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_VARIABLE);
-        }
+        checkResultSetTypeAndResultSetConcurrency(resultSetType, resultSetConcurrency);
         return prepareStatement(sql);
     }
 
@@ -304,9 +292,6 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
 
     @Override
     public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED);
-
         switch (resultSetHoldability) {
             case ResultSet.HOLD_CURSORS_OVER_COMMIT:
                 break;
@@ -320,11 +305,7 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
     }
 
     @Override
-    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability)
-            throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED);
-
+    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
         switch (resultSetHoldability) {
             case ResultSet.HOLD_CURSORS_OVER_COMMIT:
                 break;
@@ -423,7 +404,7 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
                 status = resultSet.getInt("server_status()");
                 resultSet.close();
             }
-            return status == 1 ? true : false;
+            return status == 1;
         });
 
         boolean status = false;
@@ -432,9 +413,7 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
                 status = future.get();
             else
                 status = future.get(timeout, TimeUnit.SECONDS);
-        } catch (InterruptedException e) {
-            e.printStackTrace();
-        } catch (ExecutionException e) {
+        } catch (InterruptedException | ExecutionException e) {
             e.printStackTrace();
         } catch (TimeoutException e) {
             future.cancel(true);
@@ -450,8 +429,7 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
         if (isClosed)
             throw (SQLClientInfoException) TSDBError.createSQLException(TSDBErrorNumbers.ERROR_SQLCLIENT_EXCEPTION_ON_CONNECTION_CLOSED);
 
-        if (clientInfoProps != null)
-            clientInfoProps.setProperty(name, value);
+        clientInfoProps.setProperty(name, value);
     }
 
     @Override
@@ -459,8 +437,8 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
         if (isClosed)
             throw (SQLClientInfoException) TSDBError.createSQLException(TSDBErrorNumbers.ERROR_SQLCLIENT_EXCEPTION_ON_CONNECTION_CLOSED);
 
-        for (Enumeration<Object> enumer = properties.keys(); enumer.hasMoreElements(); ) {
-            String name = (String) enumer.nextElement();
+        for (Enumeration<Object> enumeration = properties.keys(); enumeration.hasMoreElements(); ) {
+            String name = (String) enumeration.nextElement();
             clientInfoProps.put(name, properties.getProperty(name));
         }
     }
@@ -516,7 +494,6 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
     public void abort(Executor executor) throws SQLException {
         if (isClosed())
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED);
-
         // do nothing
     }
 
@@ -527,14 +504,13 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
         if (milliseconds < 0)
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_VARIABLE);
 
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        // do nothing
     }
 
     @Override
     public int getNetworkTimeout() throws SQLException {
         if (isClosed())
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED);
-
-        throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
+        return 0;
     }
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractDatabaseMetaData.java

@@ -12,8 +12,7 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
     private final static int DRIVER_MAJAR_VERSION = 2;
     private final static int DRIVER_MINOR_VERSION = 0;
 
-    private String precision = "ms";
-    private String database;
+    private String precision = TSDBConstants.DEFAULT_PRECISION;
 
     public boolean allProceduresAreCallable() throws SQLException {
         return false;
@@ -1223,7 +1222,6 @@ public abstract class AbstractDatabaseMetaData extends WrapperImpl implements Da
             ResultSet databases = stmt.executeQuery("show databases");
             while (databases.next()) {
                 String dbname = databases.getString("name");
-                this.database = dbname;
                 this.precision = databases.getString("precision");
                 if (dbname.equalsIgnoreCase(catalog))
                     return true;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractDriver.java

@@ -58,7 +58,7 @@ public abstract class AbstractDriver implements Driver {
                         value = parameterValuePair.substring(indexOfEqual + 1);
                     }
                 }
-                if ((value != null && value.length() > 0) && (parameter != null && parameter.length() > 0)) {
+                if (value != null && value.length() > 0 && parameter.length() > 0) {
                     urlProps.setProperty(parameter, value);
                 }
             }
@@ -87,7 +87,7 @@ public abstract class AbstractDriver implements Driver {
             url = url.substring(0, indexOfColon);
         }
         // parse host
-        if (url != null && url.length() > 0 && url.trim().length() > 0) {
+        if (url.length() > 0 && url.trim().length() > 0) {
             urlProps.setProperty(TSDBDriver.PROPERTY_KEY_HOST, url);
         }
         return urlProps;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractParameterMetaData.java

 package com.taosdata.jdbc;
 
-import com.sun.org.apache.xpath.internal.operations.Bool;
-
 import java.sql.ParameterMetaData;
 import java.sql.SQLException;
 import java.sql.Timestamp;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractStatement.java

@@ -2,6 +2,7 @@ package com.taosdata.jdbc;
 
 import java.sql.*;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public abstract class AbstractStatement extends WrapperImpl implements Statement {
@@ -9,8 +10,6 @@ public abstract class AbstractStatement extends WrapperImpl implements Statement
     protected List<String> batchedArgs;
     private int fetchSize;
 
-
-
     @Override
     public abstract ResultSet executeQuery(String sql) throws SQLException;
 
@@ -198,13 +197,44 @@ public abstract class AbstractStatement extends WrapperImpl implements Statement
         if (batchedArgs == null || batchedArgs.isEmpty())
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_BATCH_IS_EMPTY);
 
+        String clientInfo = getConnection().getClientInfo(TSDBDriver.PROPERTY_KEY_BATCH_ERROR_IGNORE);
+        boolean batchErrorIgnore = clientInfo == null ? TSDBConstants.DEFAULT_BATCH_ERROR_IGNORE : Boolean.parseBoolean(clientInfo);
+
+        if (batchErrorIgnore) {
+            return executeBatchIgnoreException();
+        }
+        return executeBatchThrowException();
+    }
+
+    private int[] executeBatchIgnoreException() {
+        return batchedArgs.stream().mapToInt(sql -> {
+            try {
+                boolean isSelect = execute(sql);
+                if (isSelect) {
+                    return SUCCESS_NO_INFO;
+                } else {
+                    return getUpdateCount();
+                }
+            } catch (SQLException e) {
+                return EXECUTE_FAILED;
+            }
+        }).toArray();
+    }
+
+    private int[] executeBatchThrowException() throws BatchUpdateException {
         int[] res = new int[batchedArgs.size()];
         for (int i = 0; i < batchedArgs.size(); i++) {
-            boolean isSelect = execute(batchedArgs.get(i));
-            if (isSelect) {
-                res[i] = SUCCESS_NO_INFO;
-            } else {
-                res[i] = getUpdateCount();
+            try {
+                boolean isSelect = execute(batchedArgs.get(i));
+                if (isSelect) {
+                    res[i] = SUCCESS_NO_INFO;
+                } else {
+                    res[i] = getUpdateCount();
+                }
+            } catch (SQLException e) {
+                String reason = e.getMessage();
+                int[] updateCounts = Arrays.copyOfRange(res, 0, i);
+                throw new BatchUpdateException(reason, updateCounts, e);
             }
         }
         return res;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/DatabaseMetaDataResultSet.java

@@ -15,10 +15,12 @@
 package com.taosdata.jdbc;
 
 import java.math.BigDecimal;
-import java.sql.*;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.Calendar;
-import java.util.Iterator;
 import java.util.List;
 
 /*
@@ -130,7 +132,7 @@ public class DatabaseMetaDataResultSet extends AbstractResultSet {
     public Timestamp getTimestamp(int columnIndex) throws SQLException {
         int colType = columnMetaDataList.get(columnIndex - 1).getColType();
         int nativeType = TSDBConstants.jdbcType2TaosType(colType);
-        return rowCursor.getTimestamp(columnIndex,nativeType);
+        return rowCursor.getTimestamp(columnIndex, nativeType);
     }
 
     @Override
@@ -145,9 +147,7 @@ public class DatabaseMetaDataResultSet extends AbstractResultSet {
 
     @Override
     public int findColumn(String columnLabel) throws SQLException {
-        Iterator<ColumnMetaData> colMetaDataIt = this.columnMetaDataList.iterator();
-        while (colMetaDataIt.hasNext()) {
-            ColumnMetaData colMetaData = colMetaDataIt.next();
+        for (ColumnMetaData colMetaData : this.columnMetaDataList) {
             if (colMetaData.getColName() != null && colMetaData.getColName().equals(columnLabel)) {
                 return colMetaData.getColIndex();
             }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/EmptyResultSet.java

@@ -23,7 +23,7 @@ import java.util.Calendar;
 import java.util.Map;
 
 /*
- * TDengine only supports a subset of the standard SQL, thus this implemetation of the
+ * TDengine only supports a subset of the standard SQL, thus this implementation of the
  * standard JDBC API contains more or less some adjustments customized for certain
  * compatibility needs.
  */
@@ -326,7 +326,7 @@ public class EmptyResultSet implements ResultSet {
 
     @Override
     public int getFetchDirection() throws SQLException {
-        return 0;
+        return ResultSet.FETCH_FORWARD;
     }
 
     @Override
@@ -341,12 +341,12 @@ public class EmptyResultSet implements ResultSet {
 
     @Override
     public int getType() throws SQLException {
-        return 0;
+        return ResultSet.TYPE_FORWARD_ONLY;
     }
 
     @Override
     public int getConcurrency() throws SQLException {
-        return 0;
+        return ResultSet.CONCUR_READ_ONLY;
     }
 
     @Override
@@ -746,7 +746,7 @@ public class EmptyResultSet implements ResultSet {
 
     @Override
     public int getHoldability() throws SQLException {
-        return 0;
+        return ResultSet.CLOSE_CURSORS_AT_COMMIT;
     }
 
     @Override

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBConnection.java

@@ -20,7 +20,7 @@ import java.util.Properties;
 public class TSDBConnection extends AbstractConnection {
 
     private TSDBJNIConnector connector;
-    private TSDBDatabaseMetaData databaseMetaData;
+    private final TSDBDatabaseMetaData databaseMetaData;
     private boolean batchFetch;
 
     public Boolean getBatchFetch() {

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBConstants.java

@@ -54,10 +54,11 @@ public abstract class TSDBConstants {
     public static final int TSDB_DATA_TYPE_USMALLINT = 12;      //unsigned smallint
     public static final int TSDB_DATA_TYPE_UINT = 13;           //unsigned int
     public static final int TSDB_DATA_TYPE_UBIGINT = 14;        //unsigned bigint
+
     // nchar column max length
     public static final int maxFieldSize = 16 * 1024;
 
-    // precision for data types
+    // precision for data types, this is used for metadata
     public static final int BOOLEAN_PRECISION = 1;
     public static final int TINYINT_PRECISION = 4;
     public static final int SMALLINT_PRECISION = 6;
@@ -67,10 +68,14 @@ public abstract class TSDBConstants {
     public static final int DOUBLE_PRECISION = 22;
     public static final int TIMESTAMP_MS_PRECISION = 23;
     public static final int TIMESTAMP_US_PRECISION = 26;
-    // scale for data types
+    // scale for data types, this is used for metadata
     public static final int FLOAT_SCALE = 31;
     public static final int DOUBLE_SCALE = 31;
 
+    public static final String DEFAULT_PRECISION = "ms";
+
+    public static final boolean DEFAULT_BATCH_ERROR_IGNORE = false;
+
     public static int typeName2JdbcType(String type) {
         switch (type.toUpperCase()) {
             case "TIMESTAMP":

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBDatabaseMetaData.java

@@ -20,8 +20,8 @@ import java.sql.SQLException;
 
 public class TSDBDatabaseMetaData extends AbstractDatabaseMetaData {
 
-    private String url;
-    private String userName;
+    private final String url;
+    private final String userName;
     private Connection conn;
 
     public TSDBDatabaseMetaData(String url, String userName) {

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBDriver.java

@@ -100,6 +100,11 @@ public class TSDBDriver extends AbstractDriver {
      */
     public static final String PROPERTY_KEY_TIMESTAMP_FORMAT = "timestampFormat";
 
+    /**
+     * continue process commands in executeBatch
+     */
+    public static final String PROPERTY_KEY_BATCH_ERROR_IGNORE = "batchErrorIgnore";
+
     private TSDBDatabaseMetaData dbMetaData = null;
 
     static {
@@ -176,7 +181,7 @@ public class TSDBDriver extends AbstractDriver {
         int beginningOfSlashes = url.indexOf("//");
         int index = url.indexOf("?");
         if (index != -1) {
-            String paramString = url.substring(index + 1, url.length());
+            String paramString = url.substring(index + 1);
             url = url.substring(0, index);
             StringTokenizer queryParams = new StringTokenizer(paramString, "&");
             while (queryParams.hasMoreElements()) {
@@ -213,7 +218,7 @@ public class TSDBDriver extends AbstractDriver {
             url = url.substring(0, indexOfColon);
         }
 
-        if (url != null && url.length() > 0 && url.trim().length() > 0) {
+        if (url.length() > 0 && url.trim().length() > 0) {
             urlProps.setProperty(TSDBDriver.PROPERTY_KEY_HOST, url);
         }
 
@@ -233,7 +238,7 @@ public class TSDBDriver extends AbstractDriver {
         return false;
     }
 
-    public Logger getParentLogger() throws SQLFeatureNotSupportedException {
+    public Logger getParentLogger() {
         return null;
     }
 

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBError.java

@@ -8,7 +8,7 @@ import java.util.HashMap;
 import java.util.Map;
 
 public class TSDBError {
-    private static Map<Integer, String> TSDBErrorMap = new HashMap<>();
+    private static final Map<Integer, String> TSDBErrorMap = new HashMap<>();
 
     static {
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_CONNECTION_CLOSED, "connection already closed");
@@ -32,10 +32,10 @@ public class TSDBError {
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_INVALID_SQL, "invalid sql");
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE, "numeric value out of range");
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_UNKNOWN_TAOS_TYPE_IN_TDENGINE, "unknown taos type in tdengine");
+        TSDBErrorMap.put(TSDBErrorNumbers.ERROR_UNKNOWN_TIMESTAMP_PERCISION, "unknown timestamp precision");
 
-        /**************************************************/
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_UNKNOWN, "unknown error");
-        /**************************************************/
+
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_SUBSCRIBE_FAILED, "failed to create subscription");
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_UNSUPPORTED_ENCODING, "Unsupported encoding");
         TSDBErrorMap.put(TSDBErrorNumbers.ERROR_JNI_TDENGINE_ERROR, "internal error of database");

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBErrorNumbers.java

 package com.taosdata.jdbc;
 
 import java.util.HashSet;
+import java.util.Set;
 
 public class TSDBErrorNumbers {
 
@@ -25,6 +26,7 @@ public class TSDBErrorNumbers {
     public static final int ERROR_INVALID_SQL = 0x2313;     // invalid sql
     public static final int ERROR_NUMERIC_VALUE_OUT_OF_RANGE = 0x2314;  // numeric value out of range
     public static final int ERROR_UNKNOWN_TAOS_TYPE_IN_TDENGINE = 0x2315; //unknown taos type in tdengine
+    public static final int ERROR_UNKNOWN_TIMESTAMP_PERCISION = 0x2316;     // unknown timestamp precision
 
     public static final int ERROR_UNKNOWN = 0x2350;    //unknown error
 
@@ -38,10 +40,9 @@ public class TSDBErrorNumbers {
     public static final int ERROR_JNI_FETCH_END = 0x2358;       // fetch to the end of resultSet
     public static final int ERROR_JNI_OUT_OF_MEMORY = 0x2359;   // JNI alloc memory failed
 
-    private static final HashSet<Integer> errorNumbers;
+    private static final Set<Integer> errorNumbers = new HashSet<>();
 
     static {
-        errorNumbers = new HashSet();
         errorNumbers.add(ERROR_CONNECTION_CLOSED);
         errorNumbers.add(ERROR_UNSUPPORTED_METHOD);
         errorNumbers.add(ERROR_INVALID_VARIABLE);
@@ -62,8 +63,8 @@ public class TSDBErrorNumbers {
         errorNumbers.add(ERROR_INVALID_SQL);
         errorNumbers.add(ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
         errorNumbers.add(ERROR_UNKNOWN_TAOS_TYPE_IN_TDENGINE);
+        errorNumbers.add(ERROR_UNKNOWN_TIMESTAMP_PERCISION);
 
-        /*****************************************************/
         errorNumbers.add(ERROR_SUBSCRIBE_FAILED);
         errorNumbers.add(ERROR_UNSUPPORTED_ENCODING);
         errorNumbers.add(ERROR_JNI_TDENGINE_ERROR);

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBJNIConnector.java

@@ -29,14 +29,9 @@ import java.util.List;
 public class TSDBJNIConnector {
     private static volatile Boolean isInitialized = false;
 
-    private TaosInfo taosInfo = TaosInfo.getInstance();
-
-    // Connection pointer used in C
-    private long taos = TSDBConstants.JNI_NULL_POINTER;
-
-    // result set status in current connection
-    private boolean isResultsetClosed;
-
+    private final TaosInfo taosInfo = TaosInfo.getInstance();
+    private long taos = TSDBConstants.JNI_NULL_POINTER;     // Connection pointer used in C
+    private boolean isResultsetClosed;      // result set status in current connection
     private int affectedRows = -1;
 
     static {
@@ -96,11 +91,9 @@ public class TSDBJNIConnector {
 
     /**
      * Execute DML/DDL operation
-     *
-     * @throws SQLException
      */
     public long executeQuery(String sql) throws SQLException {
-        Long pSql = 0l;
+        long pSql = 0L;
         try {
             pSql = this.executeQueryImp(sql.getBytes(TaosGlobalConfig.getCharset()), this.taos);
             taosInfo.stmt_count_increment();
@@ -161,7 +154,7 @@ public class TSDBJNIConnector {
     private native long getResultSetImp(long connection, long pSql);
 
     public boolean isUpdateQuery(long pSql) {
-        return isUpdateQueryImp(this.taos, pSql) == 1 ? true : false;
+        return isUpdateQueryImp(this.taos, pSql) == 1;
     }
 
     private native long isUpdateQueryImp(long connection, long pSql);
@@ -195,7 +188,7 @@ public class TSDBJNIConnector {
      */
     public int getSchemaMetaData(long resultSet, List<ColumnMetaData> columnMetaData) {
         int ret = this.getSchemaMetaDataImp(this.taos, resultSet, columnMetaData);
-        columnMetaData.stream().forEach(column -> column.setColIndex(column.getColIndex() + 1));
+        columnMetaData.forEach(column -> column.setColIndex(column.getColIndex() + 1));
         return ret;
     }
 
@@ -217,9 +210,18 @@ public class TSDBJNIConnector {
     private native int fetchBlockImp(long connection, long resultSet, TSDBResultSetBlockData blockData);
 
     /**
-     * Execute close operation from C to release connection pointer by JNI
+     * Get Result Time Precision.
      *
-     * @throws SQLException
+     * @return 0: ms, 1: us, 2: ns
+     */
+    public int getResultTimePrecision(long sqlObj) {
+        return this.getResultTimePrecisionImp(this.taos, sqlObj);
+    }
+
+    private native int getResultTimePrecisionImp(long connection, long result);
+
+    /**
+     * Execute close operation from C to release connection pointer by JNI
      */
     public void closeConnection() throws SQLException {
         int code = this.closeConnectionImp(this.taos);
@@ -258,8 +260,6 @@ public class TSDBJNIConnector {
 
     /**
      * Unsubscribe, close a subscription
-     *
-     * @param subscription
      */
     void unsubscribe(long subscription, boolean isKeep) {
         unsubscribeImp(subscription, isKeep);
@@ -272,13 +272,13 @@ public class TSDBJNIConnector {
      */
     public boolean validateCreateTableSql(String sql) {
         int res = validateCreateTableSqlImp(taos, sql.getBytes());
-        return res != 0 ? false : true;
+        return res == 0;
     }
 
     private native int validateCreateTableSqlImp(long connection, byte[] sqlBytes);
 
     public long prepareStmt(String sql) throws SQLException {
-        Long stmt;
+        long stmt;
         try {
             stmt = prepareStmtImp(sql.getBytes(), this.taos);
         } catch (Exception e) {
@@ -348,4 +348,13 @@ public class TSDBJNIConnector {
     }
 
     private native int closeStmt(long stmt, long con);
+
+    public void insertLines(String[] lines) throws SQLException {
+        int code = insertLinesImp(lines, this.taos);
+        if (code != TSDBConstants.JNI_SUCCESS) {
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "failed to insertLines");
+        }
+    }
+
+    private native int insertLinesImp(String[] lines, long conn);
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBPreparedStatement.java

@@ -38,7 +38,6 @@ import java.util.regex.Pattern;
 public class TSDBPreparedStatement extends TSDBStatement implements PreparedStatement {
     private String rawSql;
     private Object[] parameters;
-    private boolean isPrepared;
 
     private ArrayList<ColumnInfo> colData;
     private ArrayList<TableTagInfo> tableTags;
@@ -47,8 +46,6 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
     private String tableName;
     private long nativeStmtHandle = 0;
 
-    private volatile TSDBParameterMetaData parameterMetaData;
-
     TSDBPreparedStatement(TSDBConnection connection, String sql) {
         super(connection);
         init(sql);
@@ -60,14 +57,13 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
                     parameterCnt++;
                 }
             }
-            parameters = new Object[parameterCnt];
-            this.isPrepared = true;
         }
+        parameters = new Object[parameterCnt];
 
         if (parameterCnt > 1) {
             // the table name is also a parameter, so ignore it.
-            this.colData = new ArrayList<ColumnInfo>();
-            this.tableTags = new ArrayList<TableTagInfo>();
+            this.colData = new ArrayList<>();
+            this.tableTags = new ArrayList<>();
         }
     }
 
@@ -76,18 +72,17 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
         preprocessSql();
     }
 
-    @Override
-    public int[] executeBatch() throws SQLException {
-        return super.executeBatch();
-    }
-
     /*
+     *
+     */
+
+    /**
      * Some of the SQLs sent by other popular frameworks or tools like Spark, contains syntax that cannot be parsed by
      * the TDengine client. Thus, some simple parsers/filters are intentionally added in this JDBC implementation in
      * order to process those supported SQLs.
      */
     private void preprocessSql() {
-        /***** For processing some of Spark SQLs*****/
+        /***For processing some of Spark SQLs*/
         // should replace it first
         this.rawSql = this.rawSql.replaceAll("or (.*) is null", "");
         this.rawSql = this.rawSql.replaceAll(" where ", " WHERE ");
@@ -134,32 +129,17 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
             }
             rawSql = rawSql.replace(matcher.group(1), tableFullName);
         }
-        /***** for inner queries *****/
-    }
-
-    /**
-     * Populate parameters into prepared sql statements
-     *
-     * @return a string of the native sql statement for TSDB
-     */
-    private String getNativeSql(String rawSql) throws SQLException {
-        return Utils.getNativeSql(rawSql, this.parameters);
     }
 
     @Override
     public ResultSet executeQuery() throws SQLException {
-        if (!isPrepared)
-            return executeQuery(this.rawSql);
-
-        final String sql = getNativeSql(this.rawSql);
+        final String sql = Utils.getNativeSql(this.rawSql, this.parameters);
         return executeQuery(sql);
     }
 
     @Override
     public int executeUpdate() throws SQLException {
-        if (!isPrepared)
-            return executeUpdate(this.rawSql);
-        String sql = getNativeSql(this.rawSql);
+        String sql = Utils.getNativeSql(this.rawSql, this.parameters);
         return executeUpdate(sql);
     }
 
@@ -282,25 +262,14 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
 
     @Override
     public boolean execute() throws SQLException {
-        if (!isPrepared)
-            return execute(this.rawSql);
-
-        final String sql = getNativeSql(this.rawSql);
+        final String sql = Utils.getNativeSql(this.rawSql, this.parameters);
         return execute(sql);
     }
 
     @Override
     public void addBatch() throws SQLException {
-        if (this.batchedArgs == null) {
-            batchedArgs = new ArrayList<>();
-        }
-
-        if (!isPrepared) {
-            addBatch(this.rawSql);
-        } else {
-            String sql = this.getConnection().nativeSQL(this.rawSql);
-            addBatch(sql);
-        }
+        String sql = Utils.getNativeSql(this.rawSql, this.parameters);
+        addBatch(sql);
     }
 
     @Override
@@ -553,12 +522,10 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
         }
     }
 
-    ;
-
     private static class TableTagInfo {
         private boolean isNull;
-        private Object value;
-        private int type;
+        private final Object value;
+        private final int type;
 
         public TableTagInfo(Object value, int type) {
             this.value = value;
@@ -572,8 +539,6 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
         }
     }
 
-    ;
-
     public void setTableName(String name) {
         this.tableName = name;
     }
@@ -661,7 +626,7 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
             this.colData.addAll(Collections.nCopies(this.parameters.length - 1 - this.tableTags.size(), null));
         }
 
-        ColumnInfo col = (ColumnInfo) this.colData.get(columnIndex);
+        ColumnInfo col = this.colData.get(columnIndex);
         if (col == null) {
             ColumnInfo p = new ColumnInfo();
             p.setType(type);
@@ -752,8 +717,7 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
             ByteBuffer isNullList = ByteBuffer.allocate(num * Integer.BYTES);
             isNullList.order(ByteOrder.LITTLE_ENDIAN);
 
-            for (int i = 0; i < num; ++i) {
-                TableTagInfo tag = this.tableTags.get(i);
+            for (TableTagInfo tag : this.tableTags) {
                 if (tag.isNull) {
                     typeList.put((byte) tag.type);
                     isNullList.putInt(1);
@@ -852,7 +816,7 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
                     typeList, lengthList, isNullList);
         }
 
-        ColumnInfo colInfo = (ColumnInfo) this.colData.get(0);
+        ColumnInfo colInfo = this.colData.get(0);
         if (colInfo == null) {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "column data not bind");
         }
@@ -988,7 +952,6 @@ public class TSDBPreparedStatement extends TSDBStatement implements PreparedStat
                     throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN, "not support data types");
                 }
             }
-            ;
 
             connector.bindColumnDataArray(this.nativeStmtHandle, colDataList, lengthList, isNullList, col1.type, col1.bytes, rows, i);
         }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSet.java

@@ -339,11 +339,11 @@ public class TSDBResultSet extends AbstractResultSet implements ResultSet {
                 case TSDBConstants.TSDB_DATA_TYPE_SMALLINT:
                 case TSDBConstants.TSDB_DATA_TYPE_INT:
                 case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
-                    res = new BigDecimal(Long.valueOf(this.rowData.getObject(columnIndex).toString()));
+                    res = new BigDecimal(Long.parseLong(this.rowData.getObject(columnIndex).toString()));
                     break;
                 case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
                 case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
-                    res = new BigDecimal(Double.valueOf(this.rowData.getObject(columnIndex).toString()));
+                    res = BigDecimal.valueOf(Double.parseDouble(this.rowData.getObject(columnIndex).toString()));
                     break;
                 case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
                     return new BigDecimal(((Timestamp) this.rowData.getObject(columnIndex)).getTime());

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSetBlockData.java

@@ -36,23 +36,20 @@ public class TSDBResultSetBlockData {
     private int rowIndex = 0;
 
     private List<ColumnMetaData> columnMetaDataList;
-    private ArrayList<Object> colData = null;
+    private ArrayList<Object> colData;
 
     public TSDBResultSetBlockData(List<ColumnMetaData> colMeta, int numOfCols) {
         this.columnMetaDataList = colMeta;
-        this.colData = new ArrayList<Object>(numOfCols);
+        this.colData = new ArrayList<>(numOfCols);
     }
 
     public TSDBResultSetBlockData() {
-        this.colData = new ArrayList<Object>();
+        this.colData = new ArrayList<>();
     }
 
     public void clear() {
         int size = this.colData.size();
-        if (this.colData != null) {
-            this.colData.clear();
-        }
-
+        this.colData.clear();
         setNumOfCols(size);
     }
 
@@ -69,7 +66,7 @@ public class TSDBResultSetBlockData {
     }
 
     public void setNumOfCols(int numOfCols) {
-        this.colData = new ArrayList<Object>(numOfCols);
+        this.colData = new ArrayList<>(numOfCols);
         this.colData.addAll(Collections.nCopies(numOfCols, null));
     }
 
@@ -166,15 +163,10 @@ public class TSDBResultSetBlockData {
         }
     }
 
-    
 
     /**
      * The original type may not be a string type, but will be converted to by
      * calling this method
-     *
-     * @param col column index
-     * @return
-     * @throws SQLException
      */
     public String getString(int col) throws SQLException {
         Object obj = get(col);
@@ -387,7 +379,7 @@ public class TSDBResultSetBlockData {
                     return null;
                 }
 
-                return (long) val;
+                return val;
             }
 
             case TSDBConstants.TSDB_DATA_TYPE_FLOAT: {

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSetMetaData.java

@@ -41,10 +41,7 @@ public class TSDBResultSetMetaData extends WrapperImpl implements ResultSetMetaD
     }
 
     public boolean isSearchable(int column) throws SQLException {
-        if (column == 1) {
-            return true;
-        }
-        return false;
+        return column == 1;
     }
 
     public boolean isCurrency(int column) throws SQLException {

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSetRowData.java

@@ -26,7 +26,7 @@ import java.util.Collections;
 public class TSDBResultSetRowData {
 
     private ArrayList<Object> data;
-    private int colSize;
+    private final int colSize;
 
     public TSDBResultSetRowData(int colSize) {
         this.colSize = colSize;
@@ -147,30 +147,14 @@ public class TSDBResultSetRowData {
             case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
             case TSDBConstants.TSDB_DATA_TYPE_BINARY:
                 return Integer.parseInt((String) obj);
-            case TSDBConstants.TSDB_DATA_TYPE_UTINYINT: {
-                Byte value = (byte) obj;
-                if (value < 0)
-                    throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
-                return value;
-            }
-            case TSDBConstants.TSDB_DATA_TYPE_USMALLINT: {
-                short value = (short) obj;
-                if (value < 0)
-                    throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
-                return value;
-            }
-            case TSDBConstants.TSDB_DATA_TYPE_UINT: {
-                int value = (int) obj;
-                if (value < 0)
-                    throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
-                return value;
-            }
-            case TSDBConstants.TSDB_DATA_TYPE_UBIGINT: {
-                long value = (long) obj;
-                if (value < 0)
-                    throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
-                return Long.valueOf(value).intValue();
-            }
+            case TSDBConstants.TSDB_DATA_TYPE_UTINYINT:
+                return parseUnsignedTinyIntToInt(obj);
+            case TSDBConstants.TSDB_DATA_TYPE_USMALLINT:
+                return parseUnsignedSmallIntToInt(obj);
+            case TSDBConstants.TSDB_DATA_TYPE_UINT:
+                return parseUnsignedIntegerToInt(obj);
+            case TSDBConstants.TSDB_DATA_TYPE_UBIGINT:
+                return parseUnsignedBigIntToInt(obj);
             case TSDBConstants.TSDB_DATA_TYPE_FLOAT:
                 return ((Float) obj).intValue();
             case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
@@ -180,6 +164,35 @@ public class TSDBResultSetRowData {
         }
     }
 
+    private byte parseUnsignedTinyIntToInt(Object obj) throws SQLException {
+        byte value = (byte) obj;
+        if (value < 0)
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
+        return value;
+    }
+
+    private short parseUnsignedSmallIntToInt(Object obj) throws SQLException {
+        short value = (short) obj;
+        if (value < 0)
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
+        return value;
+    }
+
+    private int parseUnsignedIntegerToInt(Object obj) throws SQLException {
+        int value = (int) obj;
+        if (value < 0)
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
+        return value;
+    }
+
+    private int parseUnsignedBigIntToInt(Object obj) throws SQLException {
+        long value = (long) obj;
+        if (value < 0)
+            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
+        return Long.valueOf(value).intValue();
+    }
+
+
     /**
      * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
      */
@@ -216,7 +229,7 @@ public class TSDBResultSetRowData {
             case TSDBConstants.TSDB_DATA_TYPE_BINARY:
                 return Long.parseLong((String) obj);
             case TSDBConstants.TSDB_DATA_TYPE_UTINYINT: {
-                Byte value = (byte) obj;
+                byte value = (byte) obj;
                 if (value < 0)
                     throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_NUMERIC_VALUE_OUT_OF_RANGE);
                 return value;
@@ -377,27 +390,27 @@ public class TSDBResultSetRowData {
 
         switch (nativeType) {
             case TSDBConstants.TSDB_DATA_TYPE_UTINYINT: {
-                Byte value = new Byte(String.valueOf(obj));
+                byte value = new Byte(String.valueOf(obj));
                 if (value >= 0)
-                    return value.toString();
+                    return Byte.toString(value);
                 return Integer.toString(value & 0xff);
             }
             case TSDBConstants.TSDB_DATA_TYPE_USMALLINT: {
-                Short value = new Short(String.valueOf(obj));
+                short value = new Short(String.valueOf(obj));
                 if (value >= 0)
-                    return value.toString();
+                    return Short.toString(value);
                 return Integer.toString(value & 0xffff);
             }
             case TSDBConstants.TSDB_DATA_TYPE_UINT: {
-                Integer value = new Integer(String.valueOf(obj));
+                int value = new Integer(String.valueOf(obj));
                 if (value >= 0)
-                    return value.toString();
-                return Long.toString(value & 0xffffffffl);
+                    return Integer.toString(value);
+                return Long.toString(value & 0xffffffffL);
             }
             case TSDBConstants.TSDB_DATA_TYPE_UBIGINT: {
-                Long value = new Long(String.valueOf(obj));
+                long value = new Long(String.valueOf(obj));
                 if (value >= 0)
-                    return value.toString();
+                    return Long.toString(value);
                 long lowValue = value & 0x7fffffffffffffffL;
                 return BigDecimal.valueOf(lowValue).add(BigDecimal.valueOf(Long.MAX_VALUE)).add(BigDecimal.valueOf(1)).toString();
             }
@@ -414,11 +427,45 @@ public class TSDBResultSetRowData {
      * $$$ this method is invoked by databaseMetaDataResultSet and so on which use a index start from 1 in JDBC api
      */
     public void setTimestampValue(int colIndex, long value) {
-        setTimestamp(colIndex - 1, value);
+        setTimestamp(colIndex - 1, value, 0);
     }
 
     /**
      * !!! this method is invoked by JNI method and the index start from 0 in C implementations
+     *
+     * @param precision 0 : ms, 1 : us, 2 : ns
+     */
+    public void setTimestamp(int col, long ts, int precision) {
+        long milliseconds;
+        int fracNanoseconds;
+        switch (precision) {
+            case 0: {
+                milliseconds = ts;
+                fracNanoseconds = (int) (ts * 1_000_000 % 1_000_000_000);
+                break;
+            }
+            case 1: {
+                milliseconds = ts / 1_000;
+                fracNanoseconds = (int) (ts * 1_000 % 1_000_000_000);
+                break;
+            }
+            case 2: {
+                milliseconds = ts / 1_000_000;
+                fracNanoseconds = (int) (ts % 1_000_000_000);
+                break;
+            }
+            default: {
+                throw new IllegalArgumentException("precision is not valid. precision: " + precision);
+            }
+        }
+
+        Timestamp tsObj = new Timestamp(milliseconds);
+        tsObj.setNanos(fracNanoseconds);
+        data.set(col, tsObj);
+    }
+
+    /**
+     * this implementation is used for TDengine old version
      */
     public void setTimestamp(int col, long ts) {
         //TODO: this implementation contains logical error
@@ -429,8 +476,8 @@ public class TSDBResultSetRowData {
         if (ts < 1_0000_0000_0000_0L) {
             data.set(col, new Timestamp(ts));
         } else {
-            long epochSec = ts / 1000_000l;
-            long nanoAdjustment = ts % 1000_000l * 1000l;
+            long epochSec = ts / 1000_000L;
+            long nanoAdjustment = ts % 1000_000L * 1000L;
             Timestamp timestamp = Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
             data.set(col, timestamp);
         }
@@ -440,12 +487,10 @@ public class TSDBResultSetRowData {
         Object obj = data.get(col - 1);
         if (obj == null)
             return null;
-        switch (nativeType) {
-            case TSDBConstants.TSDB_DATA_TYPE_BIGINT:
-                return new Timestamp((Long) obj);
-            default:
-                return (Timestamp) obj;
+        if (nativeType == TSDBConstants.TSDB_DATA_TYPE_BIGINT) {
+            return new Timestamp((Long) obj);
         }
+        return (Timestamp) obj;
     }
 
     public Object getObject(int col) {

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBSubscribe.java

@@ -47,9 +47,6 @@ public class TSDBSubscribe {
 
     /**
      * close subscription
-     *
-     * @param keepProgress
-     * @throws SQLException
      */
     public void close(boolean keepProgress) throws SQLException {
         if (this.connecter.isClosed())

src/connector/jdbc/src/main/java/com/taosdata/jdbc/enums/TimestampFormat.java

+package com.taosdata.jdbc.enums;
+
+public enum TimestampFormat {
+    STRING,
+    TIMESTAMP,
+    UTC
+}

src/connector/jdbc/src/main/java/com/taosdata/jdbc/enums/TimestampPrecision.java

+package com.taosdata.jdbc.enums;
+
+public enum TimestampPrecision {
+    MS,
+    US,
+    NS,
+    UNKNOWN
+}

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulConnection.java

@@ -16,7 +16,7 @@ public class RestfulConnection extends AbstractConnection {
     private final String host;
     private final int port;
     private final String url;
-    private volatile String database;
+    private final String database;
     private final String token;
     /******************************************************/
     private boolean isClosed;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulPreparedStatement.java

@@ -13,7 +13,7 @@ import java.util.Calendar;
 
 public class RestfulPreparedStatement extends RestfulStatement implements PreparedStatement {
 
-    private ParameterMetaData parameterMetaData;
+    private final ParameterMetaData parameterMetaData;
     private final String rawSql;
     private Object[] parameters;
     private boolean isPrepared;
@@ -22,16 +22,16 @@ public class RestfulPreparedStatement extends RestfulStatement implements Prepar
         super(conn, database);
         this.rawSql = sql;
 
+        int parameterCnt = 0;
         if (sql.contains("?")) {
-            int parameterCnt = 0;
             for (int i = 0; i < sql.length(); i++) {
                 if ('?' == sql.charAt(i)) {
                     parameterCnt++;
                 }
             }
-            parameters = new Object[parameterCnt];
             this.isPrepared = true;
         }
+        parameters = new Object[parameterCnt];
 
         // build parameterMetaData
         this.parameterMetaData = new RestfulParameterMetaData(parameters);
@@ -44,7 +44,7 @@ public class RestfulPreparedStatement extends RestfulStatement implements Prepar
         if (!isPrepared)
             return executeQuery(this.rawSql);
 
-        final String sql = getNativeSql(this.rawSql);
+        final String sql = Utils.getNativeSql(this.rawSql, this.parameters);
         return executeQuery(sql);
     }
 
@@ -55,20 +55,10 @@ public class RestfulPreparedStatement extends RestfulStatement implements Prepar
         if (!isPrepared)
             return executeUpdate(this.rawSql);
 
-        final String sql = getNativeSql(this.rawSql);
+        final String sql = Utils.getNativeSql(rawSql, this.parameters);
         return executeUpdate(sql);
     }
 
-    /****
-     * 将rawSql转换成一条可执行的sql语句，使用属性parameters中的变脸进行替换
-     * 对于insert into ?.? (?,?,?) using ?.? (?,?,?) tags(?, ?, ?) values(?, ?, ?)
-     * @param rawSql，可能是insert、select或其他，使用?做占位符
-     * @return
-     */
-    private String getNativeSql(String rawSql) {
-        return Utils.getNativeSql(rawSql, this.parameters);
-    }
-
     @Override
     public void setNull(int parameterIndex, int sqlType) throws SQLException {
         if (isClosed())
@@ -224,16 +214,13 @@ public class RestfulPreparedStatement extends RestfulStatement implements Prepar
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
         if (!isPrepared)
             return execute(this.rawSql);
-        final String sql = getNativeSql(rawSql);
+        final String sql = Utils.getNativeSql(rawSql, this.parameters);
         return execute(sql);
     }
 
     @Override
     public void addBatch() throws SQLException {
-        if (isClosed())
-            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_STATEMENT_CLOSED);
-
-        final String sql = getNativeSql(this.rawSql);
+        final String sql = Utils.getNativeSql(rawSql, this.parameters);
         addBatch(sql);
     }
 

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulResultSet.java

@@ -6,6 +6,8 @@ import com.google.common.primitives.Ints;
 import com.google.common.primitives.Longs;
 import com.google.common.primitives.Shorts;
 import com.taosdata.jdbc.*;
+import com.taosdata.jdbc.enums.TimestampPrecision;
+import com.taosdata.jdbc.enums.TimestampFormat;
 import com.taosdata.jdbc.utils.Utils;
 
 import java.math.BigDecimal;
@@ -15,19 +17,20 @@ import java.time.ZoneOffset;
 import java.time.format.DateTimeParseException;
 import java.util.ArrayList;
 import java.util.Calendar;
+import java.util.List;
 
 public class RestfulResultSet extends AbstractResultSet implements ResultSet {
-    private volatile boolean isClosed;
-    private int pos = -1;
 
-    private final String database;
     private final Statement statement;
     // data
-    private final ArrayList<ArrayList<Object>> resultSet = new ArrayList<>();
+    private final List<List<Object>> resultSet = new ArrayList<>();
     // meta
-    private ArrayList<String> columnNames = new ArrayList<>();
-    private ArrayList<Field> columns = new ArrayList<>();
-    private RestfulResultSetMetaData metaData;
+    private final List<String> columnNames = new ArrayList<>();
+    private final List<Field> columns = new ArrayList<>();
+    private final RestfulResultSetMetaData metaData;
+
+    private volatile boolean isClosed;
+    private int pos = -1;
 
     /**
      * 由一个result的Json构造结果集，对应执行show databases, show tables等这些语句，返回结果集，但无法获取结果集对应的meta，统一当成String处理
@@ -35,34 +38,30 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
      * @param resultJson: 包含data信息的结果集，有sql返回的结果集
      ***/
     public RestfulResultSet(String database, Statement statement, JSONObject resultJson) throws SQLException {
-        this.database = database;
         this.statement = statement;
 
+        // get head
+        JSONArray head = resultJson.getJSONArray("head");
         // get column metadata
         JSONArray columnMeta = resultJson.getJSONArray("column_meta");
         // get row data
         JSONArray data = resultJson.getJSONArray("data");
-        if (data == null || data.isEmpty()) {
-            columnNames.clear();
-            columns.clear();
-            this.resultSet.clear();
-            return;
-        }
-        // get head
-        JSONArray head = resultJson.getJSONArray("head");
         // get rows
         Integer rows = resultJson.getInteger("rows");
+
         // parse column_meta
         if (columnMeta != null) {
             parseColumnMeta_new(columnMeta);
         } else {
             parseColumnMeta_old(head, data, rows);
         }
-        this.metaData = new RestfulResultSetMetaData(this.database, columns, this);
+        this.metaData = new RestfulResultSetMetaData(database, columns, this);
+
+        if (data == null || data.isEmpty())
+            return;
         // parse row data
-        resultSet.clear();
         for (int rowIndex = 0; rowIndex < data.size(); rowIndex++) {
-            ArrayList row = new ArrayList();
+            List<Object> row = new ArrayList<>();
             JSONArray jsonRow = data.getJSONArray(rowIndex);
             for (int colIndex = 0; colIndex < this.metaData.getColumnCount(); colIndex++) {
                 row.add(parseColumnData(jsonRow, colIndex, columns.get(colIndex).taos_type));
@@ -131,7 +130,6 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         }
     }
 
-
     private Object parseColumnData(JSONArray row, int colIndex, int taosType) throws SQLException {
         switch (taosType) {
             case TSDBConstants.TSDB_DATA_TYPE_NULL:
@@ -150,44 +148,8 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
                 return row.getFloat(colIndex);
             case TSDBConstants.TSDB_DATA_TYPE_DOUBLE:
                 return row.getDouble(colIndex);
-            case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP: {
-                if (row.get(colIndex) == null)
-                    return null;
-                String timestampFormat = this.statement.getConnection().getClientInfo(TSDBDriver.PROPERTY_KEY_TIMESTAMP_FORMAT);
-                if ("TIMESTAMP".equalsIgnoreCase(timestampFormat)) {
-                    Long value = row.getLong(colIndex);
-                    //TODO: this implementation has bug if the timestamp bigger than 9999_9999_9999_9
-                    if (value < 1_0000_0000_0000_0L)
-                        return new Timestamp(value);
-                    long epochSec = value / 1000_000l;
-                    long nanoAdjustment = value % 1000_000l * 1000l;
-                    return Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
-                }
-                if ("UTC".equalsIgnoreCase(timestampFormat)) {
-                    String value = row.getString(colIndex);
-                    long epochSec = Timestamp.valueOf(value.substring(0, 19).replace("T", " ")).getTime() / 1000;
-                    int fractionalSec = Integer.parseInt(value.substring(20, value.length() - 5));
-                    long nanoAdjustment = 0;
-                    if (value.length() > 28) {
-                        // ms timestamp: yyyy-MM-ddTHH:mm:ss.SSSSSS+0x00
-                        nanoAdjustment = fractionalSec * 1000l;
-                    } else {
-                        // ms timestamp: yyyy-MM-ddTHH:mm:ss.SSS+0x00
-                        nanoAdjustment = fractionalSec * 1000_000l;
-                    }
-                    ZoneOffset zoneOffset = ZoneOffset.of(value.substring(value.length() - 5));
-                    Instant instant = Instant.ofEpochSecond(epochSec, nanoAdjustment).atOffset(zoneOffset).toInstant();
-                    return Timestamp.from(instant);
-                }
-                String value = row.getString(colIndex);
-                if (value.length() <= 23)    // ms timestamp: yyyy-MM-dd HH:mm:ss.SSS
-                    return row.getTimestamp(colIndex);
-                // us timestamp: yyyy-MM-dd HH:mm:ss.SSSSSS
-                long epochSec = Timestamp.valueOf(value.substring(0, 19)).getTime() / 1000;
-                long nanoAdjustment = Integer.parseInt(value.substring(20)) * 1000l;
-                Timestamp timestamp = Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
-                return timestamp;
-            }
+            case TSDBConstants.TSDB_DATA_TYPE_TIMESTAMP:
+                return parseTimestampColumnData(row, colIndex);
             case TSDBConstants.TSDB_DATA_TYPE_BINARY:
                 return row.getString(colIndex) == null ? null : row.getString(colIndex).getBytes();
             case TSDBConstants.TSDB_DATA_TYPE_NCHAR:
@@ -197,7 +159,66 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         }
     }
 
-    public class Field {
+    private Timestamp parseTimestampColumnData(JSONArray row, int colIndex) throws SQLException {
+        if (row.get(colIndex) == null)
+            return null;
+        String tsFormatUpperCase = this.statement.getConnection().getClientInfo(TSDBDriver.PROPERTY_KEY_TIMESTAMP_FORMAT).toUpperCase();
+        TimestampFormat timestampFormat = TimestampFormat.valueOf(tsFormatUpperCase);
+        switch (timestampFormat) {
+            case TIMESTAMP: {
+                Long value = row.getLong(colIndex);
+                //TODO: this implementation has bug if the timestamp bigger than 9999_9999_9999_9
+                if (value < 1_0000_0000_0000_0L)
+                    return new Timestamp(value);
+                long epochSec = value / 1000_000L;
+                long nanoAdjustment = value % 1000_000L * 1000L;
+                return Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
+            }
+            case UTC: {
+                String value = row.getString(colIndex);
+                long epochSec = Timestamp.valueOf(value.substring(0, 19).replace("T", " ")).getTime() / 1000;
+                int fractionalSec = Integer.parseInt(value.substring(20, value.length() - 5));
+                long nanoAdjustment;
+                if (value.length() > 31) {
+                    // ns timestamp: yyyy-MM-ddTHH:mm:ss.SSSSSSSSS+0x00
+                    nanoAdjustment = fractionalSec;
+                } else if (value.length() > 28) {
+                    // ms timestamp: yyyy-MM-ddTHH:mm:ss.SSSSSS+0x00
+                    nanoAdjustment = fractionalSec * 1000L;
+                } else {
+                    // ms timestamp: yyyy-MM-ddTHH:mm:ss.SSS+0x00
+                    nanoAdjustment = fractionalSec * 1000_000L;
+                }
+                ZoneOffset zoneOffset = ZoneOffset.of(value.substring(value.length() - 5));
+                Instant instant = Instant.ofEpochSecond(epochSec, nanoAdjustment).atOffset(zoneOffset).toInstant();
+                return Timestamp.from(instant);
+            }
+            case STRING:
+            default: {
+                String value = row.getString(colIndex);
+                TimestampPrecision precision = Utils.guessTimestampPrecision(value);
+                if (precision == TimestampPrecision.MS) {
+                    // ms timestamp: yyyy-MM-dd HH:mm:ss.SSS
+                    return row.getTimestamp(colIndex);
+                }
+                if (precision == TimestampPrecision.US) {
+                    // us timestamp: yyyy-MM-dd HH:mm:ss.SSSSSS
+                    long epochSec = Timestamp.valueOf(value.substring(0, 19)).getTime() / 1000;
+                    long nanoAdjustment = Integer.parseInt(value.substring(20)) * 1000L;
+                    return Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
+                }
+                if (precision == TimestampPrecision.NS) {
+                    // ms timestamp: yyyy-MM-dd HH:mm:ss.SSSSSSSSS
+                    long epochSec = Timestamp.valueOf(value.substring(0, 19)).getTime() / 1000;
+                    long nanoAdjustment = Integer.parseInt(value.substring(20));
+                    return Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
+                }
+                throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNKNOWN_TIMESTAMP_PERCISION);
+            }
+        }
+    }
+
+    public static class Field {
         String name;
         int type;
         int length;
@@ -211,6 +232,7 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
             this.note = note;
             this.taos_type = taos_type;
         }
+
     }
 
     @Override
@@ -218,10 +240,7 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         if (isClosed())
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_RESULTSET_CLOSED);
         pos++;
-        if (pos <= resultSet.size() - 1) {
-            return true;
-        }
-        return false;
+        return pos <= resultSet.size() - 1;
     }
 
     @Override
@@ -231,13 +250,6 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         }
     }
 
-//    @Override
-//    public boolean wasNull() throws SQLException {
-//        if (isClosed())
-//            throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_RESULTSET_CLOSED);
-//        return resultSet.isEmpty();
-//    }
-
     @Override
     public String getString(int columnIndex) throws SQLException {
         checkAvailability(columnIndex, resultSet.get(pos).size());
@@ -262,7 +274,7 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         wasNull = false;
         if (value instanceof Boolean)
             return (boolean) value;
-        return Boolean.valueOf(value.toString());
+        return Boolean.parseBoolean(value.toString());
     }
 
     @Override
@@ -334,6 +346,7 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
             wasNull = true;
             return 0;
         }
+
         wasNull = false;
         if (value instanceof Timestamp) {
             return ((Timestamp) value).getTime();
@@ -416,9 +429,7 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
             return null;
         if (value instanceof Timestamp)
             return new Date(((Timestamp) value).getTime());
-        Date date = null;
-        date = Utils.parseDate(value.toString());
-        return date;
+        return Utils.parseDate(value.toString());
     }
 
     @Override
@@ -433,8 +444,7 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         Time time = null;
         try {
             time = Utils.parseTime(value.toString());
-        } catch (DateTimeParseException e) {
-            time = null;
+        } catch (DateTimeParseException ignored) {
         }
         return time;
     }
@@ -498,9 +508,9 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
             return null;
 
         if (value instanceof Long || value instanceof Integer || value instanceof Short || value instanceof Byte)
-            return new BigDecimal(Long.valueOf(value.toString()));
+            return new BigDecimal(Long.parseLong(value.toString()));
         if (value instanceof Double || value instanceof Float)
-            return new BigDecimal(Double.valueOf(value.toString()));
+            return BigDecimal.valueOf(Double.parseDouble(value.toString()));
         if (value instanceof Timestamp)
             return new BigDecimal(((Timestamp) value).getTime());
         BigDecimal ret;
@@ -610,36 +620,6 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         if (isClosed())
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_RESULTSET_CLOSED);
 
-//        if (this.resultSet.size() == 0)
-//            return false;
-//
-//        if (row == 0) {
-//            beforeFirst();
-//            return false;
-//        } else if (row == 1) {
-//            return first();
-//        } else if (row == -1) {
-//            return last();
-//        } else if (row > this.resultSet.size()) {
-//            afterLast();
-//            return false;
-//        } else {
-//            if (row < 0) {
-//                // adjust to reflect after end of result set
-//                int newRowPosition = this.resultSet.size() + row + 1;
-//                if (newRowPosition <= 0) {
-//                    beforeFirst();
-//                    return false;
-//                } else {
-//                    return absolute(newRowPosition);
-//                }
-//            } else {
-//                row--; // adjust for index difference
-//                this.pos = row;
-//                return true;
-//            }
-//        }
-
         throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_UNSUPPORTED_METHOD);
     }
 
@@ -683,5 +663,4 @@ public class RestfulResultSet extends AbstractResultSet implements ResultSet {
         return isClosed;
     }
 
-
-}
+}
\ No newline at end of file

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulResultSetMetaData.java

@@ -7,21 +7,20 @@ import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.sql.Types;
-import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 
 public class RestfulResultSetMetaData extends WrapperImpl implements ResultSetMetaData {
 
     private final String database;
-    private ArrayList<RestfulResultSet.Field> fields;
-    private final RestfulResultSet resultSet;
+    private final List<RestfulResultSet.Field> fields;
 
-    public RestfulResultSetMetaData(String database, ArrayList<RestfulResultSet.Field> fields, RestfulResultSet resultSet) {
+    public RestfulResultSetMetaData(String database, List<RestfulResultSet.Field> fields, RestfulResultSet resultSet) {
         this.database = database;
-        this.fields = fields;
-        this.resultSet = resultSet;
+        this.fields = fields == null ? Collections.emptyList() : fields;
     }
 
-    public ArrayList<RestfulResultSet.Field> getFields() {
+    public List<RestfulResultSet.Field> getFields() {
         return fields;
     }
 
@@ -139,8 +138,8 @@ public class RestfulResultSetMetaData extends WrapperImpl implements ResultSetMe
 
     @Override
     public String getColumnTypeName(int column) throws SQLException {
-        int taos_type = fields.get(column - 1).taos_type;
-        return TSDBConstants.taosType2JdbcTypeName(taos_type);
+        int taosType = fields.get(column - 1).taos_type;
+        return TSDBConstants.taosType2JdbcTypeName(taosType);
     }
 
     @Override

src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulStatement.java

@@ -35,10 +35,6 @@ public class RestfulStatement extends AbstractStatement {
         if (!SqlSyntaxValidator.isValidForExecuteQuery(sql))
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_FOR_EXECUTE_QUERY, "not a valid sql for executeQuery: " + sql);
 
-        if (SqlSyntaxValidator.isDatabaseUnspecifiedQuery(sql)) {
-            return executeOneQuery(sql);
-        }
-
         return executeOneQuery(sql);
     }
 
@@ -50,9 +46,6 @@ public class RestfulStatement extends AbstractStatement {
             throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_FOR_EXECUTE_UPDATE, "not a valid sql for executeUpdate: " + sql);
 
         final String url = "http://" + conn.getHost() + ":" + conn.getPort() + "/rest/sql";
-        if (SqlSyntaxValidator.isDatabaseUnspecifiedUpdate(sql)) {
-            return executeOneUpdate(url, sql);
-        }
 
         return executeOneUpdate(url, sql);
     }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/utils/HttpClientPoolUtil.java

@@ -9,6 +9,7 @@ import org.apache.http.client.protocol.HttpClientContext;
 import org.apache.http.conn.ConnectionKeepAliveStrategy;
 import org.apache.http.entity.StringEntity;
 import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
 import org.apache.http.message.BasicHeaderElementIterator;
@@ -16,31 +17,33 @@ import org.apache.http.protocol.HTTP;
 import org.apache.http.protocol.HttpContext;
 import org.apache.http.util.EntityUtils;
 
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 
 public class HttpClientPoolUtil {
 
     private static final String DEFAULT_CONTENT_TYPE = "application/json";
-    private static final String DEFAULT_TOKEN = "cm9vdDp0YW9zZGF0YQ==";
     private static final int DEFAULT_TIME_OUT = 15000;
     private static final int DEFAULT_MAX_PER_ROUTE = 32;
     private static final int DEFAULT_MAX_TOTAL = 1000;
     private static final int DEFAULT_HTTP_KEEP_TIME = 15000;
 
-    private static PoolingHttpClientConnectionManager connectionManager;
     private static CloseableHttpClient httpClient;
 
     private static synchronized void initPools() {
         if (httpClient == null) {
-            connectionManager = new PoolingHttpClientConnectionManager();
+            PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
             connectionManager.setDefaultMaxPerRoute(DEFAULT_MAX_PER_ROUTE);
             connectionManager.setMaxTotal(DEFAULT_MAX_TOTAL);
-            httpClient = HttpClients.custom().setKeepAliveStrategy(DEFAULT_KEEP_ALIVE_STRATEGY).setConnectionManager(connectionManager).build();
+            httpClient = HttpClients.custom()
+                    .setKeepAliveStrategy(DEFAULT_KEEP_ALIVE_STRATEGY)
+                    .setConnectionManager(connectionManager)
+                    .setRetryHandler(new DefaultHttpRequestRetryHandler(3, true))
+                    .build();
         }
     }
 
-    private static ConnectionKeepAliveStrategy DEFAULT_KEEP_ALIVE_STRATEGY = (response, context) -> {
+    private static final ConnectionKeepAliveStrategy DEFAULT_KEEP_ALIVE_STRATEGY = (response, context) -> {
         HeaderElementIterator it = new BasicHeaderElementIterator(response.headerIterator(HTTP.CONN_KEEP_ALIVE));
         int keepTime = DEFAULT_HTTP_KEEP_TIME * 1000;
         while (it.hasNext()) {
@@ -80,7 +83,7 @@ public class HttpClientPoolUtil {
             method.setHeader("Connection", "keep-alive");
             method.setHeader("Authorization", "Taosd " + token);
 
-            method.setEntity(new StringEntity(data, Charset.forName("UTF-8")));
+            method.setEntity(new StringEntity(data, StandardCharsets.UTF_8));
             HttpContext context = HttpClientContext.create();
             CloseableHttpResponse httpResponse = httpClient.execute(method, context);
             httpEntity = httpResponse.getEntity();
@@ -165,28 +168,18 @@ public class HttpClientPoolUtil {
             httpEntity = httpResponse.getEntity();
             if (httpEntity != null) {
                 responseBody = EntityUtils.toString(httpEntity, "UTF-8");
-//                logger.info("请求URL: " + uri + "+ 返回状态码：" + httpResponse.getStatusLine().getStatusCode());
             }
         } catch (Exception e) {
             if (method != null) {
                 method.abort();
             }
             e.printStackTrace();
-//            logger.error("execute get request exception, url:" + uri + ", exception:" + e.toString() + ",cost time(ms):"
-//                    + (System.currentTimeMillis() - startTime));
-            System.out.println("log:调用 HttpClientPoolUtil execute get request exception, url:" + uri + ", exception:" + e.toString() + ",cost time(ms):"
-                    + (System.currentTimeMillis() - startTime));
         } finally {
             if (httpEntity != null) {
                 try {
                     EntityUtils.consumeQuietly(httpEntity);
                 } catch (Exception e) {
-//                    e.printStackTrace();
-//                    logger.error("close response exception, url:" + uri + ", exception:" + e.toString()
-//                            + ",cost time(ms):" + (System.currentTimeMillis() - startTime));
-                    new Exception("close response exception, url:" + uri + ", exception:" + e.toString()
-                            + ",cost time(ms):" + (System.currentTimeMillis() - startTime))
-                            .printStackTrace();
+                    new Exception("close response exception, url:" + uri + ", exception:" + e.toString() + ",cost time(ms):" + (System.currentTimeMillis() - startTime)).printStackTrace();
                 }
             }
         }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/utils/OSUtils.java

@@ -4,14 +4,14 @@ public class OSUtils {
     private static final String OS = System.getProperty("os.name").toLowerCase();
 
     public static boolean isWindows() {
-        return OS.indexOf("win") >= 0;
+        return OS.contains("win");
     }
 
     public static boolean isMac() {
-        return OS.indexOf("mac") >= 0;
+        return OS.contains("mac");
     }
 
     public static boolean isLinux() {
-        return OS.indexOf("nux") >= 0;
+        return OS.contains("nux");
     }
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/utils/SqlSyntaxValidator.java

@@ -14,24 +14,14 @@
  *****************************************************************************/
 package com.taosdata.jdbc.utils;
 
-import com.taosdata.jdbc.TSDBConnection;
-
-import java.sql.Connection;
-
 public class SqlSyntaxValidator {
 
-    private static final String[] SQL = {"select", "insert", "import", "create", "use", "alter", "drop", "set", "show", "describe"};
+    private static final String[] SQL = {"select", "insert", "import", "create", "use", "alter", "drop", "set", "show", "describe", "reset"};
     private static final String[] updateSQL = {"insert", "import", "create", "use", "alter", "drop", "set"};
     private static final String[] querySQL = {"select", "show", "describe"};
 
     private static final String[] databaseUnspecifiedShow = {"databases", "dnodes", "mnodes", "variables"};
 
-    private TSDBConnection tsdbConnection;
-
-    public SqlSyntaxValidator(Connection connection) {
-        this.tsdbConnection = (TSDBConnection) connection;
-    }
-
     public static boolean isValidForExecuteUpdate(String sql) {
         for (String prefix : updateSQL) {
             if (sql.trim().toLowerCase().startsWith(prefix))
@@ -71,29 +61,11 @@ public class SqlSyntaxValidator {
 
     public static boolean isUseSql(String sql) {
         return sql.trim().toLowerCase().startsWith("use");
-//                || sql.trim().toLowerCase().matches("create\\s*database.*") || sql.toLowerCase().toLowerCase().matches("drop\\s*database.*");
-    }
-
-    public static boolean isShowSql(String sql) {
-        return sql.trim().toLowerCase().startsWith("show");
-    }
-
-    public static boolean isDescribeSql(String sql) {
-        return sql.trim().toLowerCase().startsWith("describe");
-    }
-
-
-    public static boolean isInsertSql(String sql) {
-        return sql.trim().toLowerCase().startsWith("insert") || sql.trim().toLowerCase().startsWith("import");
     }
 
     public static boolean isSelectSql(String sql) {
         return sql.trim().toLowerCase().startsWith("select");
     }
 
-    public static boolean isShowDatabaseSql(String sql) {
-        return sql.trim().toLowerCase().matches("show\\s*databases");
-    }
-
 
 }

src/connector/jdbc/src/main/java/com/taosdata/jdbc/utils/TaosInfo.java

@@ -7,9 +7,9 @@ import java.util.concurrent.atomic.AtomicLong;
 public class TaosInfo implements TaosInfoMBean {
 
     private static volatile TaosInfo instance;
-    private AtomicLong connect_open = new AtomicLong();
-    private AtomicLong connect_close = new AtomicLong();
-    private AtomicLong statement_count = new AtomicLong();
+    private final AtomicLong connect_open = new AtomicLong();
+    private final AtomicLong connect_close = new AtomicLong();
+    private final AtomicLong statement_count = new AtomicLong();
 
     static {
         try {

src/connector/jdbc/src/main/java/com/taosdata/jdbc/utils/Utils.java

@@ -3,14 +3,13 @@ package com.taosdata.jdbc.utils;
 import com.google.common.collect.Range;
 import com.google.common.collect.RangeSet;
 import com.google.common.collect.TreeRangeSet;
+import com.taosdata.jdbc.enums.TimestampPrecision;
 
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.sql.Date;
 import java.sql.Time;
 import java.sql.Timestamp;
-import java.time.LocalDate;
 import java.time.LocalDateTime;
-import java.time.LocalTime;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeFormatterBuilder;
 import java.time.format.DateTimeParseException;
@@ -23,46 +22,58 @@ import java.util.stream.IntStream;
 
 public class Utils {
 
-    private static Pattern ptn = Pattern.compile(".*?'");
-
-    private static final DateTimeFormatter formatter = new DateTimeFormatterBuilder()
-            .appendPattern("yyyy-MM-dd HH:mm:ss.SSS").toFormatter();
-    private static final DateTimeFormatter formatter2 = new DateTimeFormatterBuilder()
-            .appendPattern("yyyy-MM-dd HH:mm:ss.SSSSSS").toFormatter();
+    private static final Pattern ptn = Pattern.compile(".*?'");
+    private static final DateTimeFormatter milliSecFormatter = new DateTimeFormatterBuilder().appendPattern("yyyy-MM-dd HH:mm:ss.SSS").toFormatter();
+    private static final DateTimeFormatter microSecFormatter = new DateTimeFormatterBuilder().appendPattern("yyyy-MM-dd HH:mm:ss.SSSSSS").toFormatter();
+    private static final DateTimeFormatter nanoSecFormatter = new DateTimeFormatterBuilder().appendPattern("yyyy-MM-dd HH:mm:ss.SSSSSSSSS").toFormatter();
 
     public static Time parseTime(String timestampStr) throws DateTimeParseException {
-        LocalTime time;
-        try {
-            time = LocalTime.parse(timestampStr, formatter);
-        } catch (DateTimeParseException e) {
-            time = LocalTime.parse(timestampStr, formatter2);
-        }
-        return Time.valueOf(time);
+        LocalDateTime dateTime = parseLocalDateTime(timestampStr);
+        return dateTime != null ? Time.valueOf(dateTime.toLocalTime()) : null;
     }
 
-    public static Date parseDate(String timestampStr) throws DateTimeParseException {
-        LocalDate date;
-        try {
-            date = LocalDate.parse(timestampStr, formatter);
-        } catch (DateTimeParseException e) {
-            date = LocalDate.parse(timestampStr, formatter2);
-        }
-        return Date.valueOf(date);
+    public static Date parseDate(String timestampStr) {
+        LocalDateTime dateTime = parseLocalDateTime(timestampStr);
+        return dateTime != null ? Date.valueOf(String.valueOf(dateTime)) : null;
     }
 
     public static Timestamp parseTimestamp(String timeStampStr) {
-        LocalDateTime dateTime;
+        LocalDateTime dateTime = parseLocalDateTime(timeStampStr);
+        return dateTime != null ? Timestamp.valueOf(dateTime) : null;
+    }
+
+    private static LocalDateTime parseLocalDateTime(String timeStampStr) {
         try {
-            dateTime = LocalDateTime.parse(timeStampStr, formatter);
+            return parseMilliSecTimestamp(timeStampStr);
         } catch (DateTimeParseException e) {
-            dateTime = LocalDateTime.parse(timeStampStr, formatter2);
+            try {
+                return parseMicroSecTimestamp(timeStampStr);
+            } catch (DateTimeParseException ee) {
+                try {
+                    return parseNanoSecTimestamp(timeStampStr);
+                } catch (DateTimeParseException eee) {
+                    eee.printStackTrace();
+                }
+            }
         }
-        return Timestamp.valueOf(dateTime);
+        return null;
+    }
+
+    private static LocalDateTime parseMilliSecTimestamp(String timeStampStr) throws DateTimeParseException {
+        return LocalDateTime.parse(timeStampStr, milliSecFormatter);
+    }
+
+    private static LocalDateTime parseMicroSecTimestamp(String timeStampStr) throws DateTimeParseException {
+        return LocalDateTime.parse(timeStampStr, microSecFormatter);
+    }
+
+    private static LocalDateTime parseNanoSecTimestamp(String timeStampStr) throws DateTimeParseException {
+        return LocalDateTime.parse(timeStampStr, nanoSecFormatter);
     }
 
     public static String escapeSingleQuota(String origin) {
         Matcher m = ptn.matcher(origin);
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         int end = 0;
         while (m.find()) {
             end = m.end();
@@ -75,7 +86,7 @@ public class Utils {
                     sb.append(seg);
                 }
             } else { // len > 1
-                sb.append(seg.substring(0, seg.length() - 2));
+                sb.append(seg, 0, seg.length() - 2);
                 char lastcSec = seg.charAt(seg.length() - 2);
                 if (lastcSec == '\\') {
                     sb.append("\\'");
@@ -93,17 +104,31 @@ public class Utils {
     }
 
     public static String getNativeSql(String rawSql, Object[] parameters) {
+        if (parameters == null || !rawSql.contains("?"))
+            return rawSql;
         // toLowerCase
         String preparedSql = rawSql.trim().toLowerCase();
-        String[] clause = new String[]{"values\\s*\\(.*?\\)", "tags\\s*\\(.*?\\)", "where\\s*.*"};
+        String[] clause = new String[]{"tags\\s*\\([\\s\\S]*?\\)", "where[\\s\\S]*"};
         Map<Integer, Integer> placeholderPositions = new HashMap<>();
         RangeSet<Integer> clauseRangeSet = TreeRangeSet.create();
         findPlaceholderPosition(preparedSql, placeholderPositions);
+        // find tags and where clause's position
         findClauseRangeSet(preparedSql, clause, clauseRangeSet);
+        // find values clause's position
+        findValuesClauseRangeSet(preparedSql, clauseRangeSet);
 
         return transformSql(rawSql, parameters, placeholderPositions, clauseRangeSet);
     }
 
+    private static void findValuesClauseRangeSet(String preparedSql, RangeSet<Integer> clauseRangeSet) {
+        Matcher matcher = Pattern.compile("(values|,)\\s*(\\([^)]*\\))").matcher(preparedSql);
+        while (matcher.find()) {
+            int start = matcher.start(2);
+            int end = matcher.end(2);
+            clauseRangeSet.add(Range.closedOpen(start, end));
+        }
+    }
+
     private static void findClauseRangeSet(String preparedSql, String[] regexArr, RangeSet<Integer> clauseRangeSet) {
         clauseRangeSet.clear();
         for (String regex : regexArr) {
@@ -111,7 +136,7 @@ public class Utils {
             while (matcher.find()) {
                 int start = matcher.start();
                 int end = matcher.end();
-                clauseRangeSet.add(Range.closed(start, end));
+                clauseRangeSet.add(Range.closedOpen(start, end));
             }
         }
     }
@@ -146,7 +171,7 @@ public class Utils {
             String paraStr;
             if (para != null) {
                 if (para instanceof byte[]) {
-                    paraStr = new String((byte[]) para, Charset.forName("UTF-8"));
+                    paraStr = new String((byte[]) para, StandardCharsets.UTF_8);
                 } else {
                     paraStr = para.toString();
                 }
@@ -167,13 +192,47 @@ public class Utils {
         }).collect(Collectors.joining());
     }
 
-
     public static String formatTimestamp(Timestamp timestamp) {
         int nanos = timestamp.getNanos();
-        if (nanos % 1000000l != 0)
-            return timestamp.toLocalDateTime().format(formatter2);
-        return timestamp.toLocalDateTime().format(formatter);
+        if (nanos % 1000000L != 0)
+            return timestamp.toLocalDateTime().format(microSecFormatter);
+        return timestamp.toLocalDateTime().format(milliSecFormatter);
+    }
+
+    public static TimestampPrecision guessTimestampPrecision(String value) {
+        if (isMilliSecFormat(value))
+            return TimestampPrecision.MS;
+        if (isMicroSecFormat(value))
+            return TimestampPrecision.US;
+        if (isNanoSecFormat(value))
+            return TimestampPrecision.NS;
+        return TimestampPrecision.UNKNOWN;
+    }
+
+    private static boolean isMilliSecFormat(String timestampStr) {
+        try {
+            milliSecFormatter.parse(timestampStr);
+        } catch (DateTimeParseException e) {
+            return false;
+        }
+        return true;
     }
 
+    private static boolean isMicroSecFormat(String timestampStr) {
+        try {
+            microSecFormatter.parse(timestampStr);
+        } catch (DateTimeParseException e) {
+            return false;
+        }
+        return true;
+    }
 
+    private static boolean isNanoSecFormat(String timestampStr) {
+        try {
+            nanoSecFormatter.parse(timestampStr);
+        } catch (DateTimeParseException e) {
+            return false;
+        }
+        return true;
+    }
 }

src/connector/jdbc/src/test/java/com/taosdata/jdbc/StatementTest.java

-package com.taosdata.jdbc;
-
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.BeforeClass;
-import org.junit.Test;
-
-import java.sql.*;
-import java.util.Properties;
-
-public class StatementTest {
-    static Connection connection = null;
-    static Statement statement = null;
-    static String dbName = "test";
-    static String tName = "t0";
-    static String host = "localhost";
-
-    @BeforeClass
-    public static void createConnection() throws SQLException {
-        try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
-            Properties properties = new Properties();
-            properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
-            properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
-            properties.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
-            connection = DriverManager.getConnection("jdbc:TAOS://" + host + ":0/?user=root&password=taosdata", properties);
-            statement = connection.createStatement();
-            statement.executeUpdate("drop database if exists " + dbName);
-
-        } catch (ClassNotFoundException e) {
-            return;
-        }
-    }
-
-    @Test
-    public void testCase() {
-        try {
-            ResultSet rs = statement.executeQuery("show databases");
-            ResultSetMetaData metaData = rs.getMetaData();
-            while (rs.next()) {
-                for (int i = 1; i <= metaData.getColumnCount(); i++) {
-                    System.out.print(metaData.getColumnLabel(i) + ":" + rs.getString(i) + "\t");
-                }
-                System.out.println();
-            }
-        } catch (SQLException e) {
-            e.printStackTrace();
-        }
-    }
-
-    @Test
-    public void createTableAndQuery() throws SQLException {
-        long ts = System.currentTimeMillis();
-
-        statement.executeUpdate("create database if not exists " + dbName);
-        statement.executeUpdate("create table if not exists " + dbName + "." + tName + "(ts timestamp, k1 int)");
-        statement.executeUpdate("insert into " + dbName + "." + tName + " values (" + ts + ", 1)");
-        statement.execute("select * from " + dbName + "." + tName);
-        ResultSet resultSet = statement.getResultSet();
-        Assert.assertNotNull(resultSet);
-
-        boolean isClosed = statement.isClosed();
-        Assert.assertEquals(false, isClosed);
-    }
-
-    @Test(expected = SQLException.class)
-    public void testUnsupport() throws SQLException {
-        Assert.assertNotNull(statement.unwrap(TSDBStatement.class));
-        Assert.assertTrue(statement.isWrapperFor(TSDBStatement.class));
-
-        statement.getMaxFieldSize();
-        statement.setMaxFieldSize(0);
-        statement.setEscapeProcessing(true);
-        statement.cancel();
-        statement.getWarnings();
-        statement.clearWarnings();
-        statement.setCursorName(null);
-        statement.getMoreResults();
-        statement.setFetchDirection(0);
-        statement.getFetchDirection();
-        statement.getResultSetConcurrency();
-        statement.getResultSetType();
-        statement.getConnection();
-        statement.getMoreResults();
-        statement.getGeneratedKeys();
-        statement.executeUpdate(null, 0);
-        statement.executeUpdate(null, new int[]{0});
-        statement.executeUpdate(null, new String[]{"str1", "str2"});
-        statement.getResultSetHoldability();
-        statement.setPoolable(true);
-        statement.isPoolable();
-        statement.closeOnCompletion();
-        statement.isCloseOnCompletion();
-    }
-
-    @AfterClass
-    public static void close() {
-        try {
-            statement.execute("drop database if exists " + dbName);
-            if (statement != null)
-                statement.close();
-            if (connection != null)
-                connection.close();
-        } catch (SQLException e) {
-            e.printStackTrace();
-        }
-    }
-}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBConnectionTest.java

@@ -5,7 +5,6 @@ import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
-import javax.management.OperationsException;
 import java.sql.*;
 import java.util.Properties;
 
@@ -380,14 +379,15 @@ public class TSDBConnectionTest {
         conn.abort(null);
     }
 
-    @Test(expected = SQLFeatureNotSupportedException.class)
+    @Test
     public void setNetworkTimeout() throws SQLException {
         conn.setNetworkTimeout(null, 1000);
     }
 
-    @Test(expected = SQLFeatureNotSupportedException.class)
+    @Test
     public void getNetworkTimeout() throws SQLException {
-        conn.getNetworkTimeout();
+        int networkTimeout = conn.getNetworkTimeout();
+        Assert.assertEquals(0, networkTimeout);
     }
 
     @Test

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBJNIConnectorTest.java

@@ -2,11 +2,16 @@ package com.taosdata.jdbc;
 
 import org.junit.Test;
 
+import java.lang.management.ManagementFactory;
+import java.lang.management.RuntimeMXBean;
 import java.sql.SQLException;
 import java.sql.SQLWarning;
 import java.util.ArrayList;
 import java.util.List;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
 public class TSDBJNIConnectorTest {
 
     private static TSDBResultSetRowData rowData;
@@ -14,17 +19,68 @@ public class TSDBJNIConnectorTest {
     @Test
     public void test() {
         try {
+
+            try {
+                //change sleepSeconds when debugging with attach to process to find PID
+                int sleepSeconds = -1;
+                if (sleepSeconds>0) {
+                    RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean();
+                    String jvmName = runtimeBean.getName();
+                    long pid = Long.valueOf(jvmName.split("@")[0]);
+                    System.out.println("JVM PID  = " + pid);
+
+                    Thread.sleep(sleepSeconds*1000);
+                }
+            }
+            catch (Exception e) {
+                e.printStackTrace();
+            }
+
             // init
-            TSDBJNIConnector.init("/etc/taos/taos.cfg", null, null, null);
+            TSDBJNIConnector.init("/etc/taos", null, null, null);
+
             // connect
             TSDBJNIConnector connector = new TSDBJNIConnector();
-            connector.connect("127.0.0.1", 6030, "unsign_jni", "root", "taosdata");
+            connector.connect("127.0.0.1", 6030, null, "root", "taosdata");
+
+            // setup
+            String setupSqlStrs[] = {"create database if not exists d precision \"us\"",
+                                      "create table if not exists d.t(ts timestamp, f int)",
+                                      "create database if not exists d2",
+                                      "create table if not exists d2.t2(ts timestamp, f int)",
+                                      "insert into d.t values(now+100s, 100)",
+                                      "insert into d2.t2 values(now+200s, 200)"
+                                      };
+            for (String setupSqlStr : setupSqlStrs) {
+                long setupSql = connector.executeQuery(setupSqlStr);
+
+                assertEquals(0, connector.getResultTimePrecision(setupSql));
+                if (connector.isUpdateQuery(setupSql)) {
+                    connector.freeResultSet(setupSql);
+                }
+            }
+
+            {
+                long sqlObj1 = connector.executeQuery("select * from d2.t2");
+                assertEquals(0, connector.getResultTimePrecision(sqlObj1));
+                List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
+                int code = connector.getSchemaMetaData(sqlObj1, columnMetaDataList);
+                rowData = new TSDBResultSetRowData(columnMetaDataList.size());
+                assertTrue(next(connector, sqlObj1));
+                assertEquals(0, connector.getResultTimePrecision(sqlObj1));
+                connector.freeResultSet(sqlObj1);
+            }
+
             // executeQuery
-            long pSql = connector.executeQuery("select * from unsign_jni.us_table");
+            long pSql = connector.executeQuery("select * from d.t");
+
             if (connector.isUpdateQuery(pSql)) {
                 connector.freeResultSet(pSql);
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_INVALID_WITH_EXECUTEQUERY);
             }
+
+            assertEquals(1, connector.getResultTimePrecision(pSql));
+
             // get schema
             List<ColumnMetaData> columnMetaDataList = new ArrayList<>();
             int code = connector.getSchemaMetaData(pSql, columnMetaDataList);
@@ -37,6 +93,8 @@ public class TSDBJNIConnectorTest {
             if (code == TSDBConstants.JNI_NUM_OF_FIELDS_0) {
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_NUM_OF_FIELDS_0);
             }
+
+            assertEquals(1, connector.getResultTimePrecision(pSql));
             int columnSize = columnMetaDataList.size();
             // print metadata
             for (int i = 0; i < columnSize; i++) {
@@ -45,9 +103,8 @@ public class TSDBJNIConnectorTest {
             rowData = new TSDBResultSetRowData(columnSize);
             // iterate resultSet
             for (int i = 0; next(connector, pSql); i++) {
-//                System.out.println("col[" + i + "] size: " + rowData.getColSize());
-//                rowData.getData().stream().forEach(col -> System.out.print(col + "\t"));
-//                System.out.println();
+                assertEquals(1, connector.getResultTimePrecision(pSql));
+                System.out.println();
             }
             // close resultSet
             code = connector.freeResultSet(pSql);
@@ -57,6 +114,10 @@ public class TSDBJNIConnectorTest {
                 throw TSDBError.createSQLException(TSDBErrorNumbers.ERROR_JNI_RESULT_SET_NULL);
             }
             // close statement
+            connector.executeQuery("use d");
+            String[] lines = new String[] {"st,t1=3i64,t2=4f64,t3=\"t3\" c1=3i64,c3=L\"passit\",c2=false,c4=4f64 1626006833639000000ns",
+                                           "st,t1=4i64,t3=\"t4\",t2=5f64,t4=5f64 c1=3i64,c3=L\"passitagin\",c2=true,c4=5f64,c5=5f64 1626006833640000000ns"};
+            connector.insertLines(lines);
 
             // close connection
             connector.closeConnection();
@@ -86,4 +147,4 @@ public class TSDBJNIConnectorTest {
         }
     }
 
-}
\ No newline at end of file
+}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBParameterMetaDataTest.java

 package com.taosdata.jdbc;
 
-import com.taosdata.jdbc.rs.RestfulParameterMetaData;
 import org.junit.AfterClass;
 import org.junit.Assert;
 import org.junit.BeforeClass;

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBPreparedStatementTest.java

@@ -2,7 +2,6 @@ package com.taosdata.jdbc;
 
 import org.junit.*;
 
-import java.io.IOException;
 import java.math.BigDecimal;
 import java.sql.*;
 import java.util.ArrayList;
@@ -14,6 +13,7 @@ public class TSDBPreparedStatementTest {
     private static Connection conn;
     private static final String sql_insert = "insert into t1 values(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
     private static final String sql_select = "select * from t1 where ts >= ? and ts < ? and f1 >= ?";
+    private static final String dbname = "test_pstmt_jni";
 
     private PreparedStatement pstmt_insert;
     private PreparedStatement pstmt_select;
@@ -25,7 +25,7 @@ public class TSDBPreparedStatementTest {
         long ts = System.currentTimeMillis();
         pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setInt(2, 2);
-        pstmt_insert.setLong(3, 3l);
+        pstmt_insert.setLong(3, 3L);
         pstmt_insert.setFloat(4, 3.14f);
         pstmt_insert.setDouble(5, 3.1415);
         pstmt_insert.setShort(6, (short) 6);
@@ -52,8 +52,8 @@ public class TSDBPreparedStatementTest {
             Assert.assertEquals(ts, rs.getTimestamp(1).getTime());
             Assert.assertEquals(2, rs.getInt(2));
             Assert.assertEquals(2, rs.getInt("f1"));
-            Assert.assertEquals(3l, rs.getLong(3));
-            Assert.assertEquals(3l, rs.getLong("f2"));
+            Assert.assertEquals(3L, rs.getLong(3));
+            Assert.assertEquals(3L, rs.getLong("f2"));
             Assert.assertEquals(3.14f, rs.getFloat(4), 0.0);
             Assert.assertEquals(3.14f, rs.getFloat("f3"), 0.0);
             Assert.assertEquals(3.1415, rs.getDouble(5), 0.0);
@@ -296,7 +296,306 @@ public class TSDBPreparedStatementTest {
             assertAllNullExceptTimestamp(rs, ts);
         }
     }
-    
+
+    /*
+    @Test
+    public void executeTest() throws SQLException {
+        Statement stmt = conn.createStatement();
+
+        int numOfRows = 1000;
+
+        for (int loop = 0; loop < 10; loop++) {
+            stmt.execute("drop table if exists weather_test");
+            stmt.execute("create table weather_test(ts timestamp, f1 nchar(4), f2 float, f3 double, f4 timestamp, f5 int, f6 bool, f7 binary(10))");
+
+            TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? values(?, ?, ?, ?, ?, ?, ?, ?)");
+            Random r = new Random();
+            s.setTableName("weather_test");
+
+            ArrayList<Long> ts = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                ts.add(System.currentTimeMillis() + i);
+            }
+            s.setTimestamp(0, ts);
+
+            int random = 10 + r.nextInt(5);
+            ArrayList<String> s2 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    s2.add(null);
+                } else {
+                    s2.add("分支" + i % 4);
+                }
+            }
+            s.setNString(1, s2, 4);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<Float> s3 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    s3.add(null);
+                } else {
+                    s3.add(r.nextFloat());
+                }
+            }
+            s.setFloat(2, s3);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<Double> s4 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    s4.add(null);
+                } else {
+                    s4.add(r.nextDouble());
+                }
+            }
+            s.setDouble(3, s4);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<Long> ts2 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    ts2.add(null);
+                } else {
+                    ts2.add(System.currentTimeMillis() + i);
+                }
+            }
+            s.setTimestamp(4, ts2);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<Integer> vals = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    vals.add(null);
+                } else {
+                    vals.add(r.nextInt());
+                }
+            }
+            s.setInt(5, vals);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<Boolean> sb = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    sb.add(null);
+                } else {
+                    sb.add(i % 2 == 0);
+                }
+            }
+            s.setBoolean(6, sb);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<String> s5 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    s5.add(null);
+                } else {
+                    s5.add("test" + i % 10);
+                }
+            }
+            s.setString(7, s5, 10);
+
+            s.columnDataAddBatch();
+            s.columnDataExecuteBatch();
+            s.columnDataCloseBatch();
+
+            String sql = "select * from weather_test";
+            PreparedStatement statement = conn.prepareStatement(sql);
+            ResultSet rs = statement.executeQuery();
+            int rows = 0;
+            while (rs.next()) {
+                rows++;
+            }
+            Assert.assertEquals(numOfRows, rows);
+        }
+    }
+
+    @Test
+    public void bindDataSelectColumnTest() throws SQLException {
+        Statement stmt = conn.createStatement();
+
+        int numOfRows = 1000;
+
+        for (int loop = 0; loop < 10; loop++) {
+            stmt.execute("drop table if exists weather_test");
+            stmt.execute("create table weather_test(ts timestamp, f1 nchar(4), f2 float, f3 double, f4 timestamp, f5 int, f6 bool, f7 binary(10))");
+
+            TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? (ts, f1, f7) values(?, ?, ?)");
+            Random r = new Random();
+            s.setTableName("weather_test");
+
+            ArrayList<Long> ts = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                ts.add(System.currentTimeMillis() + i);
+            }
+            s.setTimestamp(0, ts);
+
+            int random = 10 + r.nextInt(5);
+            ArrayList<String> s2 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    s2.add(null);
+                } else {
+                    s2.add("分支" + i % 4);
+                }
+            }
+            s.setNString(1, s2, 4);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<String> s3 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                if (i % random == 0) {
+                    s3.add(null);
+                } else {
+                    s3.add("test" + i % 10);
+                }
+            }
+            s.setString(2, s3, 10);
+
+            s.columnDataAddBatch();
+            s.columnDataExecuteBatch();
+            s.columnDataCloseBatch();
+
+            String sql = "select * from weather_test";
+            PreparedStatement statement = conn.prepareStatement(sql);
+            ResultSet rs = statement.executeQuery();
+            int rows = 0;
+            while (rs.next()) {
+                rows++;
+            }
+            Assert.assertEquals(numOfRows, rows);
+        }
+    }
+
+    @Test
+    public void bindDataWithSingleTagTest() throws SQLException {
+        Statement stmt = conn.createStatement();
+
+        String[] types = new String[]{"tinyint", "smallint", "int", "bigint", "bool", "float", "double", "binary(10)", "nchar(10)"};
+
+        for (String type : types) {
+            stmt.execute("drop table if exists weather_test");
+            stmt.execute("create table weather_test(ts timestamp, f1 nchar(10), f2 binary(10)) tags (t " + type + ")");
+
+            int numOfRows = 1;
+
+            TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? using weather_test tags(?) values(?, ?, ?)");
+            Random r = new Random();
+            s.setTableName("w1");
+
+            switch (type) {
+                case "tinyint":
+                case "smallint":
+                case "int":
+                case "bigint":
+                    s.setTagInt(0, 1);
+                    break;
+                case "float":
+                    s.setTagFloat(0, 1.23f);
+                    break;
+                case "double":
+                    s.setTagDouble(0, 3.14159265);
+                    break;
+                case "bool":
+                    s.setTagBoolean(0, true);
+                    break;
+                case "binary(10)":
+                    s.setTagString(0, "test");
+                    break;
+                case "nchar(10)":
+                    s.setTagNString(0, "test");
+                    break;
+                default:
+                    break;
+            }
+
+
+            ArrayList<Long> ts = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                ts.add(System.currentTimeMillis() + i);
+            }
+            s.setTimestamp(0, ts);
+
+            int random = 10 + r.nextInt(5);
+            ArrayList<String> s2 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                s2.add("分支" + i % 4);
+            }
+            s.setNString(1, s2, 10);
+
+            random = 10 + r.nextInt(5);
+            ArrayList<String> s3 = new ArrayList<>();
+            for (int i = 0; i < numOfRows; i++) {
+                s3.add("test" + i % 4);
+            }
+            s.setString(2, s3, 10);
+
+            s.columnDataAddBatch();
+            s.columnDataExecuteBatch();
+            s.columnDataCloseBatch();
+
+            String sql = "select * from weather_test";
+            PreparedStatement statement = conn.prepareStatement(sql);
+            ResultSet rs = statement.executeQuery();
+            int rows = 0;
+            while (rs.next()) {
+                rows++;
+            }
+            Assert.assertEquals(numOfRows, rows);
+        }
+    }
+
+
+    @Test
+    public void bindDataWithMultipleTagsTest() throws SQLException {
+        Statement stmt = conn.createStatement();
+
+        stmt.execute("drop table if exists weather_test");
+        stmt.execute("create table weather_test(ts timestamp, f1 nchar(10), f2 binary(10)) tags (t1 int, t2 binary(10))");
+
+        int numOfRows = 1;
+
+        TSDBPreparedStatement s = (TSDBPreparedStatement) conn.prepareStatement("insert into ? using weather_test tags(?,?) (ts, f2) values(?, ?)");
+        s.setTableName("w2");
+        s.setTagInt(0, 1);
+        s.setTagString(1, "test");
+
+
+        ArrayList<Long> ts = new ArrayList<>();
+        for (int i = 0; i < numOfRows; i++) {
+            ts.add(System.currentTimeMillis() + i);
+        }
+        s.setTimestamp(0, ts);
+
+        ArrayList<String> s2 = new ArrayList<>();
+        for (int i = 0; i < numOfRows; i++) {
+            s2.add("test" + i % 4);
+        }
+        s.setString(1, s2, 10);
+
+        s.columnDataAddBatch();
+        s.columnDataExecuteBatch();
+        s.columnDataCloseBatch();
+
+        String sql = "select * from weather_test";
+        PreparedStatement statement = conn.prepareStatement(sql);
+        ResultSet rs = statement.executeQuery();
+        int rows = 0;
+        while (rs.next()) {
+            rows++;
+        }
+        Assert.assertEquals(numOfRows, rows);
+    }
+     */
+
+    @Test(expected = SQLException.class)
+    public void createTwoSameDbTest() throws SQLException {
+        // when
+        Statement stmt = conn.createStatement();
+        stmt.execute("create database dbtest");
+        stmt.execute("create database dbtest");
+    }
+
     @Test
     public void setBoolean() throws SQLException {
         // given
@@ -490,7 +789,7 @@ public class TSDBPreparedStatementTest {
     public void setBigDecimal() throws SQLException {
         // given
         long ts = System.currentTimeMillis();
-        BigDecimal bigDecimal = new BigDecimal(3.14444);
+        BigDecimal bigDecimal = new BigDecimal("3.14444");
 
         // when
         pstmt_insert.setTimestamp(1, new Timestamp(ts));
@@ -543,13 +842,13 @@ public class TSDBPreparedStatementTest {
     }
 
     @Test
-    public void setBytes() throws SQLException, IOException {
+    public void setBytes() throws SQLException {
         // given
         long ts = System.currentTimeMillis();
         byte[] f8 = "{\"name\": \"john\", \"age\": 10, \"address\": \"192.168.1.100\"}".getBytes();
 
         // when
-        pstmt_insert.setTimestamp(1, new Timestamp(System.currentTimeMillis()));
+        pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setBytes(9, f8);
         int result = pstmt_insert.executeUpdate();
 
@@ -701,7 +1000,7 @@ public class TSDBPreparedStatementTest {
         long ts = System.currentTimeMillis();
         pstmt_insert.setTimestamp(1, new Timestamp(ts));
         pstmt_insert.setInt(2, 2);
-        pstmt_insert.setLong(3, 3l);
+        pstmt_insert.setLong(3, 3L);
         pstmt_insert.setFloat(4, 3.14f);
         pstmt_insert.setDouble(5, 3.1415);
         pstmt_insert.setShort(6, (short) 6);
@@ -798,9 +1097,9 @@ public class TSDBPreparedStatementTest {
         try {
             conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
             try (Statement stmt = conn.createStatement()) {
-                stmt.execute("drop database if exists test_pstmt_jni");
-                stmt.execute("create database if not exists test_pstmt_jni");
-                stmt.execute("use test_pstmt_jni");
+                stmt.execute("drop database if exists " + dbname);
+                stmt.execute("create database if not exists " + dbname);
+                stmt.execute("use " + dbname);
             }
         } catch (SQLException e) {
             e.printStackTrace();
@@ -810,6 +1109,9 @@ public class TSDBPreparedStatementTest {
     @AfterClass
     public static void afterClass() {
         try {
+            Statement statement = conn.createStatement();
+            statement.execute("drop database if exists " + dbname);
+            statement.close();
             if (conn != null)
                 conn.close();
         } catch (SQLException e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBResultSetTest.java

@@ -95,13 +95,13 @@ public class TSDBResultSetTest {
     @Test
     public void getBigDecimal() throws SQLException {
         BigDecimal f1 = rs.getBigDecimal("f1");
-        Assert.assertEquals(1609430400000l, f1.longValue());
+        Assert.assertEquals(1609430400000L, f1.longValue());
 
         BigDecimal f2 = rs.getBigDecimal("f2");
         Assert.assertEquals(1, f2.intValue());
 
         BigDecimal f3 = rs.getBigDecimal("f3");
-        Assert.assertEquals(100l, f3.longValue());
+        Assert.assertEquals(100L, f3.longValue());
 
         BigDecimal f4 = rs.getBigDecimal("f4");
         Assert.assertEquals(3.1415f, f4.floatValue(), 0.00000f);
@@ -125,13 +125,13 @@ public class TSDBResultSetTest {
         Assert.assertEquals(1, Ints.fromByteArray(f2));
 
         byte[] f3 = rs.getBytes("f3");
-        Assert.assertEquals(100l, Longs.fromByteArray(f3));
+        Assert.assertEquals(100L, Longs.fromByteArray(f3));
 
         byte[] f4 = rs.getBytes("f4");
-        Assert.assertEquals(3.1415f, Float.valueOf(new String(f4)), 0.000000f);
+        Assert.assertEquals(3.1415f, Float.parseFloat(new String(f4)), 0.000000f);
 
         byte[] f5 = rs.getBytes("f5");
-        Assert.assertEquals(3.1415926, Double.valueOf(new String(f5)), 0.000000f);
+        Assert.assertEquals(3.1415926, Double.parseDouble(new String(f5)), 0.000000f);
 
         byte[] f6 = rs.getBytes("f6");
         Assert.assertTrue(Arrays.equals("abc".getBytes(), f6));
@@ -223,7 +223,7 @@ public class TSDBResultSetTest {
 
         Object f3 = rs.getObject("f3");
         Assert.assertEquals(Long.class, f3.getClass());
-        Assert.assertEquals(100l, f3);
+        Assert.assertEquals(100L, f3);
 
         Object f4 = rs.getObject("f4");
         Assert.assertEquals(Float.class, f4.getClass());
@@ -421,7 +421,7 @@ public class TSDBResultSetTest {
 
     @Test(expected = SQLFeatureNotSupportedException.class)
     public void updateLong() throws SQLException {
-        rs.updateLong(1, 1l);
+        rs.updateLong(1, 1L);
     }
 
     @Test(expected = SQLFeatureNotSupportedException.class)

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBStatementTest.java

@@ -14,24 +14,6 @@ public class TSDBStatementTest {
     private static Connection conn;
     private static Statement stmt;
 
-    @Test
-    public void executeQuery() {
-        try {
-            ResultSet rs = stmt.executeQuery("show databases");
-            Assert.assertNotNull(rs);
-            ResultSetMetaData meta = rs.getMetaData();
-            while (rs.next()) {
-                for (int i = 1; i <= meta.getColumnCount(); i++) {
-                    System.out.print(meta.getColumnLabel(i) + ": " + rs.getString(i) + "\t");
-                }
-                System.out.println();
-            }
-            rs.close();
-        } catch (SQLException e) {
-            e.printStackTrace();
-        }
-    }
-
     @Test
     public void executeUpdate() {
         final String dbName = ("test_" + UUID.randomUUID()).replace("-", "_").substring(0, 32);
@@ -173,10 +155,6 @@ public class TSDBStatementTest {
             Assert.assertEquals(3, meta.getColumnCount());
             int count = 0;
             while (rs.next()) {
-                for (int i = 1; i <= meta.getColumnCount(); i++) {
-                    System.out.print(meta.getColumnLabel(i) + ": " + rs.getString(i) + "\t");
-                }
-                System.out.println();
                 count++;
             }
             Assert.assertEquals(1, count);

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/AppMemoryLeakTest.java

 package com.taosdata.jdbc.cases;
 
+import org.junit.Assert;
 import org.junit.Test;
 
 import java.sql.Connection;
@@ -12,21 +13,19 @@ public class AppMemoryLeakTest {
     @Test(expected = SQLException.class)
     public void testCreateTooManyConnection() throws ClassNotFoundException, SQLException {
         Class.forName("com.taosdata.jdbc.TSDBDriver");
-        int conCnt = 0;
         while (true) {
             Connection conn = DriverManager.getConnection("jdbc:TAOS://localhost:6030/?user=root&password=taosdata");
-            System.out.println(conCnt++ + " : " + conn);
+            Assert.assertNotNull(conn);
         }
     }
 
     @Test(expected = Exception.class)
     public void testCreateTooManyStatement() throws ClassNotFoundException, SQLException {
         Class.forName("com.taosdata.jdbc.TSDBDriver");
-        int stmtCnt = 0;
         Connection conn = DriverManager.getConnection("jdbc:TAOS://localhost:6030/?user=root&password=taosdata");
         while (true) {
             Statement stmt = conn.createStatement();
-            System.out.println(++stmtCnt + " : " + stmt);
+            Assert.assertNotNull(stmt);
         }
     }
 

src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/AuthenticationTest.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/AuthenticationTest.java

-package com.taosdata.jdbc.rs;
+package com.taosdata.jdbc.cases;
 
 import org.junit.Before;
 import org.junit.Test;

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/BadLocaleSettingTest.java

+package com.taosdata.jdbc.cases;
+
+
+import com.taosdata.jdbc.TSDBDriver;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Properties;
+
+public class BadLocaleSettingTest {
+
+    private static final String host = "127.0.0.1";
+    private static final String dbName = "bad_locale_test";
+    private static Connection conn;
+
+    @Test
+    public void canSetLocale() {
+        try {
+            Properties properties = new Properties();
+            properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
+            properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
+            properties.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
+
+            String url = "jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata";
+            conn = DriverManager.getConnection(url, properties);
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbName);
+            stmt.execute("create database if not exists " + dbName);
+            stmt.execute("use " + dbName);
+            stmt.execute("drop table if exists weather");
+            stmt.execute("create table weather(ts timestamp, temperature float, humidity int)");
+            stmt.executeUpdate("insert into weather values(1624071506435, 12.3, 4)");
+            stmt.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @BeforeClass
+    public static void beforeClass() {
+        System.setProperty("sun.jnu.encoding", "ANSI_X3.4-1968");
+        System.setProperty("file.encoding", "ANSI_X3.4-1968");
+    }
+
+    @AfterClass
+    public static void afterClass() {
+        try {
+            if (conn != null)
+                conn.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+}
\ No newline at end of file

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/BatchErrorIgnoreTest.java

+package com.taosdata.jdbc.cases;
+
+import org.junit.*;
+
+import java.sql.*;
+import java.util.stream.IntStream;
+
+public class BatchErrorIgnoreTest {
+
+    private static final String host = "127.0.0.1";
+
+    @Test
+    public void batchErrorThrowException() throws SQLException {
+        // given
+        Connection conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
+
+        // when
+        try (Statement stmt = conn.createStatement()) {
+            IntStream.range(1, 6).mapToObj(i -> "insert into test.t" + i + " values(now, " + i + ")").forEach(sql -> {
+                try {
+                    stmt.addBatch(sql);
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            });
+            stmt.addBatch("insert into t11 values(now, 11)");
+            IntStream.range(6, 11).mapToObj(i -> "insert into test.t" + i + " values(now, " + i + "),(now + 1s, " + (10 * i) + ")").forEach(sql -> {
+                try {
+                    stmt.addBatch(sql);
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            });
+            stmt.addBatch("select count(*) from test.weather");
+
+            stmt.executeBatch();
+        } catch (BatchUpdateException e) {
+            int[] updateCounts = e.getUpdateCounts();
+            Assert.assertEquals(5, updateCounts.length);
+            Assert.assertEquals(1, updateCounts[0]);
+            Assert.assertEquals(1, updateCounts[1]);
+            Assert.assertEquals(1, updateCounts[2]);
+            Assert.assertEquals(1, updateCounts[3]);
+            Assert.assertEquals(1, updateCounts[4]);
+        }
+
+    }
+
+    @Test
+    public void batchErrorIgnore() throws SQLException {
+        // given
+        Connection conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata&batchErrorIgnore=true");
+
+        // when
+        int[] results = null;
+        try (Statement stmt = conn.createStatement()) {
+            IntStream.range(1, 6).mapToObj(i -> "insert into test.t" + i + " values(now, " + i + ")").forEach(sql -> {
+                try {
+                    stmt.addBatch(sql);
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            });
+            stmt.addBatch("insert into t11 values(now, 11)");
+            IntStream.range(6, 11).mapToObj(i -> "insert into test.t" + i + " values(now, " + i + "),(now + 1s, " + (10 * i) + ")").forEach(sql -> {
+                try {
+                    stmt.addBatch(sql);
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            });
+            stmt.addBatch("select count(*) from test.weather");
+
+            results = stmt.executeBatch();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        assert results != null;
+        Assert.assertEquals(12, results.length);
+        Assert.assertEquals(1, results[0]);
+        Assert.assertEquals(1, results[1]);
+        Assert.assertEquals(1, results[2]);
+        Assert.assertEquals(1, results[3]);
+        Assert.assertEquals(1, results[4]);
+        Assert.assertEquals(Statement.EXECUTE_FAILED, results[5]);
+        Assert.assertEquals(2, results[6]);
+        Assert.assertEquals(2, results[7]);
+        Assert.assertEquals(2, results[8]);
+        Assert.assertEquals(2, results[9]);
+        Assert.assertEquals(2, results[10]);
+        Assert.assertEquals(Statement.SUCCESS_NO_INFO, results[11]);
+    }
+
+    @Before
+    public void before() {
+        try {
+            Connection conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
+            Statement stmt = conn.createStatement();
+            stmt.execute("use test");
+            stmt.execute("drop table if exists weather");
+            stmt.execute("create table weather (ts timestamp, f1 float) tags(t1 int)");
+            IntStream.range(1, 11).mapToObj(i -> "create table t" + i + " using weather tags(" + i + ")").forEach(sql -> {
+                try {
+                    stmt.execute(sql);
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            });
+            stmt.close();
+            conn.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @BeforeClass
+    public static void beforeClass() {
+        try {
+            Connection conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists test");
+            stmt.execute("create database if not exists test");
+            stmt.close();
+            conn.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @AfterClass
+    public static void afterClass() {
+        try {
+            Connection conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists test");
+            stmt.close();
+            conn.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/BatchInsertTest.java

@@ -60,7 +60,6 @@ public class BatchInsertTest {
             final int index = i;
             executorService.execute(() -> {
                 try {
-                    long startTime = System.currentTimeMillis();
                     Statement statement = connection.createStatement(); // get statement
                     StringBuilder sb = new StringBuilder();
                     sb.append("INSERT INTO " + tablePrefix + index + " VALUES");
@@ -73,8 +72,6 @@ public class BatchInsertTest {
                     }
                     statement.addBatch(sb.toString());
                     statement.executeBatch();
-                    long endTime = System.currentTimeMillis();
-                    System.out.println("Thread " + index + " takes " + (endTime - startTime) + " microseconds");
                     connection.commit();
                     statement.close();
                 } catch (Exception e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ConnectMultiTaosdByRestfulWithDifferentTokenTest.java

 package com.taosdata.jdbc.cases;
 
 import com.taosdata.jdbc.TSDBDriver;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -9,13 +10,13 @@ import java.util.Properties;
 
 public class ConnectMultiTaosdByRestfulWithDifferentTokenTest {
 
-    private static String host1 = "192.168.17.156";
-    private static String user1 = "root";
-    private static String password1 = "tqueue";
+    private static final String host1 = "192.168.17.156";
+    private static final String user1 = "root";
+    private static final String password1 = "tqueue";
     private Connection conn1;
-    private static String host2 = "192.168.17.82";
-    private static String user2 = "root";
-    private static String password2 = "taosdata";
+    private static final String host2 = "192.168.17.82";
+    private static final String user2 = "root";
+    private static final String password2 = "taosdata";
     private Connection conn2;
 
     @Test
@@ -30,10 +31,8 @@ public class ConnectMultiTaosdByRestfulWithDifferentTokenTest {
         try (Statement stmt = connection.createStatement()) {
             ResultSet rs = stmt.executeQuery("select server_status()");
             ResultSetMetaData meta = rs.getMetaData();
+            Assert.assertNotNull(meta);
             while (rs.next()) {
-                for (int i = 1; i <= meta.getColumnCount(); i++) {
-                    System.out.println(meta.getColumnLabel(i) + ": " + rs.getString(i));
-                }
             }
         } catch (SQLException e) {
             e.printStackTrace();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/DatetimeBefore1970Test.java

 package com.taosdata.jdbc.cases;
 
 import com.taosdata.jdbc.utils.TimestampUtil;
-import org.junit.AfterClass;
-import org.junit.BeforeClass;
-import org.junit.Test;
+import org.junit.*;
 
 import java.sql.*;
 
 public class DatetimeBefore1970Test {
 
-    private static Connection conn;
+    private static final String host = "127.0.0.1";
+    private Connection conn;
 
     @Test
     public void test() {
         try (Statement stmt = conn.createStatement()) {
+            // given
             stmt.executeUpdate("insert into weather(ts) values('1969-12-31 23:59:59.999')");
             stmt.executeUpdate("insert into weather(ts) values('1970-01-01 00:00:00.000')");
             stmt.executeUpdate("insert into weather(ts) values('1970-01-01 08:00:00.000')");
             stmt.executeUpdate("insert into weather(ts) values('1970-01-01 07:59:59.999')");
+            ResultSet rs = stmt.executeQuery("select * from weather order by ts asc");
+            ResultSetMetaData metaData = rs.getMetaData();
+            Assert.assertEquals(2, metaData.getColumnCount());
+
+            // when
+            rs.next();
+            // then
+            Timestamp ts = rs.getTimestamp("ts");
+            Assert.assertEquals("1969-12-31 23:59:59.999", TimestampUtil.longToDatetime(ts.getTime()));
+
+            // when
+            rs.next();
+            // then
+            ts = rs.getTimestamp("ts");
+            Assert.assertEquals("1970-01-01 00:00:00.000", TimestampUtil.longToDatetime(ts.getTime()));
+
+            // when
+            rs.next();
+            // then
+            ts = rs.getTimestamp("ts");
+            Assert.assertEquals("1970-01-01 08:00:00.000", TimestampUtil.longToDatetime(ts.getTime()));
+
+            // when
+            rs.next();
+            // then
+            ts = rs.getTimestamp("ts");
+            Assert.assertEquals("1970-01-01 07:59:59.999", TimestampUtil.longToDatetime(ts.getTime()));
 
-            ResultSet rs = stmt.executeQuery("select * from weather");
-            while (rs.next()) {
-                Timestamp ts = rs.getTimestamp("ts");
-                System.out.println("long: " + ts.getTime() + ", string: " + TimestampUtil.longToDatetime(ts.getTime()));
-            }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
 
-    public static void main(String[] args) {
-        System.out.println("timestamp: " + Long.MAX_VALUE + ", string: " + TimestampUtil.longToDatetime(Long.MAX_VALUE));
-        System.out.println("timestamp: " + Long.MIN_VALUE + ", string: " + TimestampUtil.longToDatetime(Long.MIN_VALUE));
-        System.out.println("timestamp: " + 0 + ", string: " + TimestampUtil.longToDatetime(0));
-        System.out.println("timestamp: " + -1 + ", string: " + TimestampUtil.longToDatetime(-1));
-        String datetime = "1970-01-01 00:00:00.000";
-        System.out.println("timestamp: " + TimestampUtil.datetimeToLong(datetime) + ", string: " + datetime);
-        datetime = "1969-12-31 23:59:59.999";
-        System.out.println("timestamp: " + TimestampUtil.datetimeToLong(datetime) + ", string: " + datetime);
-    }
-
-    @BeforeClass
-    public static void beforeClass() {
+    @Before
+    public void before() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
-            conn = DriverManager.getConnection("jdbc:TAOS://127.0.0.1:6030/?user=root&password=taosdata");
+            conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
             Statement stmt = conn.createStatement();
             stmt.execute("drop database if exists test_timestamp");
             stmt.execute("create database if not exists test_timestamp keep 36500");
             stmt.execute("use test_timestamp");
             stmt.execute("create table weather(ts timestamp,f1 float)");
             stmt.close();
-        } catch (ClassNotFoundException | SQLException e) {
+        } catch (SQLException e) {
             e.printStackTrace();
         }
     }
 
-    @AfterClass
-    public static void afterClass() {
+    @After
+    public void after() {
         try {
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists test_timestamp");
             if (conn != null)
                 conn.close();
         } catch (SQLException e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/TD4174Test.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/DoubleQuoteInSqlTest.java

@@ -7,56 +7,64 @@ import org.junit.*;
 import java.sql.*;
 import java.util.Properties;
 
-public class TD4174Test {
-    private Connection conn;
+public class DoubleQuoteInSqlTest {
     private static final String host = "127.0.0.1";
+    private static final String dbname = "td4174";
+
+    private Connection conn;
 
     @Test
     public void test() {
+        // given
         long ts = System.currentTimeMillis();
+        JSONObject value = new JSONObject();
+        value.put("name", "John Smith");
+        value.put("age", 20);
+
+        // when
+        int ret = 0;
         try (PreparedStatement pstmt = conn.prepareStatement("insert into weather values(" + ts + ", ?)")) {
-            JSONObject value = new JSONObject();
-            value.put("name", "John Smith");
-            value.put("age", 20);
-            Assert.assertEquals("{\"name\":\"John Smith\",\"age\":20}",value.toJSONString());
             pstmt.setString(1, value.toJSONString());
-
-            int ret = pstmt.executeUpdate();
-            Assert.assertEquals(1, ret);
+            ret = pstmt.executeUpdate();
         } catch (SQLException e) {
             e.printStackTrace();
         }
-    }
 
-    public static void main(String[] args) {
-        JSONObject value = new JSONObject();
-        value.put("name", "John Smith");
-        value.put("age", 20);
-        System.out.println(value.toJSONString());
+        // then
+        Assert.assertEquals("{\"name\":\"John Smith\",\"age\":20}", value.toJSONString());
+        Assert.assertEquals(1, ret);
     }
 
     @Before
-    public void before() throws SQLException {
+    public void before() {
         String url = "jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata";
         Properties properties = new Properties();
         properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
         properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
         properties.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
 
-        conn = DriverManager.getConnection(url, properties);
-        try (Statement stmt = conn.createStatement()) {
-            stmt.execute("drop database if exists td4174");
-            stmt.execute("create database if not exists td4174");
-            stmt.execute("use td4174");
+        try {
+            conn = DriverManager.getConnection(url, properties);
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.execute("create database if not exists " + dbname);
+            stmt.execute("use " + dbname);
             stmt.execute("create table weather(ts timestamp, text binary(64))");
+        } catch (SQLException e) {
+            e.printStackTrace();
         }
     }
 
     @After
-    public void after() throws SQLException {
-        if (conn != null)
+    public void after() {
+        try {
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.close();
             conn.close();
-
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
     }
 
 }

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/DriverAutoloadTest.java

@@ -13,7 +13,7 @@ import java.util.Properties;
 public class DriverAutoloadTest {
 
     private Properties properties;
-    private String host = "127.0.0.1";
+    private final String host = "127.0.0.1";
 
     @Test
     public void testRestful() throws SQLException {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ImportTest.java

@@ -20,7 +20,6 @@ public class ImportTest {
     @BeforeClass
     public static void before() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             Properties properties = new Properties();
             properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
@@ -33,8 +32,6 @@ public class ImportTest {
             stmt.close();
 
             ts = System.currentTimeMillis();
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
         } catch (SQLException e) {
             e.printStackTrace();
         }
@@ -47,7 +44,6 @@ public class ImportTest {
             for (int i = 0; i < 50; i++) {
                 ts++;
                 int row = stmt.executeUpdate("import into " + dbName + "." + tName + " values (" + ts + ", " + (100 + i) + ", " + i + ")");
-                System.out.println("import into " + dbName + "." + tName + " values (" + ts + ", " + (100 + i) + ", " + i + ")\t" + row);
                 assertEquals(1, row);
             }
         }
@@ -84,7 +80,6 @@ public class ImportTest {
                 long t = (++ts) + a;
                 sqlBuilder.append("(").append(t).append(",").append((100 + i)).append(",").append(i).append(") ");
             }
-            System.out.println(sqlBuilder.toString());
             int rows = stmt.executeUpdate(sqlBuilder.toString());
             assertEquals(50, rows);
         } catch (SQLException e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/InsertDbwithoutUseDbTest.java

@@ -13,9 +13,9 @@ import java.util.Random;
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
 public class InsertDbwithoutUseDbTest {
 
-    private static String host = "127.0.0.1";
+    private static final String host = "127.0.0.1";
     private static Properties properties;
-    private static Random random = new Random(System.currentTimeMillis());
+    private static final Random random = new Random(System.currentTimeMillis());
 
     @Test
     public void case001() throws ClassNotFoundException, SQLException {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/InsertSpecialCharacterJniTest.java

@@ -8,14 +8,14 @@ public class InsertSpecialCharacterJniTest {
 
     private static final String host = "127.0.0.1";
     private static Connection conn;
-    private static String dbName = "spec_char_test";
-    private static String tbname1 = "test";
-    private static String tbname2 = "weather";
-    private static String special_character_str_1 = "$asd$$fsfsf$";
-    private static String special_character_str_2 = "\\\\asdfsfsf\\\\";
-    private static String special_character_str_3 = "\\\\asdfsfsf\\";
-    private static String special_character_str_4 = "?asd??fsf?sf?";
-    private static String special_character_str_5 = "?#sd@$f(('<(s[P)>\"){]}f?s[]{}%vaew|\"fsfs^a&d*jhg)(j))(f@~!?$";
+    private static final String dbName = "spec_char_test";
+    private static final String tbname1 = "test";
+    private static final String tbname2 = "weather";
+    private static final String special_character_str_1 = "$asd$$fsfsf$";
+    private static final String special_character_str_2 = "\\\\asdfsfsf\\\\";
+    private static final String special_character_str_3 = "\\\\asdfsfsf\\";
+    private static final String special_character_str_4 = "?asd??fsf?sf?";
+    private static final String special_character_str_5 = "?#sd@$f(('<(s[P)>\"){]}f?s[]{}%vaew|\"fsfs^a&d*jhg)(j))(f@~!?$";
 
     @Test
     public void testCase01() throws SQLException {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/InsertSpecialCharacterRestfulTest.java

@@ -8,14 +8,14 @@ public class InsertSpecialCharacterRestfulTest {
 
     private static final String host = "127.0.0.1";
     private static Connection conn;
-    private static String dbName = "spec_char_test";
-    private static String tbname1 = "test";
-    private static String tbname2 = "weather";
-    private static String special_character_str_1 = "$asd$$fsfsf$";
-    private static String special_character_str_2 = "\\\\asdfsfsf\\\\";
-    private static String special_character_str_3 = "\\\\asdfsfsf\\";
-    private static String special_character_str_4 = "?asd??fsf?sf?";
-    private static String special_character_str_5 = "?#sd@$f(('<(s[P)>\"){]}f?s[]{}%vaew|\"fsfs^a&d*jhg)(j))(f@~!?$";
+    private static final String dbName = "spec_char_test";
+    private static final String tbname1 = "test";
+    private static final String tbname2 = "weather";
+    private static final String special_character_str_1 = "$asd$$fsfsf$";
+    private static final String special_character_str_2 = "\\\\asdfsfsf\\\\";
+    private static final String special_character_str_3 = "\\\\asdfsfsf\\";
+    private static final String special_character_str_4 = "?asd??fsf?sf?";
+    private static final String special_character_str_5 = "?#sd@$f(('<(s[P)>\"){]}f?s[]{}%vaew|\"fsfs^a&d*jhg)(j))(f@~!?$";
 
     @Test
     public void testCase01() throws SQLException {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/InvalidResultSetPointerTest.java

@@ -8,13 +8,13 @@ import java.util.Properties;
 
 public class InvalidResultSetPointerTest {
 
-    private static String host = "127.0.0.1";
+    private static final String host = "127.0.0.1";
     private static final String dbName = "test";
     private static final String stbName = "stb";
     private static final String tbName = "tb";
     private static Connection connection;
-    private static int numOfSTb = 30000;
-    private static int numOfTb = 3;
+    private static final int numOfSTb = 30000;
+    private static final int numOfTb = 3;
     private static int numOfThreads = 100;
 
     @Test
@@ -74,7 +74,7 @@ public class InvalidResultSetPointerTest {
             b = numOfSTb % numOfThreads;
         }
 
-        multiThreadingClass instance[] = new multiThreadingClass[numOfThreads];
+        multiThreadingClass[] instance = new multiThreadingClass[numOfThreads];
 
         int last = 0;
         for (int i = 0; i < numOfThreads; i++) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/TwoTypeTimestampPercisionInJniTest.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/MicroSecondPrecisionJNITest.java

@@ -10,7 +10,7 @@ import org.junit.Test;
 import java.sql.*;
 import java.util.Properties;
 
-public class TwoTypeTimestampPercisionInJniTest {
+public class MicroSecondPrecisionJNITest {
 
     private static final String host = "127.0.0.1";
     private static final String ms_timestamp_db = "ms_precision_test";
@@ -41,7 +41,6 @@ public class TwoTypeTimestampPercisionInJniTest {
             rs.next();
 
             Timestamp timestamp = rs.getTimestamp(1);
-            System.out.println(timestamp);
             long ts = timestamp.getTime();
             Assert.assertEquals(timestamp1, ts);
             int nanos = timestamp.getNanos();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/TwoTypeTimestampPercisionInRestfulTest.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/MicroSecondPrecisionRestfulTest.java

@@ -10,10 +10,9 @@ import org.junit.Test;
 import java.sql.*;
 import java.util.Properties;
 
-public class TwoTypeTimestampPercisionInRestfulTest {
+public class MicroSecondPrecisionRestfulTest {
 
     private static final String host = "127.0.0.1";
-
     private static final String ms_timestamp_db = "ms_precision_test";
     private static final String us_timestamp_db = "us_precision_test";
     private static final long timestamp1 = System.currentTimeMillis();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/MultiThreadsWithSameStatmentTest.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/MultiThreadsWithSameStatementTest.java

@@ -7,21 +7,19 @@ import org.junit.Test;
 import java.sql.*;
 import java.util.concurrent.TimeUnit;
 
-public class MultiThreadsWithSameStatmentTest {
+public class MultiThreadsWithSameStatementTest {
 
-
-    private class Service {
+    private static class Service {
         public Connection conn;
         public Statement stmt;
 
         public Service() {
             try {
-                Class.forName("com.taosdata.jdbc.TSDBDriver");
                 conn = DriverManager.getConnection("jdbc:TAOS://localhost:6030/?user=root&password=taosdata");
                 stmt = conn.createStatement();
                 stmt.execute("create database if not exists jdbctest");
                 stmt.executeUpdate("create table if not exists jdbctest.weather (ts timestamp, f1 int)");
-            } catch (ClassNotFoundException | SQLException e) {
+            } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
@@ -48,10 +46,6 @@ public class MultiThreadsWithSameStatmentTest {
                 ResultSet resultSet = service.stmt.executeQuery("select * from jdbctest.weather");
                 while (resultSet.next()) {
                     ResultSetMetaData metaData = resultSet.getMetaData();
-                    for (int i = 1; i <= metaData.getColumnCount(); i++) {
-                        System.out.print(metaData.getColumnLabel(i) + ": " + resultSet.getString(i));
-                    }
-                    System.out.println();
                 }
                 resultSet.close();
                 service.release();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/NanoSecondTimestampJNITest.java

+package com.taosdata.jdbc.cases;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.sql.*;
+import java.time.Instant;
+import java.util.Random;
+
+public class NanoSecondTimestampJNITest {
+
+    private static final String host = "127.0.0.1";
+    private static final String dbname = "nano_sec_test";
+    private static final Random random = new Random(System.currentTimeMillis());
+    private static Connection conn;
+
+    @Test
+    public void insertUsingLongValue() {
+        // given
+        long ms = System.currentTimeMillis();
+        long ns = ms * 1000_000 + random.nextInt(1000_000);
+
+        // when
+        int ret = 0;
+        try (Statement stmt = conn.createStatement()) {
+            ret = stmt.executeUpdate("insert into weather(ts, temperature, humidity) values(" + ns + ", 12.3, 4)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertEquals(1, ret);
+    }
+
+    @Test
+    public void insertUsingStringValue() {
+        // given
+
+        // when
+        int ret = 0;
+        try (Statement stmt = conn.createStatement()) {
+            ret = stmt.executeUpdate("insert into weather(ts, temperature, humidity) values('2021-01-01 12:00:00.123456789', 12.3, 4)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertEquals(1, ret);
+    }
+
+    @Test
+    public void insertUsingTimestampValue() {
+        // given
+        long epochSec = System.currentTimeMillis() / 1000;
+        long nanoAdjustment = random.nextInt(1000_000_000);
+        Timestamp ts = Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
+
+        // when
+        int ret = 0;
+        String sql = "insert into weather(ts, temperature, humidity) values( ?, ?, ?)";
+        try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setTimestamp(1, ts);
+            pstmt.setFloat(2, 12.34f);
+            pstmt.setInt(3, 55);
+            ret = pstmt.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertEquals(1, ret);
+    }
+
+    @Test
+    public void selectUsingLongValue() throws SQLException {
+        // given
+        long ms = System.currentTimeMillis();
+        long ns = ms * 1000_000L + random.nextInt(1000_000);
+
+        // when
+        ResultSet rs = null;
+        try (Statement stmt = conn.createStatement()) {
+            stmt.executeUpdate("insert into weather(ts, temperature, humidity) values(" + ns + ", 12.3, 4)");
+            rs = stmt.executeQuery("select * from weather");
+            rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        long actual = rs.getLong(1);
+        Assert.assertEquals(ms, actual);
+        actual = rs.getLong("ts");
+        Assert.assertEquals(ms, actual);
+    }
+
+    @Test
+    public void selectUsingStringValue() throws SQLException {
+        // given
+        String timestampStr = "2021-01-01 12:00:00.123456789";
+
+        // when
+        ResultSet rs = null;
+        try (Statement stmt = conn.createStatement()) {
+            stmt.executeUpdate("insert into weather(ts, temperature, humidity) values('" + timestampStr + "', 12.3, 4)");
+            rs = stmt.executeQuery("select * from weather");
+            rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        String actual = rs.getString(1);
+        Assert.assertEquals(timestampStr, actual);
+        actual = rs.getString("ts");
+        Assert.assertEquals(timestampStr, actual);
+    }
+
+    @Test
+    public void selectUsingTimestampValue() throws SQLException {
+        // given
+        long timeMillis = System.currentTimeMillis();
+        long epochSec = timeMillis / 1000;
+        long nanoAdjustment = (timeMillis % 1000) * 1000_000L + random.nextInt(1000_000);
+        Timestamp ts = Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
+
+        // insert one row
+        String sql = "insert into weather(ts, temperature, humidity) values( ?, ?, ?)";
+        try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setTimestamp(1, ts);
+            pstmt.setFloat(2, 12.34f);
+            pstmt.setInt(3, 55);
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // when
+        ResultSet rs = null;
+        try (Statement stmt = conn.createStatement()) {
+            rs = stmt.executeQuery("select * from weather");
+            rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Timestamp actual = rs.getTimestamp(1);
+        Assert.assertEquals(ts, actual);
+        actual = rs.getTimestamp("ts");
+        Assert.assertEquals(ts, actual);
+        Assert.assertEquals(timeMillis, actual.getTime());
+        Assert.assertEquals(nanoAdjustment, actual.getNanos());
+    }
+
+    @Before
+    public void before() {
+        try (Statement stmt = conn.createStatement()) {
+            stmt.execute("drop table if exists weather");
+            stmt.execute("create table weather(ts timestamp, temperature float, humidity int)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @BeforeClass
+    public static void beforeClass() {
+        final String url = "jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata";
+        try {
+            conn = DriverManager.getConnection(url);
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.execute("create database if not exists " + dbname + " precision 'ns'");
+            stmt.execute("use " + dbname);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/NanoSecondTimestampRestfulTest.java

+package com.taosdata.jdbc.cases;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.sql.*;
+import java.time.Instant;
+import java.util.Random;
+
+public class NanoSecondTimestampRestfulTest {
+
+    private static final String host = "127.0.0.1";
+    private static final String dbname = "nano_sec_test";
+    private static final Random random = new Random(System.currentTimeMillis());
+    private static Connection conn;
+
+    @Test
+    public void insertUsingLongValue() {
+        // given
+        long ms = System.currentTimeMillis();
+        long ns = ms * 1000_000 + random.nextInt(1000_000);
+
+        // when
+        int ret = 0;
+        try (Statement stmt = conn.createStatement()) {
+            ret = stmt.executeUpdate("insert into weather(ts, temperature, humidity) values(" + ns + ", 12.3, 4)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertEquals(1, ret);
+    }
+
+    @Test
+    public void insertUsingStringValue() {
+        // given
+
+        // when
+        int ret = 0;
+        try (Statement stmt = conn.createStatement()) {
+            ret = stmt.executeUpdate("insert into weather(ts, temperature, humidity) values('2021-01-01 12:00:00.123456789', 12.3, 4)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertEquals(1, ret);
+    }
+
+    @Test
+    public void insertUsingTimestampValue() {
+        // given
+        long epochSec = System.currentTimeMillis() / 1000;
+        long nanoAdjustment = random.nextInt(1000_000_000);
+        Timestamp ts = Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
+
+        // when
+        int ret = 0;
+        String sql = "insert into weather(ts, temperature, humidity) values( ?, ?, ?)";
+        try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setTimestamp(1, ts);
+            pstmt.setFloat(2, 12.34f);
+            pstmt.setInt(3, 55);
+            ret = pstmt.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertEquals(1, ret);
+    }
+
+    @Test
+    public void selectUsingLongValue() throws SQLException {
+        // given
+        long ms = System.currentTimeMillis();
+        long ns = ms * 1000_000L + random.nextInt(1000_000);
+
+        // when
+        ResultSet rs = null;
+        try (Statement stmt = conn.createStatement()) {
+            stmt.executeUpdate("insert into weather(ts, temperature, humidity) values(" + ns + ", 12.3, 4)");
+            rs = stmt.executeQuery("select * from weather");
+            rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        long actual = rs.getLong(1);
+        Assert.assertEquals(ms, actual);
+        actual = rs.getLong("ts");
+        Assert.assertEquals(ms, actual);
+    }
+
+    @Test
+    public void selectUsingStringValue() throws SQLException {
+        // given
+        String timestampStr = "2021-01-01 12:00:00.123456789";
+
+        // when
+        ResultSet rs = null;
+        try (Statement stmt = conn.createStatement()) {
+            stmt.executeUpdate("insert into weather(ts, temperature, humidity) values('" + timestampStr + "', 12.3, 4)");
+            rs = stmt.executeQuery("select * from weather");
+            rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        String actual = rs.getString(1);
+        Assert.assertEquals(timestampStr, actual);
+        actual = rs.getString("ts");
+        Assert.assertEquals(timestampStr, actual);
+    }
+
+    @Test
+    public void selectUsingTimestampValue() throws SQLException {
+        // given
+        long timeMillis = System.currentTimeMillis();
+        long epochSec = timeMillis / 1000;
+        long nanoAdjustment = (timeMillis % 1000) * 1000_000L + random.nextInt(1000_000);
+        Timestamp ts = Timestamp.from(Instant.ofEpochSecond(epochSec, nanoAdjustment));
+
+        // insert one row
+        String sql = "insert into weather(ts, temperature, humidity) values( ?, ?, ?)";
+        try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setTimestamp(1, ts);
+            pstmt.setFloat(2, 12.34f);
+            pstmt.setInt(3, 55);
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // when
+        ResultSet rs = null;
+        try (Statement stmt = conn.createStatement()) {
+            rs = stmt.executeQuery("select * from weather");
+            rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Timestamp actual = rs.getTimestamp(1);
+        Assert.assertEquals(ts, actual);
+        actual = rs.getTimestamp("ts");
+        Assert.assertEquals(ts, actual);
+        Assert.assertEquals(timeMillis, actual.getTime());
+        Assert.assertEquals(nanoAdjustment, actual.getNanos());
+    }
+
+    @Before
+    public void before() {
+        try (Statement stmt = conn.createStatement()) {
+            stmt.execute("drop table if exists weather");
+            stmt.execute("create table weather(ts timestamp, temperature float, humidity int)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @BeforeClass
+    public static void beforeClass() {
+        final String url = "jdbc:TAOS-RS://" + host + ":6041/?user=root&password=taosdata";
+        try {
+            conn = DriverManager.getConnection(url);
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.execute("create database if not exists " + dbname + " precision 'ns'");
+            stmt.execute("use " + dbname);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/NullValueInResultSetForJdbcJniTest.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/NullValueInResultSetJNITest.java

@@ -6,7 +6,7 @@ import org.junit.Test;
 
 import java.sql.*;
 
-public class NullValueInResultSetForJdbcJniTest {
+public class NullValueInResultSetJNITest {
 
     private static final String host = "127.0.0.1";
     Connection conn;
@@ -17,11 +17,6 @@ public class NullValueInResultSetForJdbcJniTest {
             ResultSet rs = stmt.executeQuery("select * from weather");
             ResultSetMetaData meta = rs.getMetaData();
             while (rs.next()) {
-                for (int i = 1; i <= meta.getColumnCount(); i++) {
-                    Object value = rs.getObject(i);
-                    System.out.print(meta.getColumnLabel(i) + ": " + value + "\t");
-                }
-                System.out.println();
             }
 
         } catch (SQLException e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/NullValueInResultSetForJdbcRestfulTest.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/NullValueInResultSetRestfulTest.java

@@ -6,7 +6,7 @@ import org.junit.Test;
 
 import java.sql.*;
 
-public class NullValueInResultSetForJdbcRestfulTest {
+public class NullValueInResultSetRestfulTest {
 
     private static final String host = "127.0.0.1";
     Connection conn;
@@ -19,9 +19,7 @@ public class NullValueInResultSetForJdbcRestfulTest {
             while (rs.next()) {
                 for (int i = 1; i <= meta.getColumnCount(); i++) {
                     Object value = rs.getObject(i);
-                    System.out.print(meta.getColumnLabel(i) + ": " + value + "\t");
                 }
-                System.out.println();
             }
 
         } catch (SQLException e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/TD3841Test.java → src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/NullValueInResultSetTest.java

@@ -7,7 +7,7 @@ import org.junit.*;
 import java.sql.*;
 import java.util.Properties;
 
-public class TD3841Test {
+public class NullValueInResultSetTest {
     private static final String host = "127.0.0.1";
     private static Properties properties;
     private static Connection conn_restful;

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/PreparedStatementBatchInsertJNITest.java

+package com.taosdata.jdbc.cases;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.sql.*;
+import java.util.List;
+import java.util.Random;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class PreparedStatementBatchInsertJNITest {
+
+    private static final String host = "127.0.0.1";
+    private static final String dbname = "td4668";
+
+    private final Random random = new Random(System.currentTimeMillis());
+    private Connection conn;
+
+    @Test
+    public void test() {
+        // given
+        long ts = System.currentTimeMillis();
+        List<Object[]> rows = IntStream.range(0, 10).mapToObj(i -> {
+            Object[] row = new Object[6];
+            final String groupId = String.format("%02d", random.nextInt(100));
+            // table name (d + groupId)组合
+            row[0] = "d" + groupId;
+            // tag
+            row[1] = groupId;
+            // ts
+            row[2] = ts + i;
+            // current 电流
+            row[3] = random.nextFloat();
+            // voltage 电压
+            row[4] = Math.random() > 0.5 ? 220 : 380;
+            // phase 相位
+            row[5] = random.nextInt(10);
+            return row;
+        }).collect(Collectors.toList());
+        final String sql = "INSERT INTO ? (TS,CURRENT,VOLTAGE,PHASE) USING METERS TAGS (?)  VALUES (?,?,?,?)";
+
+        // when
+        try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            for (Object[] row : rows) {
+                for (int i = 0; i < row.length; i++) {
+                    pstmt.setObject(i + 1, row[i]);
+                }
+                pstmt.addBatch();
+            }
+            pstmt.executeBatch();
+        } catch (SQLException e) {
+            e.printStackTrace();
+            Assert.fail();
+        }
+
+        // then
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from meters");
+            int count = 0;
+            while (rs.next()) {
+                count++;
+            }
+            Assert.assertEquals(10, count);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Before
+    public void before() {
+        try {
+            conn = DriverManager.getConnection("jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata");
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.execute("create database if not exists " + dbname);
+            stmt.execute("use " + dbname);
+            stmt.execute("create table meters(ts timestamp, current float, voltage int, phase int) tags(groupId int)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @After
+    public void after() {
+        try {
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.close();
+            conn.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/PreparedStatementBatchInsertRestfulTest.java

+package com.taosdata.jdbc.cases;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.sql.*;
+import java.util.List;
+import java.util.Random;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class PreparedStatementBatchInsertRestfulTest {
+
+    private static final String host = "127.0.0.1";
+    private static final String dbname = "td4668";
+
+    private final Random random = new Random(System.currentTimeMillis());
+    private Connection conn;
+
+    @Test
+    public void test() {
+        // given
+        long ts = System.currentTimeMillis();
+        List<Object[]> rows = IntStream.range(0, 10).mapToObj(i -> {
+            Object[] row = new Object[6];
+            final String groupId = String.format("%02d", random.nextInt(100));
+            // table name (d + groupId)组合
+            row[0] = "d" + groupId;
+            // tag
+            row[1] = groupId;
+            // ts
+            row[2] = ts + i;
+            // current 电流
+            row[3] = random.nextFloat();
+            // voltage 电压
+            row[4] = Math.random() > 0.5 ? 220 : 380;
+            // phase 相位
+            row[5] = random.nextInt(10);
+            return row;
+        }).collect(Collectors.toList());
+        final String sql = "INSERT INTO ? (TS,CURRENT,VOLTAGE,PHASE) USING METERS TAGS (?)  VALUES (?,?,?,?)";
+
+        // when
+        try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            for (Object[] row : rows) {
+                for (int i = 0; i < row.length; i++) {
+                    pstmt.setObject(i + 1, row[i]);
+                }
+                pstmt.addBatch();
+            }
+            pstmt.executeBatch();
+        } catch (SQLException e) {
+            e.printStackTrace();
+            Assert.fail();
+        }
+
+        // then
+        try (Statement stmt = conn.createStatement()) {
+            ResultSet rs = stmt.executeQuery("select * from meters");
+            int count = 0;
+            while (rs.next()) {
+                count++;
+            }
+            Assert.assertEquals(10, count);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Before
+    public void before() {
+        try {
+            conn = DriverManager.getConnection("jdbc:TAOS-RS://" + host + ":6041/?user=root&password=taosdata");
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.execute("create database if not exists " + dbname);
+            stmt.execute("use " + dbname);
+            stmt.execute("create table meters(ts timestamp, current float, voltage int, phase int) tags(groupId int)");
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @After
+    public void after() {
+        try {
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.close();
+            conn.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/QueryDataTest.java

@@ -21,7 +21,6 @@ public class QueryDataTest {
     @Before
     public void createDatabase() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             Properties properties = new Properties();
             properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
@@ -36,7 +35,7 @@ public class QueryDataTest {
             String createTableSql = "create table " + stbName + "(ts timestamp, name binary(64))";
             statement.executeUpdate(createTableSql);
 
-        } catch (ClassNotFoundException | SQLException e) {
+        } catch (SQLException e) {
             return;
         }
     }
@@ -44,7 +43,6 @@ public class QueryDataTest {
     @Test
     public void testQueryBinaryData() throws SQLException {
         String insertSql = "insert into " + stbName + " values(now, 'taosdata')";
-        System.out.println(insertSql);
         statement.executeUpdate(insertSql);
 
         String querySql = "select * from " + stbName;
@@ -52,7 +50,6 @@ public class QueryDataTest {
 
         while (rs.next()) {
             String name = rs.getString(2);
-            System.out.println("name = " + name);
             assertEquals("taosdata", name);
         }
         rs.close();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ResetQueryCacheTest.java

@@ -34,8 +34,6 @@ public class ResetQueryCacheTest {
     public void testResetQueryCache() throws SQLException {
         String resetSql = "reset query cache";
         statement.execute(resetSql);
-        // ResultSet rs = statement.executeQuery(resetSql);
-        // rs.close();
     }
 
     @After

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/ResultSetMetaShouldNotBeNullRestfulTest.java

+package com.taosdata.jdbc.cases;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.sql.*;
+
+public class ResultSetMetaShouldNotBeNullRestfulTest {
+
+    private static final String host = "127.0.0.1";
+    private static final String dbname = "td4745";
+
+    private Connection connection;
+
+    @Test
+    public void testExecuteQuery() {
+        // given
+        ResultSetMetaData metaData = null;
+        int columnCount = -1;
+
+        // when
+        try {
+            Statement statement = connection.createStatement();
+            metaData = statement.executeQuery("select * from weather").getMetaData();
+            columnCount = metaData.getColumnCount();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertNotNull(metaData);
+        Assert.assertEquals(2, columnCount);
+    }
+
+    @Test
+    public void testExecute() {
+        // given
+        ResultSetMetaData metaData = null;
+        int columnCount = -1;
+        boolean execute = false;
+        // when
+        try {
+            Statement statement = connection.createStatement();
+            execute = statement.execute("select * from weather");
+            metaData = statement.getResultSet().getMetaData();
+            columnCount = metaData.getColumnCount();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        // then
+        Assert.assertEquals(true, execute);
+        Assert.assertNotNull(metaData);
+        Assert.assertEquals(2, columnCount);
+    }
+
+    @Before
+    public void before() {
+        try {
+            connection = DriverManager.getConnection("jdbc:TAOS-RS://" + host + ":6041/?user=root&password=taosdata");
+            Statement stmt = connection.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.execute("create database if not exists " + dbname);
+            stmt.execute("use " + dbname);
+            stmt.execute("create table weather (ts timestamp, temperature float)");
+            stmt.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @After
+    public void after() {
+        try {
+            Statement stmt = connection.createStatement();
+            stmt.execute("drop database if exists " + dbname);
+            stmt.close();
+            connection.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/SelectTest.java

@@ -19,7 +19,6 @@ public class SelectTest {
     @Before
     public void createDatabaseAndTable() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             Properties properties = new Properties();
             properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
@@ -31,8 +30,6 @@ public class SelectTest {
             stmt.execute("create database if not exists " + dbName);
             stmt.execute("create table if not exists " + dbName + "." + tName + " (ts timestamp, k int, v int)");
             stmt.close();
-        } catch (ClassNotFoundException e) {
-            return;
         } catch (SQLException e) {
             e.printStackTrace();
         }
@@ -47,7 +44,6 @@ public class SelectTest {
             for (int i = 0; i < 50; i++) {
                 ts++;
                 int row = stmt.executeUpdate("insert into " + dbName + "." + tName + " values (" + ts + ", " + (100 + i) + ", " + i + ")");
-                System.out.println("insert into " + dbName + "." + tName + " values (" + ts + ", " + (100 + i) + ", " + i + ")\t" + row);
                 assertEquals(1, row);
             }
 

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/StableTest.java

@@ -16,14 +16,13 @@ import static org.junit.Assert.assertEquals;
 public class StableTest {
 
     private static Connection connection;
-    private static String dbName = "test";
-    private static String stbName = "st";
-    private static String host = "127.0.0.1";
+    private static final String dbName = "test";
+    private static final String stbName = "st";
+    private static final String host = "127.0.0.1";
 
     @BeforeClass
     public static void createDatabase() {
         try {
-            Class.forName("com.taosdata.jdbc.TSDBDriver");
             Properties properties = new Properties();
             properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
             properties.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
@@ -34,8 +33,6 @@ public class StableTest {
             statement.execute("create database if not exists " + dbName);
             statement.execute("use " + dbName);
             statement.close();
-        } catch (ClassNotFoundException e) {
-            return;
         } catch (SQLException e) {
             e.printStackTrace();
         }
@@ -68,9 +65,6 @@ public class StableTest {
             String sql = "describe " + stbName;
             ResultSet rs = stmt.executeQuery(sql);
             while (rs.next()) {
-                for (int i = 1; i <= rs.getMetaData().getColumnCount(); i++) {
-                    System.out.println(i + ":" + rs.getString(i));
-                }
                 num++;
             }
             rs.close();
@@ -86,9 +80,6 @@ public class StableTest {
         try (Statement stmt = connection.createStatement()) {
             ResultSet rs = stmt.executeQuery("describe t1");
             while (rs.next()) {
-                for (int i = 1; i <= rs.getMetaData().getColumnCount(); i++) {
-                    System.out.printf("%d: %s\n", i, rs.getString(i));
-                }
                 num++;
             }
             rs.close();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/TD4144Test.java

-package com.taosdata.jdbc.cases;
-
-import com.taosdata.jdbc.TSDBConnection;
-import com.taosdata.jdbc.TSDBDriver;
-import com.taosdata.jdbc.TSDBResultSet;
-import com.taosdata.jdbc.TSDBSubscribe;
-import org.junit.AfterClass;
-import org.junit.BeforeClass;
-import org.junit.Test;
-
-import java.sql.DriverManager;
-import java.sql.ResultSetMetaData;
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.Properties;
-import java.util.concurrent.TimeUnit;
-
-public class TD4144Test {
-
-    private static TSDBConnection connection;
-    private static final String host = "127.0.0.1";
-
-    private static final String topic = "topic-meter-current-bg-10";
-    private static final String sql = "select * from meters where current > 10";
-    private static final String sql2 = "select * from meters where ts >= '2020-08-15 12:20:00.000'";
-
-
-    @Test
-    public void test() throws SQLException {
-        TSDBSubscribe subscribe = null;
-        TSDBResultSet res = null;
-        boolean hasNext = false;
-
-        try {
-            subscribe = connection.subscribe(topic, sql, false);
-            int count = 0;
-            while (true) {
-                // 等待1秒，避免频繁调用 consume，给服务端造成压力
-                TimeUnit.SECONDS.sleep(1);
-                if (res == null) {
-                    // 消费数据
-                    res = subscribe.consume();
-                    hasNext = res.next();
-                }
-
-                if (res == null) {
-                    continue;
-                }
-                ResultSetMetaData metaData = res.getMetaData();
-                int number = 0;
-                while (hasNext) {
-                    int columnCount = metaData.getColumnCount();
-                    for (int i = 1; i <= columnCount; i++) {
-                        System.out.print(metaData.getColumnLabel(i) + ": " + res.getString(i) + "\t");
-                    }
-                    System.out.println();
-                    count++;
-                    number++;
-                    hasNext = res.next();
-                    if (!hasNext) {
-                        res.close();
-                        res = null;
-                        System.out.println("rows： " + count);
-                    }
-                    if (hasNext == true && number >= 10) {
-                        System.out.println("batch" + number);
-                        break;
-                    }
-                }
-
-            }
-
-        } catch (SQLException | InterruptedException throwables) {
-            throwables.printStackTrace();
-        } finally {
-            if (subscribe != null)
-                subscribe.close(true);
-        }
-    }
-
-    @BeforeClass
-    public static void beforeClass() throws SQLException {
-        Properties properties = new Properties();
-        properties.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
-        properties.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
-        String url = "jdbc:TAOS://" + host + ":6030/?user=root&password=taosdata";
-        connection = (DriverManager.getConnection(url, properties)).unwrap(TSDBConnection.class);
-        try (Statement stmt = connection.createStatement()) {
-            stmt.execute("drop database if exists power");
-            stmt.execute("create database if not exists power");
-            stmt.execute("use power");
-            stmt.execute("create table meters(ts timestamp, current float, voltage int, phase int) tags(location binary(64), groupId int)");
-            stmt.execute("create table d1001 using meters tags(\"Beijing.Chaoyang\", 2)");
-            stmt.execute("create table d1002 using meters tags(\"Beijing.Haidian\", 2)");
-            stmt.execute("insert into d1001 values(\"2020-08-15 12:00:00.000\", 12, 220, 1),(\"2020-08-15 12:10:00.000\", 12.3, 220, 2),(\"2020-08-15 12:20:00.000\", 12.2, 220, 1)");
-            stmt.execute("insert into d1002 values(\"2020-08-15 12:00:00.000\", 9.9, 220, 1),(\"2020-08-15 12:10:00.000\", 10.3, 220, 1),(\"2020-08-15 12:20:00.000\", 11.2, 220, 1)");
-        }
-    }
-
-    @AfterClass
-    public static void afterClass() throws SQLException {
-        if (connection != null)
-            connection.close();
-    }
-}

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/TaosInfoMonitorTest.java

@@ -25,7 +25,7 @@ public class TaosInfoMonitorTest {
             return null;
         }).collect(Collectors.toList());
 
-        connectionList.stream().forEach(conn -> {
+        connectionList.forEach(conn -> {
             try (Statement stmt = conn.createStatement()) {
                 ResultSet rs = stmt.executeQuery("show databases");
                 while (rs.next()) {
@@ -37,7 +37,7 @@ public class TaosInfoMonitorTest {
             }
         });
 
-        connectionList.stream().forEach(conn -> {
+        connectionList.forEach(conn -> {
             try {
                 conn.close();
                 TimeUnit.MILLISECONDS.sleep(100);

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/UnsignedNumberJniTest.java

@@ -44,7 +44,7 @@ public class UnsignedNumberJniTest {
                 Assert.assertEquals(127, rs.getByte(2));
                 Assert.assertEquals(32767, rs.getShort(3));
                 Assert.assertEquals(2147483647, rs.getInt(4));
-                Assert.assertEquals(9223372036854775807l, rs.getLong(5));
+                Assert.assertEquals(9223372036854775807L, rs.getLong(5));
             }
         } catch (SQLException e) {
             e.printStackTrace();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/UnsignedNumberRestfulTest.java

@@ -45,7 +45,7 @@ public class UnsignedNumberRestfulTest {
                 Assert.assertEquals(127, rs.getByte(2));
                 Assert.assertEquals(32767, rs.getShort(3));
                 Assert.assertEquals(2147483647, rs.getInt(4));
-                Assert.assertEquals(9223372036854775807l, rs.getLong(5));
+                Assert.assertEquals(9223372036854775807L, rs.getLong(5));
             }
         } catch (SQLException e) {
             e.printStackTrace();

src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/RestfulDriverTest.java

@@ -8,11 +8,6 @@ import java.sql.*;
 public class RestfulDriverTest {
     private static final String host = "127.0.0.1";
 
-    @Test
-    public void connect() {
-
-    }
-
     @Test
     public void acceptsURL() throws SQLException {
         Driver driver = new RestfulDriver();
@@ -27,9 +22,7 @@ public class RestfulDriverTest {
         Driver driver = new RestfulDriver();
         final String url = "";
         DriverPropertyInfo[] propertyInfo = driver.getPropertyInfo(url, null);
-        for (DriverPropertyInfo prop : propertyInfo) {
-            System.out.println(prop);
-        }
+        Assert.assertNotNull(propertyInfo);
     }
 
     @Test

src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/RestfulPreparedStatementTest.java

@@ -15,6 +15,8 @@ public class RestfulPreparedStatementTest {
     private static PreparedStatement pstmt_insert;
     private static final String sql_select = "select * from t1 where ts > ? and ts <= ? and f1 >= ?";
     private static PreparedStatement pstmt_select;
+    private static final String sql_without_parameters = "select count(*) from t1";
+    private static PreparedStatement pstmt_without_parameters;
 
     @Test
     public void executeQuery() throws SQLException {
@@ -27,12 +29,9 @@ public class RestfulPreparedStatementTest {
         ResultSet rs = pstmt_select.executeQuery();
         Assert.assertNotNull(rs);
         ResultSetMetaData meta = rs.getMetaData();
-        while (rs.next()) {
-            for (int i = 1; i <= meta.getColumnCount(); i++) {
-                System.out.print(meta.getColumnLabel(i) + ": " + rs.getString(i) + "\t");
-            }
-            System.out.println();
-        }
+        int columnCount = meta.getColumnCount();
+        Assert.assertEquals(10, columnCount);
+        Assert.assertNotNull(rs);
     }
 
     @Test
@@ -240,6 +239,7 @@ public class RestfulPreparedStatementTest {
     @Test
     public void clearParameters() throws SQLException {
         pstmt_insert.clearParameters();
+        pstmt_without_parameters.clearParameters();
     }
 
     @Test
@@ -373,18 +373,20 @@ public class RestfulPreparedStatementTest {
     @BeforeClass
     public static void beforeClass() {
         try {
-            Class.forName("com.taosdata.jdbc.rs.RestfulDriver");
             conn = DriverManager.getConnection("jdbc:TAOS-RS://" + host + ":6041/?user=root&password=taosdata");
-            try (Statement stmt = conn.createStatement()) {
-                stmt.execute("drop database if exists test_pstmt");
-                stmt.execute("create database if not exists test_pstmt");
-                stmt.execute("use test_pstmt");
-                stmt.execute("create table weather(ts timestamp, f1 int, f2 bigint, f3 float, f4 double, f5 smallint, f6 tinyint, f7 bool, f8 binary(64), f9 nchar(64)) tags(loc nchar(64))");
-                stmt.execute("create table t1 using weather tags('beijing')");
-            }
+
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists test_pstmt");
+            stmt.execute("create database if not exists test_pstmt");
+            stmt.execute("use test_pstmt");
+            stmt.execute("create table weather(ts timestamp, f1 int, f2 bigint, f3 float, f4 double, f5 smallint, f6 tinyint, f7 bool, f8 binary(64), f9 nchar(64)) tags(loc nchar(64))");
+            stmt.execute("create table t1 using weather tags('beijing')");
+            stmt.close();
+
             pstmt_insert = conn.prepareStatement(sql_insert);
             pstmt_select = conn.prepareStatement(sql_select);
-        } catch (ClassNotFoundException | SQLException e) {
+            pstmt_without_parameters = conn.prepareStatement(sql_without_parameters);
+        } catch (SQLException e) {
             e.printStackTrace();
         }
     }
@@ -396,6 +398,8 @@ public class RestfulPreparedStatementTest {
                 pstmt_insert.close();
             if (pstmt_select != null)
                 pstmt_select.close();
+            if (pstmt_without_parameters != null)
+                pstmt_without_parameters.close();
             if (conn != null)
                 conn.close();
         } catch (SQLException e) {

src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/RestfulResultSetTest.java

@@ -95,13 +95,13 @@ public class RestfulResultSetTest {
     public void getBigDecimal() throws SQLException {
         BigDecimal f1 = rs.getBigDecimal("f1");
         long actual = (f1 == null) ? 0 : f1.longValue();
-        Assert.assertEquals(1609430400000l, actual);
+        Assert.assertEquals(1609430400000L, actual);
 
         BigDecimal f2 = rs.getBigDecimal("f2");
         Assert.assertEquals(1, f2.intValue());
 
         BigDecimal f3 = rs.getBigDecimal("f3");
-        Assert.assertEquals(100l, f3.longValue());
+        Assert.assertEquals(100L, f3.longValue());
 
         BigDecimal f4 = rs.getBigDecimal("f4");
         Assert.assertEquals(3.1415f, f4.floatValue(), 0.00000f);
@@ -125,13 +125,13 @@ public class RestfulResultSetTest {
         Assert.assertEquals(1, Ints.fromByteArray(f2));
 
         byte[] f3 = rs.getBytes("f3");
-        Assert.assertEquals(100l, Longs.fromByteArray(f3));
+        Assert.assertEquals(100L, Longs.fromByteArray(f3));
 
         byte[] f4 = rs.getBytes("f4");
-        Assert.assertEquals(3.1415f, Float.valueOf(new String(f4)), 0.000000f);
+        Assert.assertEquals(3.1415f, Float.parseFloat(new String(f4)), 0.000000f);
 
         byte[] f5 = rs.getBytes("f5");
-        Assert.assertEquals(3.1415926, Double.valueOf(new String(f5)), 0.000000f);
+        Assert.assertEquals(3.1415926, Double.parseDouble(new String(f5)), 0.000000f);
 
         byte[] f6 = rs.getBytes("f6");
         Assert.assertEquals("abc", new String(f6));
@@ -222,7 +222,7 @@ public class RestfulResultSetTest {
 
         Object f3 = rs.getObject("f3");
         Assert.assertEquals(Long.class, f3.getClass());
-        Assert.assertEquals(100l, f3);
+        Assert.assertEquals(100L, f3);
 
         Object f4 = rs.getObject("f4");
         Assert.assertEquals(Float.class, f4.getClass());
@@ -434,7 +434,7 @@ public class RestfulResultSetTest {
 
     @Test(expected = SQLFeatureNotSupportedException.class)
     public void updateLong() throws SQLException {
-        rs.updateLong(1, 1l);
+        rs.updateLong(1, 1L);
     }
 
     @Test(expected = SQLFeatureNotSupportedException.class)

src/connector/jdbc/src/test/java/com/taosdata/jdbc/utils/OSUtilsTest.java

@@ -10,17 +10,17 @@ public class OSUtilsTest {
 
     @Test
     public void inWindows() {
-        Assert.assertEquals(OS.indexOf("win") >= 0, OSUtils.isWindows());
+        Assert.assertEquals(OS.contains("win"), OSUtils.isWindows());
     }
 
     @Test
     public void isMac() {
-        Assert.assertEquals(OS.indexOf("mac") >= 0, OSUtils.isMac());
+        Assert.assertEquals(OS.contains("mac"), OSUtils.isMac());
     }
 
     @Test
     public void isLinux() {
-        Assert.assertEquals(OS.indexOf("nux") >= 0, OSUtils.isLinux());
+        Assert.assertEquals(OS.contains("nux"), OSUtils.isLinux());
     }
 
     @Before