change

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

@@ -75,7 +75,6 @@ public class TSDBStatement implements Statement {
         }
 
         long resultSetPointer = this.connector.getResultSet();
-
         if (resultSetPointer == TSDBConstants.JNI_CONNECTION_NULL) {
             this.connector.freeResultSet(pSql);
             throw new SQLException(TSDBConstants.FixErrMsg(TSDBConstants.JNI_CONNECTION_NULL));

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

@@ -10,27 +10,35 @@ import java.util.concurrent.TimeUnit;
 import java.util.stream.IntStream;
 
 public class MultiThreadsWithSameStatmentTest {
-    private Connection conn;
-    private Statement stmt;
+
+
+    private 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) {
+                e.printStackTrace();
+            }
+        }
+    }
 
     @Before
     public void before() {
-        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) {
-            e.printStackTrace();
-        }
     }
 
     @Test
     public void test() {
         Thread t1 = new Thread(() -> {
             try {
-                ResultSet resultSet = stmt.executeQuery("select * from jdbctest.weather");
+                Service service = new Service();
+                ResultSet resultSet = service.stmt.executeQuery("select * from jdbctest.weather");
                 while (resultSet.next()) {
                     ResultSetMetaData metaData = resultSet.getMetaData();
                     for (int i = 1; i <= metaData.getColumnCount(); i++) {
@@ -40,7 +48,6 @@ public class MultiThreadsWithSameStatmentTest {
                 }
 
                 resultSet.close();
-
             } catch (SQLException e) {
                 e.printStackTrace();
             }
@@ -48,7 +55,8 @@ public class MultiThreadsWithSameStatmentTest {
 
         Thread t2 = new Thread(() -> {
             try {
-                stmt.executeUpdate("insert into jdbctest.weather values(now,1)");
+                Service service = new Service();
+                service.stmt.executeUpdate("insert into jdbctest.weather values(now,1)");
             } catch (SQLException e) {
                 e.printStackTrace();
             }