[TD-2052]<feature>: common java connection pools examples

tests/examples/JDBC/connectionPools/README-cn.md

+这个example中，我们适配了java常见的连接池:
+* c3p0
+* dbcp
+* druid
+* HikariCP
+
+如何运行这个例子：
+```shell script
+
+
+
+```

tests/examples/JDBC/connectionPools/pom.xml

@@ -8,12 +8,11 @@
     <artifactId>connectionPools</artifactId>
     <version>1.0-SNAPSHOT</version>
 
-
     <dependencies>
         <dependency>
             <groupId>com.taosdata.jdbc</groupId>
             <artifactId>taos-jdbcdriver</artifactId>
-            <version>2.0.10</version>
+            <version>2.0.11</version>
         </dependency>
 
         <!-- druid -->
@@ -39,6 +38,12 @@
             <artifactId>commons-dbcp</artifactId>
             <version>1.4</version>
         </dependency>
+        <!-- c3p0 -->
+        <dependency>
+            <groupId>com.mchange</groupId>
+            <artifactId>c3p0</artifactId>
+            <version>0.9.5.2</version>
+        </dependency>
 
         <!-- log4j -->
         <dependency>

tests/examples/JDBC/connectionPools/src/main/java/com/taosdata/demo/ConnectionPoolDemo.java

 package com.taosdata.demo;
 
 import com.taosdata.demo.common.InsertTask;
+import com.taosdata.demo.pool.C3p0Builder;
 import com.taosdata.demo.pool.DbcpBuilder;
 import com.taosdata.demo.pool.DruidPoolBuilder;
 import com.taosdata.demo.pool.HikariCpBuilder;
@@ -17,17 +18,18 @@ import java.util.concurrent.TimeUnit;
 public class ConnectionPoolDemo {
 
     private static Logger logger = Logger.getLogger(DruidPoolBuilder.class);
+    private static final String dbName = "pool_test";
 
     private static int batchSize = 10;
     private static int sleep = 1000;
     private static int poolSize = 50;
     private static int tableSize = 1000;
     private static int threadCount = 50;
-    private static final String dbName = "pool_test";
+    private static String poolType = "hikari";
+
 
     public static void main(String[] args) throws InterruptedException {
         String host = null;
-
         for (int i = 0; i < args.length; i++) {
             if ("-host".equalsIgnoreCase(args[i]) && i < args.length - 1) {
                 host = args[++i];
@@ -44,6 +46,9 @@ public class ConnectionPoolDemo {
             if ("-tableSize".equalsIgnoreCase(args[i]) && i < args.length - 1) {
                 tableSize = Integer.parseInt(args[++i]);
             }
+            if ("-poolType".equalsIgnoreCase(args[i]) && i < args.length - 1) {
+                poolType = args[++i];
+            }
         }
         if (host == null) {
             System.out.println("Usage: java -jar XXX.jar " +
@@ -51,13 +56,29 @@ public class ConnectionPoolDemo {
                     "-batchSize <batchSize> " +
                     "-sleep <sleep> " +
                     "-poolSize <poolSize> " +
-                    "-tableSize <tableSize>");
+                    "-tableSize <tableSize>" +
+                    "-poolType <c3p0| dbcp| druid| hikari>");
             return;
         }
 
-//        DataSource dataSource = DbcpBuilder.getDataSource(host, poolSize);
-//        DataSource dataSource = DruidPoolBuilder.getDataSource(host, poolSize);
-        DataSource dataSource = HikariCpBuilder.getDataSource(host, poolSize);
+        DataSource dataSource;
+        switch (poolType) {
+            case "c3p0":
+                dataSource = C3p0Builder.getDataSource(host, poolSize);
+                break;
+            case "dbcp":
+                dataSource = DbcpBuilder.getDataSource(host, poolSize);
+                break;
+            case "druid":
+                dataSource = DruidPoolBuilder.getDataSource(host, poolSize);
+                break;
+            case "hikari":
+            default:
+                dataSource = HikariCpBuilder.getDataSource(host, poolSize);
+                poolType = "hikari";
+        }
+
+        logger.info(">>>>>>>>>>>>>> connection pool Type: " + poolType);
 
         init(dataSource);
 
@@ -78,7 +99,7 @@ public class ConnectionPoolDemo {
             for (int tb_ind = 1; tb_ind <= tableSize; tb_ind++) {
                 execute(conn, "create table t_" + tb_ind + " using weather tags('beijing'," + (tb_ind + 1) + ")");
             }
-            System.out.println(">>>>>>>>>>>>>>>>>>>>>>>>>>>> init finished.");
+            logger.info(">>>>>>>>>>>>>>>>>>>>>>>>>>>> init finished.");
         } catch (SQLException e) {
             e.printStackTrace();
         }

tests/examples/JDBC/connectionPools/src/main/java/com/taosdata/demo/common/InsertTask.java

@@ -10,7 +10,7 @@ import java.util.Random;
 
 public class InsertTask implements Runnable {
     private final Random random = new Random(System.currentTimeMillis());
-    private static Logger logger = Logger.getLogger(InsertTask.class);
+    private static final Logger logger = Logger.getLogger(InsertTask.class);
 
     private final DataSource ds;
     private final int batchSize;
@@ -37,14 +37,23 @@ public class InsertTask implements Runnable {
 
             for (int tb_index = 1; tb_index <= tableSize; tb_index++) {
                 StringBuilder sb = new StringBuilder();
-                sb.append("insert into " + dbName + ".t_" + tb_index + "(ts, temperature, humidity) values ");
+                sb.append("insert into ");
+                sb.append(dbName);
+                sb.append(".t_");
+                sb.append(tb_index);
+                sb.append("(ts, temperature, humidity) values ");
                 for (int i = 0; i < batchSize; i++) {
-                    sb.append("(" + (start + i) + ", " + (random.nextFloat() * 30) + ", " + (random.nextInt(70)) + ") ");
+                    sb.append("(");
+                    sb.append(start + i);
+                    sb.append(", ");
+                    sb.append(random.nextFloat() * 30);
+                    sb.append(", ");
+                    sb.append(random.nextInt(70));
+                    sb.append(") ");
                 }
                 logger.info("SQL >>> " + sb.toString());
                 affectedRows += stmt.executeUpdate(sb.toString());
             }
-
         } catch (SQLException e) {
             e.printStackTrace();
         } finally {
@@ -52,6 +61,7 @@ public class InsertTask implements Runnable {
                 try {
                     stmt.close();
                 } catch (SQLException e) {
+                    e.printStackTrace();
                 }
             }
             if (conn != null) {

tests/examples/JDBC/connectionPools/src/main/java/com/taosdata/demo/pool/C3p0Builder.java

+package com.taosdata.demo.pool;
+
+import com.mchange.v2.c3p0.ComboPooledDataSource;
+import org.apache.commons.dbcp.BasicDataSource;
+
+import javax.sql.DataSource;
+import java.beans.PropertyVetoException;
+
+public class C3p0Builder {
+
+    public static DataSource getDataSource(String host, int poolSize) {
+        ComboPooledDataSource ds = new ComboPooledDataSource();
+
+        try {
+            ds.setDriverClass("com.taosdata.jdbc.TSDBDriver");
+        } catch (PropertyVetoException e) {
+            e.printStackTrace();
+        }
+        ds.setJdbcUrl("jdbc:TAOS://" + host + ":6030");
+        ds.setUser("root");
+        ds.setPassword("taosdata");
+
+        ds.setMinPoolSize(poolSize);
+        ds.setMaxPoolSize(poolSize);
+        ds.setAcquireIncrement(5);
+        return ds;
+    }
+}

tests/examples/JDBC/connectionPools/src/main/resources/app.properties

-app.insertBatchSize=50
\ No newline at end of file