diff --git a/docs/examples/java/pom.xml b/docs/examples/java/pom.xml
index a48ba398da92f401235819d067aa2ba6f8b173ea..1165879156fc977d2c01e281d14fb16e10a09166 100644
--- a/docs/examples/java/pom.xml
+++ b/docs/examples/java/pom.xml
@@ -21,7 +21,7 @@
     <dependency>
       <groupId>com.taosdata.jdbc</groupId>
       <artifactId>taos-jdbcdriver</artifactId>
-      <version>2.0.38</version>
+      <version>2.0.39</version>
     </dependency>
 <!--    ANCHOR_END: dep-->
     <dependency>
diff --git a/docs/examples/java/src/main/java/com/taos/example/ConnectCloudExample.java b/docs/examples/java/src/main/java/com/taos/example/ConnectCloudExample.java
index 7c7cfbbd1cbdb6f1ffe7b344f30f8f5be295d0bf..68004ab0aa53a12f6fdb40a35a4a8253a7f54772 100644
--- a/docs/examples/java/src/main/java/com/taos/example/ConnectCloudExample.java
+++ b/docs/examples/java/src/main/java/com/taos/example/ConnectCloudExample.java
@@ -1,16 +1,19 @@
 package com.taos.example;
-import com.taosdata.jdbc.TSDBDriver;
 
 // ANCHOR: connect
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
+import java.sql.Statement;
 
 
 public class ConnectCloudExample {
     public static void main(String[] args) throws SQLException {
         String jdbcUrl = System.getenv("TDENGINE_JDBC_URL");
         Connection conn = DriverManager.getConnection(jdbcUrl);
+        Statement stmt = conn.createStatement();
+        // test the connection by firing a query
+        stmt.executeQuery("select server_version()");
         conn.close();
     }
 }
diff --git a/docs/examples/java/src/test/java/com/taos/test/TestAll.java b/docs/examples/java/src/test/java/com/taos/test/TestAll.java
index 42db24485afec05298159f7b0c3a4e15835d98ed..c9af09169fb1dbd3ad6026f4bf3d9a36a52daca8 100644
--- a/docs/examples/java/src/test/java/com/taos/test/TestAll.java
+++ b/docs/examples/java/src/test/java/com/taos/test/TestAll.java
@@ -9,83 +9,4 @@ import java.sql.*;
 @FixMethodOrder
 public class TestAll {
     private String[] args = new String[]{};
-
-    public void dropDB(String dbName) throws SQLException {
-        String jdbcUrl = "jdbc:TAOS://localhost:6030?user=root&password=taosdata";
-        try (Connection conn = DriverManager.getConnection(jdbcUrl)) {
-            try (Statement stmt = conn.createStatement()) {
-                stmt.execute("drop database if exists " + dbName);
-            }
-        }
-    }
-
-    public void insertData() throws SQLException {
-        String jdbcUrl = "jdbc:TAOS://localhost:6030?user=root&password=taosdata";
-        try (Connection conn = DriverManager.getConnection(jdbcUrl)) {
-            try (Statement stmt = conn.createStatement()) {
-                String sql = "INSERT INTO power.d1001 USING power.meters TAGS(California.SanFrancisco, 2) VALUES('2018-10-03 14:38:05.000',10.30000,219,0.31000)\n" +
-                        "                        power.d1001 USING power.meters TAGS(California.SanFrancisco, 2) VALUES('2018-10-03 15:38:15.000',12.60000,218,0.33000)\n" +
-                        "                        power.d1001 USING power.meters TAGS(California.SanFrancisco, 2) VALUES('2018-10-03 15:38:16.800',12.30000,221,0.31000)\n" +
-                        "                        power.d1002 USING power.meters TAGS(California.SanFrancisco, 3) VALUES('2018-10-03 15:38:16.650',10.30000,218,0.25000)\n" +
-                        "                        power.d1003 USING power.meters TAGS(California.LosAngeles, 2) VALUES('2018-10-03 15:38:05.500',11.80000,221,0.28000)\n" +
-                        "                        power.d1003 USING power.meters TAGS(California.LosAngeles, 2) VALUES('2018-10-03 15:38:16.600',13.40000,223,0.29000)\n" +
-                        "                        power.d1004 USING power.meters TAGS(California.LosAngeles, 3) VALUES('2018-10-03 15:38:05.000',10.80000,223,0.29000)\n" +
-                        "                        power.d1004 USING power.meters TAGS(California.LosAngeles, 3) VALUES('2018-10-03 15:38:06.000',10.80000,223,0.29000)\n" +
-                        "                        power.d1004 USING power.meters TAGS(California.LosAngeles, 3) VALUES('2018-10-03 15:38:07.000',10.80000,223,0.29000)\n" +
-                        "                        power.d1004 USING power.meters TAGS(California.LosAngeles, 3) VALUES('2018-10-03 15:38:08.500',11.50000,221,0.35000)";
-
-                stmt.execute(sql);
-            }
-        }
-    }
-
-    @Test
-    public void testJNIConnect() throws SQLException {
-        JNIConnectExample.main(args);
-    }
-
-    @Test
-    public void testRestConnect() throws SQLException {
-        RESTConnectExample.main(args);
-    }
-
-    @Test
-    public void testRestInsert() throws SQLException {
-        dropDB("power");
-        RestInsertExample.main(args);
-        RestQueryExample.main(args);
-    }
-
-    @Test
-    public void testStmtInsert() throws SQLException {
-        dropDB("power");
-        StmtInsertExample.main(args);
-    }
-
-    @Test
-    public void testSubscribe() {
-
-        Thread thread = new Thread(() -> {
-            try {
-                Thread.sleep(1000);
-                insertData();
-            } catch (SQLException e) {
-                e.printStackTrace();
-            } catch (InterruptedException e) {
-                e.printStackTrace();
-            }
-        });
-        thread.start();
-        SubscribeDemo.main(args);
-    }
-
-    @Test
-    public void testSchemaless() throws SQLException {
-        LineProtocolExample.main(args);
-        TelnetLineProtocolExample.main(args);
-        // for json protocol, tags may be double type. but for telnet protocol tag must be nchar type.
-        // To avoid type mismatch, we delete database test.
-        dropDB("test");
-        JSONProtocolExample.main(args);
-    }
 }