String DB_URL =  "jdbc:mysql://localhost:3306/owl_db";  // URL of database
String DB_USER =   "owluser";                          // database user id
String DB_PASSWD = "owluserpwd";                          // database password
try{
    

      Class.forName ("com.mysql.jdbc.Driver");                         // Load the Driver
         conn=DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWD);
       stmt=conn.createStatement();

       
String sql ="INSERT INTO owl_subclass(subclass,superclass) VALUES ('branch','plant')";
stmt.executeUpdate(sql);
   
  rs=stmt.executeQuery("select * from owl_subclass");
  while(rs.next())
  {
      System.out.println(rs.getString(1));
    System.out.println(rs.getString(2));
   System.out.println(rs.getString(3)); }
rs.close();
stmt.close();
conn.close();

}catch(Exception e){
            System.out.println("the database is error!");
   }
finally{
       if (rs != null) {
           try {
               rs.close();
           } catch (Exception ignore) {
           }
       }
       if (stmt != null) {
           try {
               stmt.close();
           } catch (Exception ignore) {
           }
       }
       if (conn != null) {
           try {
               conn.close();
           } catch (Exception ignore) {
           }
       
   }
}
可是总是输出the database is error!
信息并没有被插入表中，请问这可能是什么问题，另外需要在数据源（odbc）中设置吗？可是里面没有mysql的选项。
另外我在设置dataexpress组件中的database中的connection时test connection也始终失败
显示信息是
com.borland.dx.dataset.DataSetException: The driver: com.mysql.jdbc.Driver  could not be loaded.  This could be a problem with the driver itself, or that the driver is not found on the classpath.
另外我是jbuilder2006 +mysql 4.0.26+mysql-connector-java-3.1.14
请各位大大指点 可能是什么问题？我已经试了很多次，都不行，郁闷中。请求帮助。

我将在线等，早上睡觉，其余时间在线等待，麻烦高人帮忙解决