public static void test(){
       //1.数据库驱动类名的字符串
        String driver = "com.mysql.jdbc.Driver";
      //2.用户名
       String username = root;
      //3.密码
       String password = "root";
      //4.加载数据库驱动(加载成功后，会把Driver的实例注册到DriverManager中)
      try{
      Class.forName(driver);   
      Connection conn = null;
      Statemnet stmt = null;
　　//5.获取数据库连接
      conn = DriverManager.getConnection();  
　　//6.获取连接对象      
　　　　Statement stmt = conn.createStatement();
   //7.开启手动提交事务  
　　conn.setAutoCommit(false);   
  //8.执行sql语句 
    stmt.executeUpdate("update student set money=? where id =?",new int[]{8,1})
　　stmt.executeUpdate("update student set money=? where id=?",new int[]{12,2});
   //9.提交事务  
   conn.commit();
     } catch(Exception e){
    //10.回滚事务    
    conn.rollback();
       }



}