Java-GUI更新按钮

Question

我正在尝试在GUI表单中创建一个可以在数据库中编辑记录的更新按钮，但是我缺少希望有人帮助我的东西

这是更新方法的代码：

public int updateUser(Login user) //int
{
    DatabaseConnection dbconn = new DatabaseConnection();
    Connection conn = dbconn.getConn();

    int rows = 0;
    try 
    {
        String sql = "UPDATE LOGIN set USER_NAME = ? ,  PASSWORD = ? , PRIVILEGE_ID = ?";
        PreparedStatement pStm = conn.prepareStatement(sql);
        //fill SQL parameters from user: //
        pStm.setString(1, user.getUserName());
        pStm.setString(2, user.getPassword());
        pStm.setInt(3, user.getPrivilegeId());
        rows = 
                pStm.executeUpdate();
    }
    catch (SQLException ex) {
        System.out.println("SQLException: " + ex.getMessage());
    }
    finally
    {
        try {
            conn.close();
        } catch (SQLException ex) {
            System.out.println("SQLException: " + ex.getMessage());;
        }
    }
    return rows;
}

java swing中用于更新按钮的代码：

private void updateUserLayerActionPerformed(java.awt.event.ActionEvent evt) {                                                
     // 1-get data from user and check it: //
    String _name = nameLayer.getText().trim();
    String _paswrd = passLayer.getText().trim();
    String _prvName = privLayer.getSelectedItem().toString();

    //get Privilege_Id from DB:
    PrivilegeHandeler prvHndler = new PrivilegeHandeler();
    int prvId = prvHndler.getPrivilegeByName(_prvName);

    if(_name.length() >0 && _paswrd.length() >0 && prvId> 0)
    {
        Login user = new Login();
        user.setUserName(_name);
        user.setPassword(_paswrd);
        user.setPrivilegeId(prvId);

        //update User: //
        loginHandeler loghndlr = new loginHandeler();

        int rows = 
                loghndlr.updateUser(user);


        if (rows >0)
        {
            usrFormErorr.setText("user has been added successfully :)");
            nameLayer.setText("");
            passLayer.setText("");
            privLayer.setSelectedIndex(0);
        }
        else
        {
            usrFormErorr.setText("updated failed, try again");
        }
    }

    else
    {
        usrFormErorr.setText("please, fill the required fields first");
    }
}

我的问题是这样

1-我正在尝试输入要编辑的信息，然后进行更新，但总是收到更新失败的错误，请再试一次，以使其在出现问题时得到消息

请帮助。一个工作代码将是非常感谢。预先感谢。