Java新手求指导啊，当登录名与密码数据库中有时，登录成功。登录的监听怎么写啊

这是登录窗体JLabel user=new JLabel("用户名"); user.setFont(new Font(systemFontName,Font.BOLD,24)); user.setForeground(Color.blue); user.setAlignmentY(CENTER_ALIGNMENT); user.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED,Color.green,Color.green)); userField=new JTextField(20); userField.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED,Color.green,Color.green)); userField.setForeground(Color.blue); userField.setFont(new Font(systemFontName,Font.BOLD,30)); userField.setOpaque(false); // JLabel password=new JLabel("密　码"); password.setFont(new Font(systemFontName,Font.BOLD,24)); password.setForeground(Color.blue); password.setAlignmentY(CENTER_ALIGNMENT); password.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED,Color.green,Color.green)); passwordField=new JTextField(20); passwordField.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED,Color.green,Color.green)); passwordField.setForeground(Color.blue); passwordField.setFont(new Font(systemFontName,Font.BOLD,30)); passwordField.setOpaque(false);这是数据库中的表求帮忙啊这是按钮JButton OKButton=new JButton("确　定"); QueRen1ButtonListener qr1Listener=new QueRen1ButtonListener(); OKButton.addActionListener(qr1Listener); JButton cancelButton=new JButton("取　消"); TuiChu1ButtonListener tuichu1Listener=new TuiChu1ButtonListener(); cancelButton.addActionListener(tuichu1Listener);确定按钮要实现：当输入的用户名和密码在数据库中存在时，跳转到新窗体