请看下列代码,教我怎么改就可以一点注册按钮出来注册窗口,然后判断用户名和密码不能为空

package org.xzthtq.pbdevj.client.demo;

/*
* 设置登录窗口
*/

import java.awt.Component;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.AbstractButton;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
@SuppressWarnings("serial")
public class LandDemo extends JFrame {
static class btnListener implements ActionListener{

@Override
public void actionPerformed(ActionEvent e) {
String userName = txt.getText();//获得输入用户名
String password = paw.getText();//获得输入的密码

if (userName == null || "".equals(userName)//判断用户名和密码是否为空
|| password == null || "".equals(password)) {
JOptionPane.showMessageDialog(frame, "用户名和密码不能为空！");//弹出提示窗口
return;
}
}

public void init(){
AbstractButton btnl1 = null;
btnl1.addActionListener(new btnListener());

}
static final long serialVersionUID = 1L;

private static final ActionListener ActionListener = null;
private static JButton jButton;
private static Object ActionEvent;
private static AbstractButton txt;
private static AbstractButton paw;
private static Component frame;

public static <e> void main(String[] args) {
LandDemo n=new LandDemo();
n.init();

JFrame f=new JFrame("音乐共享平台");//添加窗体
JPanel p=new JPanel();
JLabel L = new JLabel(new ImageIcon("F://456.jpg")){//导入图片
};
JLabel nameMessageLabel = new JLabel();
f.add(p);//把面板添加到窗体中
p.add(L);
//登录按钮
jButton = new JButton("登陆");
JButton btnl1 = jButton;
btnl1.setBounds(390, 270, 90, 40);//设置按钮大小位置
L.add( btnl1);
//注册按钮
JButton btnl2 = new JButton("注册");
btnl2.setBounds(530, 270, 90, 40);
L.add(btnl2);
//用户名输入标签
JTextField txt = new JTextField("");
txt.setBounds(530,180, 110,30);
L.add(txt);
//密码输入标签
JPasswordField paw = new JPasswordField("");
paw.setBounds(530,220, 110,30);
L.add(paw);
//用户名标签
JLabel labl1 = new JLabel();
labl1.setBounds(390,150,150,90);
labl1.setFont(new Font("", Font.BOLD, 22));
labl1.setText("用户名");
L.add(labl1);
//密码标签
JLabel labl2 = new JLabel();
labl2.setBounds(390,200,150,90);
labl2.setText("密码");
L.add(labl2);
labl2.setFont(new Font("", Font.BOLD, 22));
L.setLayout(null);
f.setSize(700,500); //设置窗体大小
f.setVisible(true);
}
}

public void init() {
// TODO Auto-generated method stub

}
}

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