java通过JFrame做一个登录系统的界面完整代码示例

package com.sxt;import java.awt.Container;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPasswordField;import javax.swing.JTextField;public class LoginFrame extends JFrame{	JTextField txtname=new JTextField();	JPasswordField txtpass=new JPasswordField();	JButton bl=new JButton("登录");	JButton bg=new JButton("关闭");	//构造无参构造器把主要的方法放在构造器里,然后在main方法里面调	public LoginFrame(){		setBounds(25,25,250,250);		Container c = getContentPane();		c.setLayout(new GridLayout(4,2,10,10));		c.add(new JLabel("用户名"));		c.add(txtname);		c.add(new JLabel("密码"));		c.add(txtpass);		c.add(bl);		c.add(bg);		setDefaultCloseOperation(EXIT_ON_CLOSE);		setVisible(true);		//注意：此处是匿名内部类		bg.addActionListener(new ActionListener(){			public void actionPerformed(ActionEvent e) {				// TODO Auto-generated method stub				System.exit(0);			}		}		);		//注意：此处是匿名内部类		bl.addActionListener(new ActionListener(){			public void actionPerformed(ActionEvent e) {				// TODO Auto-generated method stub				String name = txtname.getText();				String pass = txtpass.getText();				if(name.equals("tom")&&pass.equals("123")){					System.out.println("登陆成功");				} else{					System.out.println("登录失败");				}			}		}		);	}	public static void main(String[] args) {		new LoginFrame();	}}