login.java

中国水利水电出版社java程序设计教程,附源码

//Login.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class Login
{  
	public static void main(String[] args)
	{  
		LoginFrame frame = new LoginFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.show();
	}
}

class LoginFrame extends JFrame
{
	public LoginFrame()
	{
		setTitle("Login");
		setSize(WIDTH, HEIGHT);

		Container contentPane = getContentPane();

		//建立容器面板
		JPanel textPanel = new JPanel();

		//新建输入密码标签
		JLabel inputPassword = new JLabel("Input password: ", JLabel.CENTER);
		myPassword = new JPasswordField(20);
		textPanel.add(inputPassword);
		textPanel.add(myPassword);

		//新建密码验证标签
		JLabel checkedPassword = new JLabel("Checked password: ", JLabel.LEFT);
		checkPassword = new JTextField(20);
		checkPassword.setEditable(false);
		textPanel.add(checkedPassword);
		textPanel.add(checkPassword);

		loginButton = new JButton("登录", new ImageIcon("login.gif"));
		//注册事件监听器
		loginButton.addActionListener(new LoginAction());
		textPanel.add(loginButton);

		contentPane.add(textPanel);
	}

	//实现事件监听器
	private class LoginAction
		implements ActionListener
	{
		public void actionPerformed(ActionEvent event)
		{
			//获取密码域的内容
			char[] s = myPassword.getPassword();
			String gets = new String(s);

			if(gets.equals(CHECKPASSWORD))
			{
				checkPassword.setText("PASS!");
			}
			else
			{
				checkPassword.setText("WRONG PASSWORD!");
			}
		}
	}

	public static final int WIDTH = 280;
	public static final int HEIGHT = 180;
	public static final String CHECKPASSWORD = "password";
	private JPasswordField myPassword;
	private JTextField checkPassword;
	private JButton loginButton;
}