login.java

Java流的程序源码

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

public class Login {
	
	JFrame jf;
	JLabel lab1, lab2;
	JTextField text;
	JPasswordField pw;
	JButton jb1, jb2;

	public static void main(String[] args) throws Exception {
		
		new Login();
	}

	public Login() {
		
		jf = new JFrame("登陆界面");
		lab1 = new JLabel("请输入用户名:");
		lab2 = new JLabel("请输入用户密码:");
		pw = new JPasswordField(12);
		text = new JTextField();
		
		jf.setLayout(new GridLayout(3, 2));
		jf.setSize(300, 120);
		jf.setLocation(400, 300);
		jf.setVisible(true);
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		jb1 = new JButton("确定");
		jb2 = new JButton("取消");
		
		Container container = jf.getContentPane();
		
		container.add(lab1);
		container.add(text);
		container.add(lab2);
		container.add(pw);
		container.add(jb1);
		container.add(jb2);
		
		jb1.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if (text.getText().trim().equals("")) {
					JOptionPane.showMessageDialog(null, "请输入用户名!");
					return;
				}
				if (new String(pw.getPassword()).equals("")) {
					JOptionPane.showMessageDialog(null, "请输入密码!");
				}
				if (new String(pw.getPassword()).equals("1234")) {
					JFrame newframe = new theMain();
					newframe.setSize(400, 400);
					newframe.setLocation(340,250);
					newframe.setVisible(true);
					jf.dispose();
				}else
				{
					JOptionPane.showMessageDialog(null,"密码错误");
				}
			}
		});
		jb2.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				System.exit(0);
			}
		});
	}
}