login.java

银行管理系统

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


public class Login extends JFrame implements ActionListener {
	
	JLabel _name,_password;
	JButton _logon,_exit;
	JTextField _jtfname;
	JPasswordField _jtfpassword;
	JPanel _jpname,_jppassword,_jpbutton;
	
    public Login() {
    	super("欢迎登录");
    	_name   =   new JLabel("用户名:");
    	_password = new JLabel("密    码:");
    	_logon = new JButton("登录");
    	_logon.addActionListener(this);
    	_exit  = new JButton("退出");
    	_exit.addActionListener(this);
    	_jtfname = new JTextField(16);
    	_jtfpassword = new JPasswordField(16);
    	_jpname = new JPanel();
    	_jppassword = new JPanel();
    	_jpbutton = new JPanel();
    	
    	_jpname.add(_name);
    	_jpname.add(_jtfname);
    	
    	_jppassword.add(_password);
    	_jppassword.add(_jtfpassword);
    	
    	_jpbutton.add(_logon);
    	_jpbutton.add(_exit);
    	
    	add(_jpname,"North");
    	add(_jppassword);
    	add(_jpbutton,"South");
    	
    	pack();
    	setVisible(true);
    	int W = (int)Toolkit.getDefaultToolkit().getScreenSize().getWidth();
    	int H = (int)Toolkit.getDefaultToolkit().getScreenSize().getHeight();
    	this.setLocation((W-this.getWidth())/2,(H-this.getHeight())/2);
    	this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    
    public static void main (String[] args) {
    	new Login();	
	}
	public void actionPerformed(ActionEvent e){
		if(e.getSource()==_logon){
			String username = _jtfname.getText().trim();
    		String password = new String(_jtfpassword.getPassword()).trim();
    		DB db = new DB();
    		if(db.login(username,password)){
    			JOptionPane.showMessageDialog(this,"登录成功");
    			new Select(username,password);
    			this.dispose();
    		}
    		else
    		{
    			JOptionPane.showMessageDialog(this,"登录失败，请确认您的输入正确!"+'\n'+"或者已经成功连接数据库!!!");
    		}
		}
		if(e.getSource()==_exit){
			System.exit(0);
		}
	}
}