actionexam.java

java学习课件

package ch8;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ActionExam extends JFrame implements ActionListener 
{
  String name="张台山";
  String pass="zhang790123";
  JTextField tName=new JTextField();
  JPasswordField tPass=new JPasswordField();
  JButton button1=new JButton("重置");
  JButton button2=new JButton("提交");
  public ActionExam() //构造方法
  {
    setTitle("用户登录");
    setSize(200,150);
    Container  contentPane=getContentPane();
    contentPane.setLayout(new GridLayout(3,2));//设置组件的摆放布局为3行2列
    contentPane.add(new Label("用户名")); //将标签摆放到窗口上
    contentPane.add(tName);  //将tName摆放到窗口上
    contentPane.add(new Label("密码"));  //将标签摆放到窗口上
    contentPane.add(tPass);  //将tPass摆放到窗口上
    contentPane.add(button1);
    contentPane.add(button2);
    button1.addActionListener(this); //委派监听对象监听按钮事件
    button2.addActionListener(this); //委派监听对象监听按钮事件
    tPass.setEchoChar('*');
    setVisible(true); //设置框架窗口是可见的
    this.setDefaultCloseOperation(3);
  }
  public void actionPerformed(ActionEvent e) //实现ActionListeren接口的方法
  {
    Object obj=e.getSource();
    if(obj==button1)
    { 
      tName.setText("");
      tPass.setText("");
      tName.requestFocus(true);
    }
    else if(obj==button2)
    {
      if(!(name.equals(tName.getText().trim())))
      {
      	JOptionPane.showMessageDialog(null,"用户名错误!请校核!!!");
      	tName.requestFocus(true);
      	return;
      }
      if(!(pass.equals(new String(tPass.getPassword()))))
      {
      	JOptionPane.showMessageDialog(null,"密码错误!请重新输入!!!");
      	tPass.setText("");
      	tPass.requestFocus(true);
        return;  
      }
      JOptionPane.showMessageDialog(null,"ok!登录成功!!!");
      System.exit(0);
      
    }
  }
  public static void main(String args[]) 
  {
	   new ActionExam();
  }
}