Java学习——用户电话输入显示

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

class window8 extends JFrame implements ActionListener{
    JTextField namtxt , photxt,tishi;
    JTextArea btxt ;
    JComboBox jcb;
    
    JLabel name,phone;
    JButton show,quit;
    window8(){
        Container con = getContentPane();
        con.setLayout(new FlowLayout());
        btxt=new JTextArea(10,12);
        
        //下拉框
        //String str1[] = {"fdsa", "fgs", "gfh", "345354","fff"};
        //jcb = new JComboBox(str1); 
        //con.add(jcb);
        
        JScrollPane scroll = new JScrollPane(btxt);
        scroll.setBounds(0, 0, 500, 500);
        //默认的设置是超过文本框才会显示滚动条，以下设置让滚动条一直显示
        scroll.setVerticalScrollBarPolicy( JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        
        name=new JLabel("用户名",JLabel.CENTER);
        phone=new JLabel("电话",JLabel.CENTER);
        namtxt=new JTextField(10);
        photxt=new JTextField(10);
        tishi=new JTextField(15);
        show=new JButton("显示");
        quit=new JButton("退出");
        
        //把滚动条添加到容器里面
        con.add(scroll);
        con.add(name);
        con.add(namtxt);
        con.add(phone);
        con.add(photxt);
        con.add(tishi);
        con.add(show);
        con.add(quit);
        
        show.addActionListener(this);
        quit.addActionListener(this);
        
        this.setBounds(100,100,550,550);
        this.setVisible(true);
        validate();
    }
    public void actionPerformed(ActionEvent e) {
        if(e.getSource()==show) {
            StringBuffer str1,str2;
            str1 = new StringBuffer(namtxt.getText());
            str2 = new StringBuffer(photxt.getText());
            btxt.setText(btxt.getText()+"\n"+"用户名："+str1+"\n电话："+str2);
            tishi.setText("你正在输入信息");
        }
        else if(e.getSource()==quit) {
            System.exit(0);            
        }        
    }
}

public class PhoneNumber {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        window8 win = new window8();
        win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);       
    }
}