java怎么这么实现一个界面？

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
/*
 *  @author xuesejinghun
 */
public class KeyWord {
 JFrame jf;
 JPanel jp;
 JTextField keyWordRandom;
 JTextField keyWordInput;
 JTextField keyWordJudge;
 JButton confirm;
 JButton next;
 //用于存储关键字，goto和const未包含在内
 public static String[] keyWords={"abstract","assert","boolean","break","byte",
  "case","catch","char","class","continue","default","do","double",
  "else","enum","extends","final","finally","float","for","if",
  "implements","import","instanceof","int","interface","long",
  "native","new","package","private","protected","public","return",
  "short","static","strictfp","super","switch","synchronized",
  "this","throw","throws","transient","try","void","volatile","while"};
 /*
  * 构造器
  */
 public KeyWord()
 {
  init();
 }
 /*
  * 初始化界面
  */
 public void init()
 {
  jf = new JFrame("Java 关键字");
  jp = new JPanel();
  keyWordRandom = new JTextField(15);
  keyWordInput = new JTextField("输入关键字",15);
  keyWordJudge = new JTextField("判断是否是关键字",15);
  generateKeyWord();
  confirm = new JButton("确认");
  //添加监听器
  confirm.addActionListener(new ActionListener(){
   @Override
   public void actionPerformed(ActionEvent e) {
    //判断输入文本域和自动生成的java关键字是否相同
    //如果要判断是否是关键字，请调用isKeyWord()方法,（被注释的部分）
    if(keyWordRandom.getText().equals(keyWordInput.getText()))
    {
     keyWordJudge.setText("true");
    }
    else
    {
     keyWordJudge.setText("false");
    }
   }
   
  });
  next = new JButton("下一个");
  //添加监听器
  next.addActionListener(new ActionListener(){
   @Override
   public void actionPerformed(ActionEvent e) {
    if("true".equals(keyWordJudge.getText()))
     generateKeyWord();
   }
   
  });
  jp.add(keyWordRandom);
  jp.add(keyWordInput);
  jp.add(confirm);
  jp.add(keyWordJudge);
  jp.add(next);
  jf.add(jp);
  
  jf.setSize(250, 300);
  jf.setVisible(true);
  jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 }
 /*
  * 随机生成关键字
  */
 public void generateKeyWord()
 {
  Random rd = new Random(System.currentTimeMillis());//以系统当前时间作为种子
  int index = rd.nextInt(keyWords.length);
  keyWordRandom.setText(keyWords[index]);
 }
 /*
  * 判断是否是关键字
  */
 /*
 public boolean isKeyWord()
 {
  boolean flag = false;
  String content = keyWordInput.getText();
  for(String str:keyWords)
  {
   if(str.equals(content))
   {
    flag = true;
    break;
   }
  }
  return flag;
 }*/
 public static void main(String[]args)
 {
  new KeyWord();
 }
}

感觉好像是贴吧的验证码？