编写一个简易的浏览器程序

package ysl;


import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;

import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;

public class Browser extends JFrame implements ActionListener,Runnable,HyperlinkListener {

JEditorPane editPane;//显示网络资源的文本区
JScrollPane jScrollPane;//滚动条
JTextField textFldOfURLAddress,prompt;//显示网络地址的文本框
JLabel labelOfAddress;
JButton okBtn;//确定按钮
URL url;//URL对象