例11-1.txt

Java大学实用教程 耿祥义编著 课件 PPT

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
class Win extends JFrame 
implements ActionListener,Runnable
{  
   JButton button;
   URL url;
   JTextField text;
   JTextArea area; 
   byte b[]=new byte[118];
   Thread thread;
   public Win()
   {  
      text=new JTextField(20);
      area=new JTextArea(12,12);
      button=new JButton("确定");
      button.addActionListener(this);
      thread=new Thread(this);
      JPanel p=new JPanel();
      p.add(new JLabel("输入网址:"));
      p.add(text); 
      p.add(button);
      Container con=getContentPane();
      con.add(new JScrollPane(area),BorderLayout.CENTER);
      con.add(p,BorderLayout.NORTH);
      setBounds(60,60,360,300);
      setVisible(true);
      validate();
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   }
   public void actionPerformed(ActionEvent e)
   { 
      if(!(thread.isAlive())) 
         thread=new Thread(this);
      try{
           thread.start();
         }
      catch(Exception ee)
         {
            text.setText("我正在读取"+url);
         }
   }
  public void run()
   {
       try {    
                 int n=-1;
                 area.setText(null);
                 url=new URL(text.getText().trim());
                 InputStream in=url.openStream();
                 while((n=in.read(b))!=-1)
                 {
                     String s=new String(b,0,n);
                     area.append(s);    
                 }
            }
          catch(MalformedURLException e1)
           {  
                 text.setText(""+e1);
                 return;
           }
          catch(IOException e1)
           {  
                 text.setText(""+e1);
                 return;
           }  
   }
}
public class Example
{ 
    public static void main(String args[])
    { 
       new Win();
    }
}