download_html.java

Java程序设计实验与实训源代码经典的JAVA学习教材

import java.io.*;
import java.net.*;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class Download_html extends Applet
{
	TextField tfURL;
	TextArea taContext;
	Label lbMsg;

	public void init()
	{
		setLayout(new BorderLayout());
		tfURL = new TextField("http://localhost/");
		Button btGet = new Button("DownLoad");
		taContext = new TextArea(25,6);
		lbMsg = new Label("                                   ");
		Panel panel = new Panel();
		panel.add(tfURL);
		panel.add(btGet);
		btGet.addActionListener(new GetButtonActionListener());
		add(panel,BorderLayout.NORTH);
		add(taContext,BorderLayout.CENTER);
		add(lbMsg,BorderLayout.SOUTH);
	}

	class GetButtonActionListener implements ActionListener
	{
		public void actionPerformed( ActionEvent event ) 
		{
			try
			{
				URL 
					url = new URL(tfURL.getText());
				URLConnection 
					connection = url.openConnection();
				connection.setDoOutput(true);
				BufferedReader in = 
					new BufferedReader(
						new InputStreamReader(
							connection.getInputStream()));
				String inputLine;
				while ((inputLine = in.readLine()) != null)
				{
					taContext.append(inputLine + "\n");
					System.out.println(inputLine);
				}
				in.close();
			}
			catch(IOException e)
			{
				lbMsg.setText(e.toString());
			}
	    }
	}
 
	public static void main(String[] args)
	{
		Download_html applet = new Download_html();
		Frame aFrame = new Frame("DownLoadWebPage");
		// 增加windows事件处理，用来推出程序
		aFrame.addWindowListener(
			new WindowAdapter() 
			{
				public void windowClosing(WindowEvent e) 
				{
		          System.exit(0);
				}
			});
		aFrame.add(applet, BorderLayout.CENTER);
		aFrame.setSize(500,500);
		applet.init();
		applet.start();
		aFrame.setVisible(true);
	}
}