webviewer.java

java编程开发技巧与实例的编译测试通过的所有例程

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

public class WebViewer extends Frame implements ActionListener
{
	private TextField address	=	new TextField();
	private TextArea display	=	new TextArea();
	private Button go			=	new Button("View Page");
	private class WindowCloser extends WindowAdapter
	{
		public void windowClosing(WindowEvent we)
		{
			System.exit(0);
		}
	}
	public WebViewer()
	{
		super("Web Viewer Lite");
		Panel north	=	new Panel();
		north.setLayout(new BorderLayout());
		north.add("West", new Label("URL:"));
		north.add("Center",address);
		north.add("East", go);
		go.addActionListener(this);
		Panel center	=	new Panel();
		setLayout(new BorderLayout());
		add("North", north);
		add("Center", display);
		addWindowListener(new WindowCloser());
		validate();
		pack();
		setLocationRelativeTo(this);
		setVisible(true);
	}
	public void actionPerformed(ActionEvent ae)
	{
		if (ae.getSource() == go)
			showURL(address.getText());
	}
	public void showURL(String address)
	{
		try
		{
			setCursor(new Cursor(Cursor.WAIT_CURSOR));
			URL url		=	new URL(address);
			String host	=	url.getHost();
			int port	=	url.getPort();
			if (port <= 0)
				port = 80;
			WebPage page	=	new WebPage(host, port, url.getFile());
			display.setText(page.getContent());
		}
		catch	(MalformedURLException murle)
		{
			display.setText("Invalid URL: " + address);
		}
		finally
		{
			setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
		}
	}
	public static void main(String args[])
	{
		WebViewer viewer = new WebViewer();
	}
}