网页源代码获取

这个小程序的实用性并不大，因为一般的浏览器都支持查看源代码，只是通过这个小程序巩固一下对Url，File，I/O等知识的掌握。

此程序在输入时不再需要加"http://"，直接输www形式的网站地址即可，保存时需要加所保存类型的后缀,如：.html，.txt，.doc等，推荐使用.html。

程序运行后效果：

输入网址后，按“确定”，则会显示出网页的源代码，再按保存，则可选择保存路径保存。

（此小程序运行正确的前提是所使用电脑能上网）

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

import javax.swing.*;

public class UrlConnectionTest {
	public static void main(String[] args) {
		new TestFrame();
	}
}

class TestFrame extends JFrame implements ActionListener, Runnable {

	byte[] b = new byte[118];

	public TestFrame() {

		setVisible(true);
		setTitle("网页源代码获得器");
		setSize(WIDTH, HEIGHT);
		button = new JButton("确定");
		sButton = new JButton("保存");
		text = new JTextField(15);
		area = new JTextArea(12, 12);

		button.addActionListener(this);
		sButton.addActionListener(this);
		thread = new Thread();

		panel = new JPanel();
		panel.add(new JLabel("输入网址："));
		panel.add(text);
		panel.add(button);
		panel.add(sButton);

		Container con = this.getContentPane();
		con.add(panel, BorderLayout.NORTH);
		con.add(new JScrollPane(area), BorderLayout.CENTER);
		saveFD = new FileDialog(this, "保存", FileDialog.SAVE);

		addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				setVisible(false);
				System.exit(0);
			}
		});
	}

	public void actionPerformed(ActionEvent e) {
		if ((!thread.isAlive())) {
			thread = new Thread(this);
		}
		try {
			thread.start();
		} catch (Exception ee) {
			JOptionPane.showMessageDialog(this, "正在获取，请稍后", "提示信息",
					JOptionPane.ERROR_MESSAGE);
		}

		if (e.getSource() == sButton) {
			saveFD.setVisible(true);
			try {
				File f1 = new File(saveFD.getDirectory(), saveFD.getFile());
				BufferedWriter bw = new BufferedWriter(new FileWriter(f1));
				String gt = area.getText();
				bw.write(gt, 0, gt.length());
				bw.flush();
				bw.close();
			} catch (Exception e2) {
				e2.printStackTrace();
			}
		}
	}

	public void run() {
		try {
			int n = -1;
			area.setText(null);
			url = new URL(("http://" + text.getText()).trim());
			InputStream is = url.openStream();
			while (-1 != (n = is.read(b, 0, b.length))) {
				String str = new String(b, 0, n);
				area.append(str);
			}
		} catch (MalformedURLException e1) {
			text.setText("" + e1);
			return;
		} catch (IOException e1) {
			text.setText("" + e1);
			return;
		}
	}

	public static final int WIDTH = 420;
	public static final int HEIGHT = 300;

	private URL url;
	private JButton button;
	private JButton sButton;
	private JTextField text;
	private JTextArea area;
	private Thread thread;
	private JPanel panel;
	private FileDialog saveFD;

}