httptunnelservlet.java

java实现的代理程序 socket 编程实现的http 和socket 代理程序

package javatunnel;

import java.io.*;
import java.net.*;
import java.util.*;

import javax.servlet.http.*;

/**
 *
 *JavaTunnel
 *
 *Copyright (C) 2002 Andr閟 Ederra
 *
 *This program is free software; you can redistribute it and/or
 *modify it under the terms of the GNU General Public License
 *as published by the Free Software Foundation; either version 2
 *of the License, or (at your option) any later version.
 *
 *This program is distributed in the hope that it will be useful,
 *but WITHOUT ANY WARRANTY; without even the implied warranty of
 *MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *GNU General Public License for more details.
 *
 *You should have received a copy of the GNU General Public License
 *along with this program; if not, write to the Free Software
 *Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/
public class HTTPTunnelServlet extends HttpServlet {

	static String controlHeader = "TunnelControl";
	static String CONNECT = "CONNECT";
	static String IN = "IN";
	static String OUT = "OUT";
	static String ERROR = "ERROR";

	HashMap connectionList = new HashMap();
	int connectionCount = 0;
	static final int BUFFERSIZE = 1024 * 10;

	private static final int WAITCYCLE = 200;

	public void init() {
		System.out.println("JavaTunnel Servlet UP!");
	}
	/*public void service(ServletRequest req, ServletResponse resp) {
		System.out.println("service");
		System.out.println(req.getProtocol());
		System.out.println(req);
		Enumeration enum = req.getAttributeNames();
		while (enum.hasMoreElements()) {
			System.out.println(enum.nextElement());
		}
		try {
			ServletInputStream in = req.getInputStream();
			byte[] buffer = new byte[BUFFERSIZE];
			int offset = 0;
			int n = 0;
			while (n != -1) {
				System.out.println("pre readline");
				n = in.readLine(buffer, offset, BUFFERSIZE);
				System.out.println("post readline");
				System.out.println(new String(buffer));
				offset += n;
			}
		} catch (IOException ioe) {
			ioe.printStackTrace();
		}
	}*/
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) {

		executeCommand(req, resp);
	}
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) {

		executeCommand(req, resp);
	}
	private void executeCommand(
		HttpServletRequest req,
		HttpServletResponse resp) {

		StringTokenizer tokenizer;
		String control = req.getHeader(controlHeader);
		if (control != null) {
			tokenizer = new StringTokenizer(control);
			//Process the command
			String[] commands = new String[tokenizer.countTokens()];
			int i = 0;
			while (tokenizer.hasMoreElements()) {
				commands[i] = tokenizer.nextToken();
				i++;
			}

			if (commands[0].equals(CONNECT)) {

				String connection =
					createConnection(
						commands[1],
						Integer.parseInt(commands[2]));
				resp.setHeader(controlHeader, CONNECT + " " + connection);

			} else if (commands[0].equals(IN)) {
				handleIncomingData(commands[1], req, resp);

			} else if (commands[0].equals(OUT)) {

				handleOutcomingData(commands[1], req, resp);
			}
		} else {
			try {
				resp.sendError(HttpServletResponse.SC_BAD_REQUEST);
			} catch (IOException ioe) {
				System.out.println(ioe);
				ioe.printStackTrace();
			}
		}
	}
	private String createConnection(String host, int port) {
		try {
			Socket remoteSocket = new Socket(host, port);

			synchronized (this) {
				connectionCount++;
				connectionList.put(
					String.valueOf(connectionCount),
					remoteSocket);
				return String.valueOf(connectionCount);
			}

		} catch (Exception e) {
			System.out.println(e);
			e.printStackTrace();
			return null;
		}

	}
	private void handleOutcomingData(
		String ticket,
		HttpServletRequest req,
		HttpServletResponse resp) {
		Socket outSocket = (Socket) connectionList.get(ticket);
		if (outSocket != null) {
			try {
				OutputStream outputStream = outSocket.getOutputStream();

				byte[] buffer = new byte[BUFFERSIZE];
				int n = 0;
				while (n != -1) {
					n = req.getInputStream().read(buffer);
					if (n != -1) {
						outputStream.write(buffer, 0, n);
						outputStream.flush();
					}
				}

				OutputStream responseStream = resp.getOutputStream();

				responseStream.write("OK".getBytes());

				responseStream.flush();
				responseStream.close();
			} catch (Exception e) {
				System.out.println(e);
				e.printStackTrace();
			}

		} else {
			try {
				OutputStream responseStream = resp.getOutputStream();

				responseStream.write("ERROR".getBytes());

				responseStream.flush();
				responseStream.close();
			} catch (Exception e) {
				System.out.println(e);
				e.printStackTrace();
			}
		}
	}

	private void handleIncomingData(
		String ticket,
		HttpServletRequest req,
		HttpServletResponse resp) {
		Socket inSocket = (Socket) connectionList.get(ticket);

		if (inSocket != null) {
			try {
				InputStream inputStream = inSocket.getInputStream();
				byte[] buffer = new byte[BUFFERSIZE];

				int n;
				n = inputStream.read(buffer);
				while (n == -1) {
					try {
						Thread.sleep(WAITCYCLE);
					} catch (InterruptedException ie) {
						ie.printStackTrace();
					}
					n = inputStream.read(buffer);
				}

				resp.getOutputStream().write(buffer, 0, n);
				resp.getOutputStream().flush();
				resp.getOutputStream().close();

				//}

			} catch (Exception e) {
				System.out.println(e);
				e.printStackTrace();
			}
		}
	}

}