本文来自http://blog.csdn.net/hellogv/ ，引用必须注明出处！      

       最近半年都忙着Android TV项目，在春节假期才有时间写点东西。先在这里给大家拜个年，祝大家龙年快乐...

       直接进入主题：本文将会教大家如何实现一个简单的代理服务器(仅支持Http Get)，与Android的MediaPlayer结合，从而可以扩展出“播放 防盗链的媒体文件”，“边播放边保存”等的功能。

       本文的代码可以到这里下载：http://download.csdn.net/detail/hellogv/4047134，代码分为两个工程：

1. J2SE工程：HttpGetProxy，在PC上实现简单的代理服务器，核心类是HttpGetProxy.java，非常容易使用，这里就不唠叨了直接贴出运行效果图：
2. Android工程：本文重点，必须唠叨一下。MediaPlayer播放网络音频（http://blog.csdn.net/hellogv/article/details/6406732）与HttpGetProxy.java结合，通过代理服务器播放网络音频。

   接下来贴出HttpGetProxy.java的原理图：

 接下来贴出HttpGetProxy.java的源码：

通过RemoteSocket的out_remoteSocket可以访问防盗链资源，HttpGetProxy通过2个线程来实现转发，可以在两个线程内实现保存的功能。

package com.musicplayer;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.UnknownHostException;

import android.util.Log;

public class HttpGetProxy {
	final private String LOCAL_IP_ADDRESS = "127.0.0.1";
	final private int HTTP_PORT = 80;

	private ServerSocket localServer = null;
	private Socket localSocket = null;
	private Socket remoteSocket = null;
	private String remoteIPAddress;

	private InputStream in_remoteSocket;
	private OutputStream out_remoteSocket;
	private InputStream in_localSocket;
	private OutputStream out_localSocket;
	
	private interface OnFinishListener {
		void onFinishListener();
	}
	
	public HttpGetProxy(int localport) {

		// --------建立代理中转服务器-----------//
		try {
			localServer = new ServerSocket(localport, 1,
					InetAddress.getByName(LOCAL_IP_ADDRESS));
		} catch (UnknownHostException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	/**
	 * 结束时，清除所有资源
	 */
	private OnFinishListener finishListener =new OnFinishListener(){

		@Override
		public void onFinishListener() {
			System.out.println("..........release all..........");
			Log.e("---->","..........release all..........");
			try {
				in_localSocket.close();
				out_remoteSocket.close();
				
				in_remoteSocket.close();
				out_localSocket.close();
				
				localSocket.close();
				remoteSocket.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	};
	
	public void startProxy(String remoteIpAddr) throws IOException {
		remoteIPAddress = remoteIpAddr;
		SocketAddress address = new InetSocketAddress(remoteIPAddress,HTTP_PORT);

		// --------连接目标服务器---------//
		remoteSocket = new Socket();
		remoteSocket.connect(address);
		System.out.println("..........remote Server connected..........");
		Log.e("---->","..........remote Server connected..........");
		in_remoteSocket = remoteSocket.getInputStream();
		out_remoteSocket = remoteSocket.getOutputStream();
		System.out.println("..........init remote Server I/O..........");
		/**
		 * 接收本地request，并转发到远程服务器
		 */
		new Thread() {
			public void run() {
				int bytes_read;
				byte[] local_request = new byte[5120];
				try {
					// 本地Socket
					localSocket = localServer.accept();
					System.out.println("..........localSocket connected..........");
					Log.e("---->","..........localSocket connected..........");
					in_localSocket = localSocket.getInputStream();
					out_localSocket = localSocket.getOutputStream();

					System.out.println("..........init local Socket I/O..........");
					Log.e("---->","..........init local Socket I/O..........");
					String buffer = "";
					while ((bytes_read = in_localSocket.read(local_request)) != -1) {
						String str = new String(local_request);
						System.out.println("localSocket     " + str);
						Log.e("localSocket---->",str);
						buffer = buffer + str;
						if (buffer.contains("GET")
								&& buffer.contains("\r\n\r\n")) {
							//---把request中的本地ip改为远程ip---//
							buffer = buffer.replace(LOCAL_IP_ADDRESS,remoteIPAddress);
							System.out.println("已经替换IP");
							out_remoteSocket.write(buffer.getBytes());
							out_remoteSocket.flush();
							continue;
						} else{
							out_remoteSocket.write(buffer.getBytes());
							out_remoteSocket.flush();
						}
					}
					System.out.println("..........local finish receive...........");
					Log.e("---->","..........local finish receive..........");
					finishListener.onFinishListener();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}.start();

		/**
		 * 接收远程服务器reply，并转发到本地客户端
		 */
		new Thread() {
			public void run() {
				int bytes_read;
				byte[] remote_reply = new byte[5120];
				try {
					System.out.println("..........remote start to receive...........");
					Log.e("---->","..........remote start to receive..........");
					while ((bytes_read = in_remoteSocket.read(remote_reply)) != -1) {
						
						//System.out.println("remoteSocket     " + remote_reply.length);
						//System.out.println("remoteSocket     " + new String(remote_reply));
						out_localSocket.write(remote_reply, 0, bytes_read);
						out_localSocket.flush();
					}
					System.out.println("..........remote finish receive...........");
					Log.e("---->","..........remote finish receive..........");
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}.start();
	}
}