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：
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：
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("
")) {
//---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();
}
}