Android實現MediaPlayer與Http Proxy結合使用示例（一）

本文將會教大家如何實現一個簡單的代理服務器(僅支持Http Get)，與Android的MediaPlayer結合，從而可以擴展出“播放 防盜鏈的媒體文件”，“邊播放邊保存”等的功能。

       本文的代碼可以到這裡下載：http://download.csdn.net/detail/hellogv/4047134，代碼分為兩個工程：

1. J2SE工程：HttpGetProxy，在PC上實現簡單的代理服務器，核心類是HttpGetProxy.java，非常容易使用，這裡就不唠叨了直接貼出運行效果圖：
2. Android工程：本文重點，必須唠叨一下。MediaPlayer播放網絡音頻與HttpGetProxy.java結合，通過代理服務器播放網絡音頻。

   接下來貼出HttpGetProxy.java的原理圖：

 接下來貼出HttpGetProxy.java的源碼：

通過RemoteSocket的out_remoteSocket可以訪問防盜鏈資源，HttpGetProxy通過2個線程來實現轉發，可以在兩個線程內實現保存的功能。

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) { 
 
        // --------建立代理中轉服務器-----------// 
        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(); 
        } 
    } 
 
    /** 
     * 結束時，清除所有資源 
     */ 
    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); 
 
        // --------連接目標服務器---------// 
        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，並轉發到遠程服務器 
         */ 
        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改為遠程ip---// 
                            buffer = buffer.replace(LOCAL_IP_ADDRESS,remoteIPAddress); 
                            System.out.println("已經替換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(); 
 
        /** 
         * 接收遠程服務器reply，並轉發到本地客戶端 
         */ 
        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(); 
    } 
}