import java.io.*; 
 import java.net.*; 
  
 public class HttpProxy extends Thread { 
  
 	private static int TIMEOUT = 50; 
 	private static int RETRIES = 5; 
  
 	private Socket socketClient; 
 	private Socket socketServer; 
  
 	private BufferedReader brClient; 
 	private BufferedWriter bwClient; 
 	private BufferedReader brServer; 
 	private BufferedWriter bwServer; 
  
 	public HttpProxy() { 
  
 	} 
  
 	public HttpProxy(Socket s) { 
 		this.socketClient = s; 
 	} 
  
  
 	@Override 
 	public void run() { 
 		String line; 
 		String host; 
 		int port = 80; 
  
 		try { 
 			socketClient.setSoTimeout(TIMEOUT); 
 			socketClient.setTcpNoDelay(true); 
 			brClient = new BufferedReader(new InputStreamReader(socketClient 
 					.getInputStream())); 
 			line = brClient.readLine(); 
 			host = line; 
  
 			/* 
 			 * get the host and port 
 			 */ 
 			int n; 
 			n = host.indexOf("//"); 
 			if (n != -1) 
 				host = host.substring(n + 2); 
 			n = host.indexOf("/"); 
 			if (n != -1) 
 				host = host.substring(0, n); 
 			n = host.indexOf(":"); 
 			if (n != -1) { 
 				port = Integer.parseInt(host.substring(n + 1)); 
 				host = host.substring(0, n); 
 			} 
  
 			System.out.println("------------------------------->>> request"); 
 			System.out.println(line); 
  
 			/* 
 			 * get the to-server-side socket, try RETRIES times 
 			 */ 
 			int retries = RETRIES; 
 			while (retries-- > 0) { 
 				try { 
 					socketServer = new Socket(host, port); 
 					break; 
 				} catch (Exception ex) {/* not success and retry */ 
 				} 
 			} 
 			if (socketServer != null) { 
 				socketServer.setSoTimeout(TIMEOUT); 
 				socketServer.setTcpNoDelay(true); 
 				bwServer = new BufferedWriter(new OutputStreamWriter( 
 						socketServer.getOutputStream())); 
 			} else { 
 				socketClient.close(); 
 				return; 
 			} 
  
 			bwServer.write(line); 
 			bwServer.flush(); 
  
 			brServer = new BufferedReader(new InputStreamReader(socketServer 
 					.getInputStream())); 
 			bwClient = new BufferedWriter(new OutputStreamWriter(socketClient 
 					.getOutputStream())); 
  
 			pipe(brClient, brServer, bwClient, bwServer); 
 		} catch (UnsupportedEncodingException e) { 
 			e.printStackTrace(); 
 		} catch (IOException e) { 
 			e.printStackTrace(); 
 		} finally { 
 			try { 
 				if (socketClient != null && socketClient.isConnected() 
 						&& !socketClient.isClosed()) 
 					socketClient.close(); 
 				if (socketServer != null && socketServer.isConnected() 
 						&& !socketServer.isClosed()) 
 					socketServer.close(); 
 			} catch (IOException e) { 
 				e.printStackTrace(); 
 			} 
 		} 
  
 		System.out.println(">>>------> thread ends"); 
 	} 
  
 	public void pipe(BufferedReader brClient, BufferedReader brServer, 
 			BufferedWriter bwClient, BufferedWriter bwServer) { 
 		String line; 
  
 		while (true) { 
 			try { 
 				line = brClient.readLine(); 
 				if (line != null) { 
 					System.out.println(line); 
 					bwServer.write(line); 
 					bwServer.flush(); 
 				} else 
 					break; 
 			} catch (Exception e) { 
 			} 
  
 			try { 
 				line = brServer.readLine();	//在这儿一直没有响应，如果不加socketServer.setSoTimeout(TIMEOUT);就会挂起