import java.io.*;
import java.net.*;
/**
*
* @author jcgonzalez.com
*
*/
public class ProxyMultiThread {
public static void main(String[] args) {
try {
if (args.length != 3)
throw new IllegalArgumentException("insuficient arguments");
// and the local port that we listen for connections on
String host = args[0];
int remoteport = Integer.parseInt(args[1]);
int localport = Integer.parseInt(args[2]);
// Print a start-up message
System.out.println("Starting proxy for " + host + ":" + remoteport
+ " on port " + localport);
ServerSocket server = new ServerSocket(localport);
while (true) {
new ThreadProxy(server.accept(), host, remoteport);
}
} catch (Exception e) {
System.err.println(e);
System.err.println("Usage: java ProxyMultiThread "
+ "<host> <remoteport> <localport>");
}
}
}
/**
* Handles a socket connection to the proxy server from the client and uses 2
* threads to proxy between server and client
*
* @author jcgonzalez.com
*
*/
class ThreadProxy extends Thread {
private Socket sClient;
private final String SERVER_URL;
private final int SERVER_PORT;
ThreadProxy(Socket sClient, String ServerUrl, int ServerPort) {
this.SERVER_URL = ServerUrl;
this.SERVER_PORT = ServerPort;
this.sClient = sClient;
this.start();
}
@Override
public void run() {
try {
final byte[] request = new byte[1024];
byte[] reply = new byte[4096];
final InputStream inFromClient = sClient.getInputStream();
final OutputStream outToClient = sClient.getOutputStream();
Socket client = null, server = null;
// connects a socket to the server
try {
server = new Socket(SERVER_URL, SERVER_PORT);
} catch (IOException e) {
PrintWriter out = new PrintWriter(new OutputStreamWriter(
outToClient));
out.flush();
throw new RuntimeException(e);
}
// a new thread to manage streams from server to client (DOWNLOAD)
final InputStream inFromServer = server.getInputStream();
final OutputStream outToServer = server.getOutputStream();
// a new thread for uploading to the server
new Thread() {
public void run() {
int bytes_read;
try {
while ((bytes_read = inFromClient.read(request)) != -1) {
outToServer.write(request, 0, bytes_read);
outToServer.flush();
//TODO CREATE YOUR LOGIC HERE
}
} catch (IOException e) {
}
try {
outToServer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}.start();
// current thread manages streams from server to client (DOWNLOAD)
int bytes_read;
try {
while ((bytes_read = inFromServer.read(reply)) != -1) {
outToClient.write(reply, 0, bytes_read);
outToClient.flush();
//TODO CREATE YOUR LOGIC HERE
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (server != null)
server.close();
if (client != null)
client.close();
} catch (IOException e) {
e.printStackTrace();
}
}
outToClient.close();
sClient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
