Java APIs

Greetings,

I am having trouble writing a simple http proxy server. The proxy works quite well, except for a java.net.SocketException (broken pipe) that emerges quite randomly, especially when the traffic is heavier. What could be causing this? I have met lots of cases where firewalls and NAT issues were involved, but for me this is not the case.

I wonder if this has anything to do with the headers in the request the browser sends to the proxy, since I had to change the network.http.proxy.keep-alive (I set it to false) preference of the browser (firefox) to avoid non-closing connections. Is there possibly another preference that has such an impact on my proxy?

The proxy code follows.

package proxy;

import java.net.*;
import java.util.*;
import java.io.*;

public class Proxy implements Runnable {
    private int port;

    public Proxy(int port) {
        this.port = port;
    }

    public void run() {
        ServerSocket serverSocket;
        try {
            serverSocket = new ServerSocket(port);
            serverSocket.setSoTimeout(0);

            ExecutorService threadExecutor = Executors.newFixedThreadPool(200);

            while (true) {
                threadExecutor.execute(new ConnectionHandler(serverSocket.accept()));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        int port = 66666;
        Proxy me = new Proxy(port);
        me.run();
    }
}

class ConnectionHandler implements Runnable {
    private Socket peerSocket;

    public ConnectionHandler(Socket peerSocket) throws SocketException {
        this.peerSocket = peerSocket;
    }

    public void run() {
        HttpRequest request; /* utility class for the http request, not important */
        Socket remoteSocket;
        try {
            byte[] req = new byte[10240];
            int bytesRead;
            InputStream peerIn = peerSocket.getInputStream();
            bytesRead = peerIn.read(req);
            request = new HttpRequest(new String(req, 0, bytesRead));

            URL url = request.getRequestUrl(); /*returns the remote host's url from the request */
            int port = url.getPort();
            if (port == -1) {
                port = 80;
            }
            remoteSocket = new Socket(url.getHost(), port);

            OutputStream out = remoteSocket.getOutputStream();
            InputStream in = remoteSocket.getInputStream();

            //write request to remote host's socket
            out.write(request.getRequest().getBytes());
            out.flush();

            OutputStream peerOut = peerSocket.getOutputStream();

            int bytes;
            byte response[] = new byte[32768];
            while ((bytes = in.read(response)) > 0) {
                peerOut.write(response, 0, bytes); /* The exception is thrown here */
                peerOut.flush();
            }

            out.close();
            in.close();
            peerOut.close();

            peerSocket.close();
            remoteSocket.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

The exception's stack trace is

java.net.SocketException: Broken pipe
	at java.net.SocketOutputStream.socketWrite0(Native Method)
	at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
	at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
	at proxy.ConnectionHandler.run(ConnectionHandler.java:72) /* This line is marked above */
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
	at java.lang.Thread.run(Thread.java:619)