Java LoadBalancer - Threaded

JavaLoadBalancer.java

package com.veryamt;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Random;

class Worker implements Runnable {
        private Socket from;
        private Socket to;
        Worker (Socket from, Socket to) {
                this.from = from;
                this.to = to;
        }

        public void run() {
                // TODO Auto-generated method stub
                byte[] buf = new byte[4096];
                int buf_len;
                System.out.format("Redirect from %s to %s\n", from.toString(), to.toString());
                try {
                        while ((buf_len = from.getInputStream().read(buf)) != -1) {
                                to.getOutputStream().write(buf, 0, buf_len);
                        }
                        to.close();
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        // e.printStackTrace();
                }
                System.out.format("Redirect Finished from %s to %s\n", from.toString(), to.toString());
        }

}

public class JavaLoadBalancer {
        private int port;
        private ServerSocket ss;
        private ArrayList<InetSocketAddress> pool;
        private int pool_index = 0;

        public JavaLoadBalancer(int port, ArrayList<InetSocketAddress> pool) {
                this.port = port;
                this.pool = pool;
        }

        /**
         * @param args
         */
        public static void main(String[] args) {
                // TODO Auto-generated method stub
                int port = 8080;
                ArrayList<InetSocketAddress> pool = new ArrayList<InetSocketAddress>();
                pool.add(new InetSocketAddress("192.168.1.10", 80));
                pool.add(new InetSocketAddress("192.168.1.30", 80));
                JavaLoadBalancer jlb = new JavaLoadBalancer(port, pool);
                jlb.start();
        }

        private InetSocketAddress get_random_server() {
                int intex = pool_index % pool.size();
                pool_index += 1;
                return this.pool.get(intex);
        }

        private void handle_client(Socket clientSocket) {
                InetSocketAddress backend = get_random_server();
                System.out.println("Using backend: " + backend.toString());

                Socket backendSocket;
                try {
                        backendSocket = new Socket(backend.getHostName(), backend.getPort());
                } catch (UnknownHostException e1) {
                        System.out.println("Unable to connect backend: " + backend.toString());
                        return;
                } catch (IOException e1) {
                        System.out.println("Unable to connect backend: " + backend.toString());
                        return;
                }
                System.out.println("Connected to backend: " + backendSocket.toString());

                Worker c2b = new Worker(clientSocket, backendSocket);
                Worker b2c = new Worker(backendSocket, clientSocket);

                ArrayList<Thread> threads = new ArrayList<Thread>();
                threads.add(new Thread(c2b));
                threads.add(new Thread(b2c));
                for(Thread thread: threads) {
                        thread.start();
                }
//              for(Thread thread: threads) {
//                      try {
//                              thread.join();
//                      } catch (InterruptedException e) {
//                              // TODO Auto-generated catch block
//                              e.printStackTrace();
//                      }
//              }
        }

        private void start() {
                try {
                        this.ss = new ServerSocket(port);
                        while (true) {
                                Socket clientSocket = this.ss.accept();
                                System.out.println("Accept client: " + clientSocket.toString());
                                handle_client(clientSocket);
                        }
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
        }

}