JAVA Tunnel

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;



class Repeat extends Thread{

    public Repeat otherRepeat;
    public Scanner rx;
    public PrintWriter tx;

    public Repeat(Socket src,Socket tar) throws IOException{
            rx = new Scanner(src.getInputStream());
            tx = new PrintWriter(tar.getOutputStream());
    }

    public void setOtherRepeat(Repeat others){
        otherRepeat = others;
    }

    public void run(){

        try {

            while(rx.hasNext()){
                tx.print(rx.next());
                tx.flush();
            }

        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                otherRepeat.stop();
                otherRepeat.tx.flush();
                otherRepeat.tx.close();
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
    }
}

class TunnelThread extends Thread{
    Socket src;
    Socket tar;
    Repeat srcR;
    Repeat tarR;

    public TunnelThread(Socket source,Socket target){
        src = source;
        tar = target;
    }

    public void run(){
        try {
            srcR = new Repeat(src, tar);
            tarR = new Repeat(tar, src);
            srcR.setOtherRepeat(tarR);
            tarR.setOtherRepeat(srcR);

            srcR.start();
            tarR.start();

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}

class Listener extends Thread{
    //TreeMap

    ServerSocket listen;
    String targetIP;
    int targetPort;

    public Listener(int localPort,String targetIP,int targetPort) throws IOException{
        listen = new ServerSocket(localPort);
        this.targetIP = targetIP;
        this.targetPort = targetPort;
    }

    public void run(){
        while(true){
            try {
                (new TunnelThread(listen.accept(),new Socket(targetIP,targetPort))).start();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

public class tunnel {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        try {
            Listener li = new Listener(991,"127.0.0.1",17);
            li.start();


//          li.stop();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}