class Serwer extends Thread {
    protected int port;

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

    @Override public void run() {
        ServerSocket serwer = null;
        try {
            serwer = new ServerSocket(port);
        } catch (IOException e) {}

        ServerThread t;
        while(true) {
            try {
                Socket channel = serwer.accept();
                t = new ServerThread(channel);
                t.start();
            } catch (IOException e) {}
        }
    }
}
class ServerThread extends Thread {
    protected Socket channel;
    protected PrintWriter out;
    public static BufferedReader in = null;


    public ServerThread(Socket s) {
        channel = s;
        try {
            in = new BufferedReader(new InputStreamReader(s.getInputStream()));
            out = new PrintWriter(s.getOutputStream(), true);
        } catch (Exception e) {}
    }

    public void wyslij(String wiadomosc) {
        try {

            out.println(wiadomosc);
            out.flush();
            } catch (Exception e) {}
    }

    public String odbierz() {
        String wiadomosc="";
        try {
                wiadomosc = in.readLine();

        } catch (Exception e) {}

        return wiadomosc;
    }
    protected void rozlacz() {
        try {
            channel.close();
        } catch(Exception ex) {}
    }




    @Override public void run() {
        String wiadomosc;
        while (channel.isConnected()) {
            wiadomosc = odbierz();
            System.out.print(wiadomosc);
                if (wiadomosc!="") {
                    wyslij(wiadomosc);
                        wiadomosc="";
                }
        }
    }
}
public class SerwerTest{
    public static void main(String[] args){
        Serwer serwer = new Serwer(8000);
        serwer.start();
    }

}