ClientHandler

package Chat;


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

public class ClientHandler implements Runnable {
  Socket client;
  String username;
  Server server;

  //Konstruktor
  public ClientHandler(Socket client, Server server, String username){
    this.client = client;
    this.username = username;
    this.server = server;
  }

  //Methode, um den Username spter zurckzugeben
  public String getUsername() {
    return username;
  }

  //Runnable Methode der Klasse Clienthandler
  @Override
  public void run() {

    String text;

    try {
      //reader & writer
      BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
      BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));

      while (client.isConnected()) {
        if (this.client.getInputStream().available() > 0) {
          text = reader.readLine();
          System.out.println(username + ": " + text);
          final String msg = text;
          String temp = "";
          if(text != null) {
            //an einzelne Personen mit '@' schreiben

            if (text.charAt(0) == '@') {                                                         //Wenn die Nachricht '@' beinhaltet
              for (int i = 0; ' ' != text.charAt(i); i++) {                                      //neuen String erzeugen  -> nur Username mit '@' ohne Nachricht
                temp = temp + text.charAt(i);
              }
              for (int j = 0; j < this.server.getUser().size(); ++j) {
                if (temp.equalsIgnoreCase("@" + this.server.getUser().get(j).getUsername())) {   //Username in ArrayList suchen -> wenn vorhanden, dann nur an diese Person schreiben
                  this.server.getUser().get(j).sendMessage(msg, username);                       //Nachricht senden mit Aufruf der sendMessage-Methode
                }
              }
            } else {                                                                             //Wenn die Nachricht KEIN '@' beinhaltet
              for(int x = 0;x < this.server.user.size(); x++){
                if(this.server.user.get(x).getUsername() != username) {
                  this.server.user.get(x).sendMessage(msg, username);
                }
              }
            }
          }


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

  //Senden der eingegeben Nachricht inkl. Username
  public void sendMessage(String msg, String username){
    try{
      //writer
      BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));

      //Nachricht mit Username schreiben
      writer.write( username + ": " + msg + "\n");
      writer.flush();

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