online-chat-ueb3/src/com/vertsys/ServerThread.java

package com.vertsys;

import java.io.*;
import java.net.Socket;

public class ServerThread extends Server implements Runnable{

    private Socket sock;

    public ServerThread(Socket sock){
        this.sock = sock;
    }

    @Override
    public void run() {
        if (DEBUG_MODE)
            System.out.println("New connection --> New Thread started.");
        if(DEBUG_MODE)
            System.out.println("Send all received messages to new client...");
        try {
            ObjectOutputStream toNewClient = new ObjectOutputStream(sock.getOutputStream());
            toNewClient.writeObject(messages);
        } catch (IOException e) {
            e.printStackTrace();
        }
        while(!sock.isClosed()){
            System.out.println("Still running...");
            this.addMessage();
        }
        if(DEBUG_MODE)
            System.out.println("Socket closed --> Joining Thread...");
    }

    private void addMessage(){
        String newMessage = "";
        try {
            newMessage = readMessage();
        } catch (IOException e) {
            e.printStackTrace();
        }
        if (DEBUG_MODE)
            System.out.println("Add new Message...");
        messages.add(newMessage);
        if(DEBUG_MODE)
            System.out.println(newMessage);
        String finalNewMessage = newMessage;
        clients.forEach(socket -> {
            DataOutputStream outgoing = null;

            try {
                outgoing = new DataOutputStream(socket.getOutputStream());
                outgoing.writeBytes(finalNewMessage + "\n");
            } catch (IOException e) {
                e.printStackTrace();
            }

        });
    }
    private String readMessage() throws IOException {
        BufferedReader incoming = new BufferedReader(new InputStreamReader(sock.getInputStream()));
        return incoming.readLine();
    }
}