public static void main(String[] args) throws IOException {
        System.out.println("The Processing server handles source connection on port 7007 and sink connections on port 7008");
        //source socket
        final ServerSocket source_Socket = new ServerSocket(7007);
        //sink socket
        final ServerSocket sink_Socket = new ServerSocket(7008);
        //listen for incoming source connections
        Thread sourceThread = new Thread(new Runnable() {
            @Override
            public void run() {
                while (listening) {
                    try {
                        processSource(source_Socket.accept());
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        //listen for incoming sink connections
        Thread sinkThread = new Thread(new Runnable() {
            @Override
            public void run() {
                while (listening) {
                    try {
                        processSink(sink_Socket.accept());
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        //start the 2 listening threads for source and sinks
        sourceThread.start();
        sinkThread.start();
    }