// Learning Processing
  // Daniel Shiffman
  // http://www.learningprocessing.com
  
  // Example 19-6: Multi-user server
  
  // Import the net libraries
  import processing.net.*;
  
  // Declare a server
  Server server;
  
  PFont f;
  String incomingMessage = "";
  
  void setup() {
    size(400,200);
    
    // Create the Server on port 5204
    server = new Server(this, 5204);
    f = createFont("Arial",20,true);
  }
  
  void draw() {
    background(255);
    
    // Display rectangle with new message color
    fill(0);
    textFont(f);
    textAlign(CENTER);
    text(incomingMessage,width/2,height/2);
    
    // If a client is available, we will find out
    // If there is no client, it will be"null"
    Client client = server.available();
    
    // We should only proceed if the client is not null
    if (client != null) {
      // Receive the message
      incomingMessage = client.readStringUntil('*'); 
      // Print to Processing message window
      println( "Client says:" + incomingMessage);
      // Write message back out (note this goes to ALL clients)
      server.write(incomingMessage);
    }
  }
  
  // The serverEvent function is called whenever a new client connects.
  void serverEvent(Server server, Client client) {
    incomingMessage = "A new client has connected:" + client.ip();
    println(incomingMessage);
  }