public void sendMessage(String receivers, String msg, String sender) {
   String messageString = "MESSAGE#" + sender + "#" + msg;
   String[] receiversarray = receivers.split(",");
   if (receiversarray.length == 1) {
     String receiver = receiversarray[0];
     if (receiver.equals("*")) {
       for (Handler handler : handlers.values()) {
         handler.sendMessage(messageString);
         Logger.getLogger(EchoServer.class.getName())
             .log(
                 Level.INFO,
                 handler.getUsername() + " Sent a message to all: " + messageString,
                 new Object[] {handler.getUsername()});
       }
     } else {
       Handler handler = (Handler) handlers.get(receiver);
       handler.sendMessage(messageString);
       Logger.getLogger(EchoServer.class.getName())
           .log(
               Level.INFO,
               handler.getUsername() + " Sent a message: " + messageString + " to: " + receiver,
               new Object[] {handler.getUsername()});
     }
   }
 }