// MessageManager.java// MessageManger is an interface for objects capable of managing// communications with a message server.package com.deitel.messenger;public interface MessageManager {         // connect to message server and route incoming messages   // to given MessageListener   public void connect( MessageListener listener );      // disconnect from message server and stop routing   // incoming messages to given MessageListener   public void disconnect( MessageListener listener );      // send message to message server   public void sendMessage( String from, String message );  }/************************************************************************** * (C) Copyright 1992-2003 by Deitel & Associates, Inc. and               * * Prentice Hall. All Rights Reserved.                                    * *                                                                        * * DISCLAIMER: The authors and publisher of this book have used their     * * best efforts in preparing the book. These efforts include the          * * development, research, and testing of the theories and programs        * * to determine their effectiveness. The authors and publisher make       * * no warranty of any kind, expressed or implied, with regard to these    * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or       * * consequential damages in connection with, or arising out of, the       * * furnishing, performance, or use of these programs.                     * *************************************************************************/