Message


1   /*
2    * Copyright (c) 2004, Bruce Lowery
3    * All rights reserved.
4    *
5    * Redistribution and use in source and binary forms, with or without
6    * modification, are permitted provided that the following conditions are met:
7    *
8    *    - Redistributions of source code must retain the above copyright notice,
9    *      this list of conditions and the following disclaimer.
10   *    - Redistributions in binary form must reproduce the above copyright
11   *      notice, this list of conditions and the following disclaimer in the
12   *      documentation and/or other materials provided with the distribution.
13   *    - Neither the name of JEGG nor the names of its contributors may be used
14   *      to endorse or promote products derived from this software without
15   *      specific prior written permission.
16   *
17   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27   * POSSIBILITY OF SUCH DAMAGE.
28   */
29  package jegg;
30  
31  import jegg.impl.Priority;
32  
33  /**
34   * Used to wrap an application message that is being sent from one egg to another.
35   * <p>
36   * The Message instance not wraps the sending egg's concrete message object, but
37   * also holds a reference to the sending egg's own message port and the
38   * priority of the message. 
39   * <p>
40   * An egg can use a {@link jegg.EggContext.ceateMessage(Object)
41   * EggContext.createMessage()}, to wrap an application message before writing 
42   * it to a message port.  This can save unnecessary object creation when the
43   * same message will be sent to a list of ports.
44   */
45  public interface Message
46  {
47      /**
48       * Return the port of the egg that sent this message.
49       * @return the sending egg's message port.
50       */
51      Port getFrom();
52      
53      /**
54       * Return the application message.
55       * 
56       * @return the application message wrapped by this JEgg message.
57       */
58      Object   getMessage();
59      
60      /**
61       * Return the dispatch priority of this message.
62       * @return dispatch priority.
63       */
64      Priority getPriority();
65  }
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags