SmiTest


1   /*
2   * MobiliTools: an implementation of the Object Management Group's
3   * Mobile Agent Facility specification.
4   * Copyright (C) 2003 France Telecom R&D
5   *
6   * This library is free software; you can redistribute it and/or
7   * modify it under the terms of the GNU Lesser General Public
8   * License as published by the Free Software Foundation; either
9   * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  *
20  * MobiliTools $Name:  $
21  *
22  * Contact: bruno.dillenseger@francetelecom.com
23  *
24  * Authors: Bruno Dillenseger
25  */
26  
27  
28  import org.objectweb.mobilitools.smi.api.Agency;
29  import org.objectweb.mobilitools.smi.api.*;
30  import java.applet.*;
31  import java.io.*;
32  
33  
34  /**
35   * MobiliTools $Name:  $, $Id: SmiTest.java,v 1.1.1.1 2003/03/28 14:47:58 dillense Exp $
36   * <P>
37   * This example class shows MobileObject lifecycle through a console-based user interaction, as well as resource loading.
38   * The easiest way to use this example is to use GUI-enabled agencies.
39   * <BR>Note that this agent has no autonomous activity.
40   */
41  public class SmiTest implements MobileObject
42  {
43      /** display-friendly name, set once for all at creation */
44      String   my_name;
45      /** true if the agent is currently active, false if it is suspended */
46      boolean running;
47      /** reference to current host agency, set after each move - must be transient because non-serializable */
48      transient Agency my_agency;
49  
50  
51      /**
52       * Default constructor is invoked when no argument is provided for agent creation.
53       */
54      public SmiTest()
55      {
56          System.out.println("SmiTest default constructor");
57      }
58  
59  
60      /**
61       * (Generic) Example of specific constructor. Displays the argument provided
62       * for agent creation.
63       */
64      public SmiTest(Object   arg)
65      {
66          System.out.println("SmiTest constructor with argument " + arg);
67      }
68  
69  
70      //////////////////////////////////////////////
71      // implementation of MobileObject interface //
72      //////////////////////////////////////////////
73  
74  
75      /**
76       * Displays a message and plays a sound on agent creation. Aks confirmation of creation.
77       * Answer 'y' or 'n' to respectively accept or deny agent creation. If creation is denied,
78       * the creation-caller gets an exception.
79       */
80      public void afterBirth(AgentSystem agency, AgentInfo entry, Object   argument)
81          throws BadOperation
82      {
83          my_agency = (Agency)agency;
84          my_name = new String  (entry.getName().identity());
85          System.out.println("agent " + (new Name(entry.getName().getStringRepresentation())).toString());
86          running = true;
87          playSound("12312.au");
88          if (! confirm(my_name + ".afterBirth() is OK ([y]/n)?", true))
89          {
90              throw new BadOperation(BadOperation.REJECTED, "Agent creation is denied.");
91          }
92      }
93  
94  
95      /**
96       * Asks confirmation before moving. Answer 'y' or 'n' in the console to respectively
97       * confirm or abort the move. In case you abort, an exception is raised, the agent
98       * is not serialized, and the move-caller gets an exception.
99       */
100     public void beforeMove(Location location, String   place)
101         throws BadOperation
102     {
103         if (! confirm(
104             my_name
105             + ".beforeMove("
106             + location.getRegion() + " "
107             + location.getAgency() + ", "
108             + place + ") is OK ([y]/n)?",
109             true))
110         {
111             throw new BadOperation(BadOperation.REJECTED, "Agent move is denied.");
112         }
113     }
114 
115 
116     /**
117      * Plays a sound and asks installation confirmation after deserialization in the target agency.
118      * Answer 'y' or 'n' to respectively accept or deny installation. Denying will drop the agent copy
119      * in the target agency and invoke <code>afterMoveFailed()</code> on the agent in source agency.
120      */
121     public void afterMove(AgentSystem agency, Location location, String   place)
122         throws BadOperation
123     {
124         my_agency = (Agency)agency;
125         playSound("12312.au");
126         if (!confirm(
127             my_name
128             + ".afterMove("
129             + location.getRegion() + " "
130             + location.getAgency() + ", "
131             + place + ") is OK ([y]/n)?",
132             true))
133         {
134             throw new BadOperation(BadOperation.REJECTED, "Agent re-installation is denied.");
135         }
136     }
137 
138 
139     /**
140      * Plays a sound and displays a message in the source agency after the agent has been serialized
141      * but its installation in the target agency has failed (probably rejected by the agent itself)
142      */
143     public void afterMoveFailed(
144         Location location,
145         String   place,
146         int reason,
147         String   message)
148     {
149         playSound("12312.au");
150         System.out.println(
151             my_name
152             + ".afterMoveFailed("
153             + location.getRegion() + " "
154             + location.getAgency() + ", "
155             + place + ")");
156         System.out.println("code " + String.valueOf(reason) + ": " + message);
157     }
158 
159 
160     /**
161      * Displays a message on host agency shutdown
162      */
163     public void beforeShutdown()
164     {
165         System.out.println(my_name + ".beforeShutdown()");
166     }
167 
168 
169     /**
170      * Displays a message on termination
171      */
172     public void beforeDeath()
173     {
174         System.out.println(my_name + ".beforeDeath()");
175     }
176 
177 
178     /**
179      * Displays an acknowledgement message on agent activity resumption if and only if it was suspended,
180      * otherwise the resume-caller gets an exception.
181      */
182     public void beforeResume()
183         throws BadOperation
184     {
185         if (running)
186         {
187             throw new BadOperation(BadOperation.RUNNING, "Agent activity was already running.");
188         }
189         running = true;
190         System.out.println(my_name + ".resume()");
191     }
192 
193 
194     /**
195      * Displays an acknowledgement message on agent activity suspension if and only if it was active,
196      * otherwise the suspend-caller gets an exception.
197      */
198     public void beforeSuspend()
199         throws BadOperation
200     {
201         if (! running)
202         {
203             throw new BadOperation(BadOperation.RUNNING, "Agent activity was already suspended.");
204         }
205         running = false;
206         System.out.println(my_name + ".suspend()");
207     }
208 
209 
210     /////////////////////////
211     // own support methods //
212     /////////////////////////
213 
214 
215     /**
216      * Displays a message and reads a confirmation ('y' or 'n' whatever upper or lower case)
217      * in the attached console/terminal
218      * @param message confirmation question to be displayed
219      * @param defaultYes default answer (i.e. when neither 'y' nor 'n' is entered)
220      * @return true if the user answered 'y', false if the user answered 'n', defaultYes otherwise.
221      */
222     boolean confirm(String   message, boolean defaultYes)
223     {
224         try
225         {
226             System.out.print(message);
227             String   reply = (new BufferedReader(new InputStreamReader(System.in))).readLine();
228             return reply.equalsIgnoreCase("y") || (defaultYes && ! reply.equalsIgnoreCase("n"));
229         }
230         catch (IOException e)
231         {
232             e.printStackTrace();
233         }
234         return defaultYes;
235     }
236 
237 
238     /**
239      * Loads a sound designated by the provided resource name using the agent's class classloader and plays it.
240      * @param resourcename the name of the resource (should be an audio file)
241      */
242     void playSound(String   resourcename)
243     {
244         try
245         {
246             Applet.newAudioClip(getClass().getClassLoader().getResource(resourcename)).play();
247         }
248         catch (Exception   ex)
249         {
250             System.err.println("could not load and play audio resource " + resourcename + "\n" + ex);
251 
252         }
253     }
254 }
255
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