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1   //----------------------------------------------------------------------
2   // 
3   // PerfectJPattern: "Design patterns are good but components are better!" 
4   // FirstNHandleStrategy.java Copyright (c) 2009 Giovanni Azua Garcia
5   // bravegag@hotmail.com
6   //  
7   // This program is free software; you can redistribute it and/or
8   // modify it under the terms of the GNU General Public License
9   // as published by the Free Software Foundation; either version 3
10  // of the License, or (at your option) any later version.
11  //
12  // This program is distributed in the hope that it will be useful,
13  // but WITHOUT ANY WARRANTY; without even the implied warranty of
14  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  // GNU General Public License for more details.
16  //
17  // You should have received a copy of the GNU General Public License
18  // along with this program; if not, see <http://www.gnu.org/licenses/>.
19  //
20  //----------------------------------------------------------------------
21  package org.perfectjpattern.core.behavioral.chainofresponsibility;
22  
23  import org.perfectjpattern.core.api.behavioral.chainofresponsibility.*;
24  
25  /**
26   * Concrete implementation of <code>IChainStrategy</code> that allows
27   * all <code>IHandler</code> instances in the Chain to handle the given request.
28   * <br/><br/>
29   * <code>AllHandleStrategy</code> is stateless, reentrant and a Singleton 
30   * therefore it may not be directly instantiated, neither it may be extended.
31   * 
32   * @author <a href="mailto:bravegag@hotmail.com">Giovanni Azua</a>
33   * @version $Revision: 1.0 $ $Date: Nov 8, 2007 9:57:12 PM $
34   */
35  public final 
36  class AllHandleStrategy
37  implements IChainStrategy
38  {
39      //------------------------------------------------------------------------
40      // public
41      //------------------------------------------------------------------------
42      /**
43       * Returns Singleton instance of <code>AllHandleStrategy</code>.
44       * 
45       * @return Singleton instance of <code>AllHandleStrategy</code>.
46       */
47      public static IChainStrategy
48      getInstance()
49      {
50          return INSTANCE;
51      }
52  
53      //------------------------------------------------------------------------
54      /** 
55       * {@inheritDoc}
56       */
57      public void 
58      process(IHandler<Object> aHandler, Object aRequest)
59      {
60          if (aHandler.canHandle(aRequest))
61          {
62              aHandler.handle(aRequest);
63          }
64          
65          aHandler.getSuccessor().start(aRequest);            
66      }
67      
68      //------------------------------------------------------------------------
69      // private
70      //------------------------------------------------------------------------
71      private 
72      AllHandleStrategy()
73      {
74          // do nothing
75      }
76      
77      //------------------------------------------------------------------------
78      // members
79      //------------------------------------------------------------------------
80      private static final IChainStrategy INSTANCE = new AllHandleStrategy();
81  }