View Javadoc

1   /*
2   * The contents of this file are subject to the BT "ZEUS" Open Source 
3   * Licence (L77741), Version 1.0 (the "Licence"); you may not use this file 
4   * except in compliance with the Licence. You may obtain a copy of the Licence
5   * from $ZEUS_INSTALL/licence.html or alternatively from
6   * http://www.labs.bt.com/projects/agents/zeus/licence.htm
7   * 
8   * Except as stated in Clause 7 of the Licence, software distributed under the
9   * Licence is distributed WITHOUT WARRANTY OF ANY KIND, either express or 
10  * implied. See the Licence for the specific language governing rights and 
11  * limitations under the Licence.
12  * 
13  * The Original Code is within the package zeus.*.
14  * The Initial Developer of the Original Code is British Telecommunications
15  * public limited company, whose registered office is at 81 Newgate Street, 
16  * London, EC1A 7AJ, England. Portions created by British Telecommunications 
17  * public limited company are Copyright 1996-9. All Rights Reserved.
18  * 
19  * THIS NOTICE MUST BE INCLUDED ON ANY COPY OF THIS FILE
20  */
21  
22  
23  package zeus.rete.action;
24  import zeus.rete.*;
25  import zeus.concepts.fn.*; 
26  import zeus.concepts.*;
27  import zeus.util.*;
28  import java.util.*;
29  import java.io.*;
30  
31  /*** 
32      
33      @author Simon Thompson
34      @since 1.1
35      */
36  public class  CloseAction extends ReteAction{
37      
38      /***
39          execute an action that closes a stream
40          */
41      public void executeAction (Action a, Info info) { 
42                ValueFunction var = ((ValueFunction)a.head).resolve(info.getBindings());
43                if ( var == null || var.getID() != ValueFunction.ID ) {
44                   Core.USER_ERROR("Cannot resolve reader/writer '" + a.head + "' in action " + a);
45                   return;
46                }
47                String name = ((IdFn)var).getValue();
48  
49  	          PrintWriter out = (PrintWriter)conflictHandler.getWriters().remove(name);
50                if ( out != null ) {
51                   out.flush();
52                   out.close();
53                   return;
54                }
55  
56                DataReader in = (DataReader)conflictHandler.getReaders().remove(name);
57                if ( in != null ) {
58                   in = null;
59                   return; 
60                }
61  
62                Core.USER_ERROR("Unknown reader/writer '" + name + "' in " + a);
63      
64      }
65      
66      
67  }