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Java > Open Source Codes > com > teamkonzept > webman > mainint > events > CachedEventDistributor


1 package com.teamkonzept.webman.mainint.events;
2
3 import java.util.*;
4
5 import com.teamkonzept.web.*;
6 import com.teamkonzept.lib.*;
7 import org.apache.log4j.Category;
8
9 /**
10     Defaultimplementierung eines EventVerteilers, nur isHandler ist noch
11     abstrakt, cached die Events !, d.h. es gibt nur EINEN Handler pro Event
12 */
13 public abstract class CachedEventDistributor extends DefaultEventDistributor implements ErrorCodes
14 {
15     private Hashtable cache = new Hashtable();
16     
17     /** for logging */
18     static Category cat = Category.getInstance(CachedEventDistributor.class);
19     
20     
21     public void handleEvent(TKEvent evt) throws TKException
22     {
23         cat.debug("Got Event: " + evt);
24         TKEventHandler handler = (TKEventHandler)cache.get(evt.getName());
25         if (handler == null)
26         {
27             for (int i=0; i < handlerList.size();i++)
28             {
29                 handler = (TKEventHandler)handlerList.elementAt(i);
30                 if (handler.isHandler(evt))
31                 {
32                     cache.put(evt.getName(), handler);
33                     handler.handleEvent(evt);
34                     return;
35                 }
36             }
37             throw new TKException("Invalid Event !" + evt.getName(),INVALID_EVENT, NORMAL_SEVERITY, false, null);
38         }
39         handler.handleEvent(evt);
40     }
41     
42     /**
43         überladen, da der Cache geändert werden muss
44     */
45     public void removeEventHandler(TKEventHandler handler)
46     {
47         // aus Cache entfernen <-> value, nicht key muss entfernt werden !
48 Enumeration keys = cache.keys();
49         while (keys.hasMoreElements())
50         {
51             Object JavaDoc obj = keys.nextElement();
52             if (cache.get(obj) == handler)
53                 cache.remove(obj);
54         }
55         super.removeEventHandler(handler);
56     }
57     
58 }
59
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