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1
4 package org.oddjob.monitor.control;
5
6 import java.beans.PropertyChangeListener  ;
7 import java.lang.reflect.InvocationTargetException ;
8 import java.lang.reflect.Method ;
9 import java.util.HashMap ;
10 import java.util.Map ;
11
12 import org.apache.log4j.Logger;
13
14
17 public class PropertyChangeHelper {
18
19 private static final Logger logger = Logger
20 .getLogger(PropertyChangeHelper.class);
21
22 static final Map helpers = new HashMap ();
23
24
25 private Method addPropListenerMethod;
26
27
28 private Method removePropListenerMethod;
29
30 private PropertyChangeHelper(Class bean) {
31 Class beanClass = bean.getClass();
32 Class [] argClasses = { PropertyChangeListener .class };
33 try {
34 addPropListenerMethod = beanClass.getMethod(
35 "addPropertyChangeListener", argClasses);
36
37 removePropListenerMethod = beanClass.getMethod(
38 "removePropertyChangeListener", argClasses);
39 } catch (SecurityException e) {
40 logger.debug(e);
41 } catch (NoSuchMethodException e) {
42 }
44
45 }
46
47 private static PropertyChangeHelper lookup(Class bean) {
48 synchronized (helpers) {
49 PropertyChangeHelper helper = (PropertyChangeHelper) helpers
50 .get(bean);
51 if (helper == null) {
52 helper = new PropertyChangeHelper(bean);
53 helpers.put(bean, helper);
54 }
55 return helper;
56 }
57 }
58
59 public static void addPropertyChangeListener(Object obj,
60 PropertyChangeListener l) {
61 PropertyChangeHelper helper = lookup(obj.getClass());
62 if (helper.addPropListenerMethod == null) {
63 return;
64 }
65 Object [] args = { obj };
66 try {
67 helper.addPropListenerMethod.invoke(obj, args);
68 } catch (IllegalArgumentException e) {
69 logger.debug(e);
70 } catch (IllegalAccessException e) {
71 logger.debug(e);
72 } catch (InvocationTargetException e) {
73 logger.debug(e);
74 }
75 }
76
77 public static void removePropertyChangeListener(Object obj,
78 PropertyChangeListener l) {
79 PropertyChangeHelper helper = lookup(obj.getClass());
80 if (helper.removePropListenerMethod == null) {
81 return;
82 }
83 Object [] args = { obj };
84 try {
85 helper.removePropListenerMethod.invoke(obj, args);
86 } catch (IllegalArgumentException e) {
87 logger.debug(e);
88 } catch (IllegalAccessException e) {
89 logger.debug(e);
90 } catch (InvocationTargetException e) {
91 logger.debug(e);
92 }
93 }
94 }
95 |
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