1 //
2 // ========================================================================
3 // Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.annotations;
20
21 import java.util.ArrayList;
22 import java.util.List;
23
24 /**
25 * AnnotationIntrospector
26 *
27 *
28 */
29 public class AnnotationIntrospector
30 {
31 protected List<IntrospectableAnnotationHandler> _handlers = new ArrayList<IntrospectableAnnotationHandler>();
32
33
34 /**
35 * IntrospectableAnnotationHandler
36 *
37 * Interface for all handlers that wish to introspect a class to find a particular annotation
38 */
39 public interface IntrospectableAnnotationHandler
40 {
41 public void handle(Class<?> clazz);
42 }
43
44
45
46 /**
47 * AbstractIntrospectableAnnotationHandler
48 *
49 * Base class for handlers that introspect a class to find a particular annotation.
50 * A handler can optionally introspect the parent hierarchy of a class.
51 */
52 public static abstract class AbstractIntrospectableAnnotationHandler implements IntrospectableAnnotationHandler
53 {
54 private boolean _introspectAncestors;
55
56 public abstract void doHandle(Class<?> clazz);
57
58
59 public AbstractIntrospectableAnnotationHandler(boolean introspectAncestors)
60 {
61 _introspectAncestors = introspectAncestors;
62 }
63
64 public void handle(Class<?> clazz)
65 {
66 Class<?> c = clazz;
67
68 //process the whole inheritance hierarchy for the class
69 while (c!=null && (!c.equals(Object.class)))
70 {
71 doHandle(c);
72 if (!_introspectAncestors)
73 break;
74
75 c = c.getSuperclass();
76 }
77 }
78 }
79
80 public void registerHandler (IntrospectableAnnotationHandler handler)
81 {
82 _handlers.add(handler);
83 }
84
85 public void introspect (Class<?> clazz)
86 {
87 if (_handlers == null)
88 return;
89 if (clazz == null)
90 return;
91
92 for (IntrospectableAnnotationHandler handler:_handlers)
93 {
94 try
95 {
96 handler.handle(clazz);
97 }
98 catch (RuntimeException e)
99 {
100 throw e;
101 }
102 catch (Exception e)
103 {
104 throw new RuntimeException(e);
105 }
106 }
107
108 }
109 }