1 /*
2 * Copyright 2010 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.callbackparams.annotation.util;
18
19 import java.lang.annotation.Annotation;
20 import java.lang.reflect.Field;
21
22 /**
23 * @deprecated
24 * This class is currently used by some of the utilities in the package
25 * {@link org.callbackparams.sandbox} but they will be modified and this package
26 * will be removed within the 1.0-release of the framework.
27 * @author Henrik Kaipe
28 */
29 public class EnumConstantDescriptor {
30
31 private final Field coreEnumField;
32
33 public EnumConstantDescriptor(final Enum<?> enumConstant) {
34 for (Field f : enumConstant.getDeclaringClass().getFields()) {
35 if (f.isEnumConstant()) {
36 if (false == f.isAccessible()) {
37 try {
38 f.setAccessible(true);
39 } catch (final SecurityException x) {
40 /* Never mind */
41 }
42 }
43 try {
44 if (enumConstant == f.get(null)) {
45 this.coreEnumField = f;
46 return;
47 }
48 } catch (Exception x) {
49 throw new Error(x);
50 }
51 }
52 }
53
54 throw new AssertionError("Unable to determine field for enum-constant "
55 + enumConstant);
56 }
57
58 /**
59 * Same as an incocation of {@link #getAnnotation(java.lang.Class, boolean)}
60 * with force=false.
61 * @see #getAnnotation(java.lang.Class, boolean)
62 */
63 public <A extends Annotation> A getAnnotation(Class<A> a) {
64 return getAnnotation(a, false);
65 }
66
67 /**
68 * Tries to find an annotation of the specified type.
69 * Primarly the annotations for the enum-constant will be investigated. If
70 * the desired annotation cannot be found on the enum-constant then the
71 * annotation will be picked from the enum-class.
72 *
73 * @return the desired annotation or (in case force=false) null in case it
74 * cannot be found
75 * @throws AssertionError in case the desired annotation can not be found
76 * and force=true
77 */
78 public <A extends Annotation> A getAnnotation(
79 final Class<A> a, final boolean force) {
80 A annotation = coreEnumField.getAnnotation(a);
81 if (null != annotation) {
82 return annotation;
83 }
84 annotation = coreEnumField.getDeclaringClass().getAnnotation(a);
85 if (null != annotation) {
86 return annotation;
87 } else if (false == force) {
88 return null;
89 } else {
90 throw new AssertionError("Neither the enum-constant "
91 + coreEnumField.getName() + " nor its class "
92 + coreEnumField.getDeclaringClass() + " is annotated with "
93 + a);
94 }
95 }
96 }