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1   /*
2    * Copyright (c) 2010 Carman Consulting, Inc.
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.metastopheles.annotation;
18  
19  import org.metastopheles.MetaDataDecorator;
20  import org.metastopheles.MetaDataObject;
21  
22  import java.lang.annotation.Annotation;
23  
24  /**
25   * An annotation-based metadata decorator.  Subclasses merely need to override the #{decorate} method.
26   * @since 1.0
27   * @author James Carman
28   */
29  public abstract class AnnotationBasedMetaDataDecorator<T extends MetaDataObject, A extends Annotation> implements MetaDataDecorator<T>
30  {
31  //**********************************************************************************************************************
32  // Fields
33  //**********************************************************************************************************************
34  
35      private final Class<A> annotationType;
36  
37  //**********************************************************************************************************************
38  // Constructors
39  //**********************************************************************************************************************
40  
41      public AnnotationBasedMetaDataDecorator(Class<A> annotationType)
42      {
43          this.annotationType = annotationType;
44      }
45  
46  //**********************************************************************************************************************
47  // Abstract Methods
48  //**********************************************************************************************************************
49  
50      protected abstract void decorate(T metaData, Annotation annotation);
51  
52  //**********************************************************************************************************************
53  // MetaDataDecorator Implementation
54  //**********************************************************************************************************************
55  
56      public void decorate(T metaData)
57      {
58          A annotation = metaData.getAnnotation(annotationType);
59          if (annotation != null)
60          {
61              decorate(metaData, annotation);
62          }
63      }
64  }