ScanCommonVisitor


1   /**
2    * EasyBeans
3    * Copyright (C) 2006 Bull S.A.S.
4    * Contact: easybeans@objectweb.org
5    *
6    * This library is free software; you can redistribute it and/or
7    * modify it under the terms of the GNU Lesser General Public
8    * License as published by the Free Software Foundation; either
9    * version 2.1 of the License, or any later version.
10   *
11   * This library is distributed in the hope that it will be useful,
12   * but WITHOUT ANY WARRANTY; without even the implied warranty of
13   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   * Lesser General Public License for more details.
15   *
16   * You should have received a copy of the GNU Lesser General Public
17   * License along with this library; if not, write to the Free Software
18   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
19   * USA
20   *
21   * --------------------------------------------------------------------------
22   * $Id: ScanCommonVisitor.java 377 2006-04-21 08:22:46Z benoitf $
23   * --------------------------------------------------------------------------
24   */
25  
26  package org.objectweb.easybeans.deployment.annotations.analyzer;
27  
28  import java.util.HashMap  ;
29  import java.util.Map  ;
30  
31  import org.objectweb.asm.AnnotationVisitor;
32  import org.objectweb.asm.commons.EmptyVisitor;
33  import org.objectweb.easybeans.deployment.annotations.metadata.interfaces.ISharedMetadata;
34  
35  /**
36   * This classes analyses annotation (could be class, method, attribute, etc).
37   * It is extended by classes for a specific type Class, Method, Attribute.
38   * @param <T> the kind of metadata visited by this visitor.
39   * @author Florent Benoit
40   */
41  public abstract class ScanCommonVisitor<T extends ISharedMetadata> extends EmptyVisitor {
42  
43      /**
44       * Annotation visitor which do nothing.
45       */
46      private EmptyVisitor emptyVisitor = null;
47  
48      /**
49       * Map of annotation visitors used by this visitor.<br>
50       * The key is the annotation descriptor (asm)
51       */
52      private Map  <String  , AnnotationVisitor> annotationVisitors = null;
53  
54      /**
55       * Constructor
56       * Build map of visitors.
57       */
58      public ScanCommonVisitor() {
59          annotationVisitors = new HashMap  <String  , AnnotationVisitor>();
60      }
61  
62      /**
63       * Build visitors used by this one.
64       * @param annotationMetadata metadata used
65       */
66      protected void initVisitors(final T annotationMetadata) {
67          emptyVisitor = new EmptyVisitor();
68  
69          // add @EJB
70          annotationVisitors.put(JavaxEjbEJBVisitor.TYPE,
71                  new JavaxEjbEJBVisitor<T>(annotationMetadata));
72  
73          // add @Resource
74          annotationVisitors.put(JavaxAnnotationResourceVisitor.TYPE,
75                  new JavaxAnnotationResourceVisitor<T>(annotationMetadata));
76  
77  
78          // add @PersistenceContext
79          annotationVisitors.put(JavaxPersistencePersistenceContextVisitor.TYPE,
80                  new JavaxPersistencePersistenceContextVisitor<T>(annotationMetadata));
81  
82          // add @PersistenceUnit
83          annotationVisitors.put(JavaxPersistencePersistenceUnitVisitor.TYPE,
84                  new JavaxPersistencePersistenceUnitVisitor<T>(annotationMetadata));
85  
86      }
87  
88  
89      /**
90       * @return empty visitor
91       */
92      protected EmptyVisitor getEmptyVisitor() {
93          return emptyVisitor;
94      }
95  
96      /**
97       * Visits an annotation of the class.
98       * @param desc the class descriptor of the annotation class.
99       * @param visible <tt>true</tt> if the annotation is visible at runtime.
100      * @return a non null visitor to visit the annotation values.
101      */
102     @Override  
103     public AnnotationVisitor visitAnnotation(final String   desc, final boolean visible) {
104         AnnotationVisitor av = annotationVisitors.get(desc);
105         if (av != null) {
106             return av;
107         }
108         return emptyVisitor;
109     }
110 
111     /**
112      * @return the visitors used by this scanner.
113      */
114     protected Map  <String  , AnnotationVisitor> getAnnotationVisitors() {
115         return annotationVisitors;
116     }
117 
118 
119 }
120
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