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Java > Open Source Codes > org > codehaus > aspectwerkz > reflect > impl > asm > AsmFieldInfo


1 /**************************************************************************************
2  * Copyright (c) Jonas BonŽr, Alexandre Vasseur. All rights reserved. *
3  * http://aspectwerkz.codehaus.org *
4  * ---------------------------------------------------------------------------------- *
5  * The software in this package is published under the terms of the LGPL license *
6  * a copy of which has been included with this distribution in the license.txt file. *
7  **************************************************************************************/
8 package org.codehaus.aspectwerkz.reflect.impl.asm;
9
10 import org.codehaus.aspectwerkz.reflect.ClassInfo;
11 import org.codehaus.aspectwerkz.reflect.FieldInfo;
12 import org.codehaus.aspectwerkz.transform.inlining.AsmHelper;
13 import org.codehaus.aspectwerkz.annotation.instrumentation.asm.AsmAnnotationHelper;
14 import org.codehaus.aspectwerkz.proxy.ProxyCompiler;
15
16 import org.objectweb.asm.Type;
17 import org.objectweb.asm.ClassReader;
18 import org.objectweb.asm.attrs.Attributes;
19
20 import java.util.List JavaDoc;
21 import java.util.ArrayList JavaDoc;
22 import java.io.IOException JavaDoc;
23 import java.io.InputStream JavaDoc;
24
25 /**
26  * ASM implementation of the FieldInfo interface.
27  *
28  * @author <a HREF="mailto:jboner@codehaus.org">Jonas BonŽr </a>
29  */
30 public class AsmFieldInfo extends AsmMemberInfo implements FieldInfo {
31
32     /**
33      * The field type name.
34      */
35     private String JavaDoc m_typeName;
36
37     /**
38      * The field type.
39      */
40     private ClassInfo m_type = null;
41
42     /**
43      * Creates a new field java instance.
44      *
45      * @param field
46      * @param declaringType
47      * @param loader
48      */
49     AsmFieldInfo(final FieldStruct field, final String JavaDoc declaringType, final ClassLoader JavaDoc loader) {
50         super(field, declaringType, loader);
51         m_typeName = Type.getType(field.desc).getClassName();
52     }
53
54     /**
55      * Returns the field info for the field specified.
56      *
57      * @param fieldName
58      * @param fieldDesc
59      * @param bytecode
60      * @param loader
61      * @return the field info
62      */
63     public static FieldInfo getFieldInfo(final String JavaDoc fieldName,
64                                          final String JavaDoc fieldDesc,
65                                          final byte[] bytecode,
66                                          final ClassLoader JavaDoc loader) {
67         String JavaDoc className = AsmClassInfo.retrieveClassNameFromBytecode(bytecode);
68         AsmClassInfoRepository repository = AsmClassInfoRepository.getRepository(loader);
69         ClassInfo classInfo = repository.getClassInfo(className);
70         if (classInfo == null) {
71             classInfo = AsmClassInfo.getClassInfo(bytecode, loader);
72         }
73         return classInfo.getField(AsmHelper.calculateFieldHash(fieldName, fieldDesc));
74     }
75
76     /**
77      * Returns the signature for the element.
78      *
79      * @return the signature for the element
80      */
81     public String JavaDoc getSignature() {
82         return AsmHelper.getFieldDescriptor(this);
83     }
84
85     /**
86      * Returns the type.
87      *
88      * @return the type
89      */
90     public ClassInfo getType() {
91         if (m_type == null) {
92             m_type = AsmClassInfo.getClassInfo(m_typeName, (ClassLoader JavaDoc) m_loaderRef.get());
93         }
94         return m_type;
95     }
96
97     /**
98      * Returns the annotations.
99      *
100      * @return the annotations
101      */
102     public List JavaDoc getAnnotations() {
103         if (m_annotations == null) {
104             try {
105                 InputStream JavaDoc in = null;
106                 ClassReader cr = null;
107                 try {
108                     if ((ClassLoader JavaDoc) m_loaderRef.get() != null) {
109                         in = ((ClassLoader JavaDoc) m_loaderRef.get()).getResourceAsStream(
110                                 m_declaringTypeName.replace('.', '/') + ".class"
111                         );
112                     } else {
113                         in = ClassLoader.getSystemClassLoader().getResourceAsStream(
114                                 m_declaringTypeName.replace('.', '/') + ".class"
115                         );
116                     }
117                     if (in == null) {
118                         in = ProxyCompiler.getProxyResourceAsStream((ClassLoader JavaDoc) m_loaderRef.get(), m_declaringTypeName);
119                     }
120                     cr = new ClassReader(in);
121                 } finally {
122                     try {
123                         in.close();
124                     } catch (Exception JavaDoc e) {
125                         ;
126                     }
127                 }
128                 List JavaDoc annotations = new ArrayList JavaDoc();
129                 cr.accept(
130                         new AsmAnnotationHelper.FieldAnnotationExtractor(
131                                 annotations, m_member.name, (ClassLoader JavaDoc) m_loaderRef.get()
132                         ),
133                         Attributes.getDefaultAttributes(),
134                         true
135                 );
136                 m_annotations = annotations;
137             } catch (IOException JavaDoc e) {
138                 // unlikely to occur since ClassInfo relies on getResourceAsStream
139 System.err.println(
140                         "WARN - could not load " + m_declaringTypeName + " as a resource to retrieve annotations"
141                 );
142                 m_annotations = AsmClassInfo.EMPTY_LIST;
143             }
144         }
145         return m_annotations;
146     }
147
148     public boolean equals(Object JavaDoc o) {
149         if (this == o) {
150             return true;
151         }
152         if (!(o instanceof FieldInfo)) {
153             return false;
154         }
155         FieldInfo fieldInfo = (FieldInfo) o;
156         if (!m_declaringTypeName.equals(fieldInfo.getDeclaringType().getName())) {
157             return false;
158         }
159         if (!m_member.name.equals(fieldInfo.getName())) {
160             return false;
161         }
162         if (!m_typeName.equals(fieldInfo.getType().getName())) {
163             return false;
164         }
165         return true;
166     }
167
168     public int hashCode() {
169         int result = 29;
170         result = (29 * result) + m_declaringTypeName.hashCode();
171         result = (29 * result) + m_member.name.hashCode();
172         result = (29 * result) + m_typeName.hashCode();
173         return result;
174     }
175
176     public String JavaDoc toString() {
177         StringBuffer JavaDoc sb = new StringBuffer JavaDoc(m_declaringTypeName);
178         sb.append('.').append(m_member.name).append(' ');
179         sb.append(m_member.desc);
180         return sb.toString();
181     }
182 }
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