KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > oracle > toplink > libraries > asm > attrs > AnnotationDefaultAttribute


1 /**
2  * ASM: a very small and fast Java bytecode manipulation framework
3  * Copyright (c) 2000,2002,2003 INRIA, France Telecom
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the copyright holders nor the names of its
15  * contributors may be used to endorse or promote products derived from
16  * this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28  * THE POSSIBILITY OF SUCH DAMAGE.
29  */
30
31 package oracle.toplink.libraries.asm.attrs;
32
33 import oracle.toplink.libraries.asm.Attribute;
34 import oracle.toplink.libraries.asm.ByteVector;
35 import oracle.toplink.libraries.asm.ClassReader;
36 import oracle.toplink.libraries.asm.ClassWriter;
37 import oracle.toplink.libraries.asm.Label;
38
39 /**
40  * The AnnotationDefault attribute is a variable length attribute in the
41  * attributes table of certain method_info structures, namely those representing
42  * elements of annotation types. The AnnotationDefault attribute records the
43  * default value for the element represented by the method_info structure. Each
44  * method_info structures representing an element of an annotation types may contain
45  * at most one AnnotationDefault attribute. The JVM must make this default value
46  * available so it can be applied by appropriate reflective APIs.
47  * <p>
48  * The AnnotationDefault attribute has the following format:
49  * <pre>
50  * AnnotationDefault_attribute {
51  * u2 attribute_name_index;
52  * u4 attribute_length;
53  * element_value default_value;
54  * }
55  * </pre>
56  * The items of the AnnotationDefault structure are as follows:
57  * <dl>
58  * <dt>attribute_name_index</dt>
59  * <dd>The value of the attribute_name_index item must be a valid index into the
60  * constant_pool table. The constant_pool entry at that index must be a
61  * CONSTANT_Utf8_info structure representing the string "AnnotationDefault".</dd>
62  * <dt>attribute_length</dt>
63  * <dd>The value of the attribute_length item indicates the length of the attribute,
64  * excluding the initial six bytes. The value of the attribute_length item is
65  * thus dependent on the default value.</dd>
66  * <dt>default_value</dt>
67  * <dd>The default_value item represents the default value of the annotation type
68  * {@link oracle.toplink.libraries.asm.attrs.AnnotationElementValue element} whose default
69  * value is represented by this AnnotationDefault attribute.</dd>
70  * </dl>
71  *
72  * @see <a HREF="http://www.jcp.org/en/jsr/detail?id=175">JSR 175 : A Metadata
73  * Facility for the Java Programming Language</a>
74  *
75  * @author Eugene Kuleshov
76  */
77
78 public class AnnotationDefaultAttribute extends Attribute {
79   /**
80    * Default value for annotation. Could be one of
81    * <code>Byte</code>, <code>Character</code>, <code>Double</code>,
82    * <code>Float</code>, <code>Integer</code>, <code>Long</code>, <code>Short</code>,
83    * <code>Boolean</code>, <code>String</code>,
84    * <code>Annotation.EnumConstValue</code>, <code>Type</code>,
85    * <code>Annotation</code> or <code>Object[]</code>.
86    */
87   public Object JavaDoc defaultValue;
88
89   public AnnotationDefaultAttribute () {
90     super("AnnotationDefault");
91   }
92
93   public AnnotationDefaultAttribute ( Object JavaDoc defaultValue) {
94     this();
95     this.defaultValue = defaultValue;
96   }
97
98   protected Attribute read (ClassReader cr, int off,
99                             int len, char[] buf, int codeOff, Label[] labels) {
100     return new AnnotationDefaultAttribute( Annotation.readValue(cr, new int[] {off}, buf));
101   }
102
103   protected ByteVector write (ClassWriter cw, byte[] code,
104                               int len, int maxStack, int maxLocals) {
105     return Annotation.writeValue( new ByteVector(), defaultValue, cw);
106   }
107
108   /**
109    * Returns value in the format described in JSR-175 for Java source code.
110    *
111    * @return value in the format described in JSR-175 for Java source code.
112    */
113
114   public String JavaDoc toString () {
115     return "default " + defaultValue;
116   }
117 }
118
Popular Tags