oracle.toplink.libraries.asm.attrs

Class AnnotationDefaultAttribute

java.lang.Object

oracle.toplink.libraries.asm.Attribute

oracle.toplink.libraries.asm.attrs.AnnotationDefaultAttribute

Direct Known Subclasses:

ASMAnnotationDefaultAttribute

public class AnnotationDefaultAttribute
extends Attribute

The AnnotationDefault attribute is a variable length attribute in the attributes table of certain method_info structures, namely those representing elements of annotation types. The AnnotationDefault attribute records the default value for the element represented by the method_info structure. Each method_info structures representing an element of an annotation types may contain at most one AnnotationDefault attribute. The JVM must make this default value available so it can be applied by appropriate reflective APIs.

The AnnotationDefault attribute has the following format:

    AnnotationDefault_attribute {
      u2 attribute_name_index;
      u4 attribute_length;
      element_value default_value;
    }
 

The items of the AnnotationDefault structure are as follows:

attribute_name_index

The value of the attribute_name_index item must be a valid index into the constant_pool table. The constant_pool entry at that index must be a CONSTANT_Utf8_info structure representing the string "AnnotationDefault".

attribute_length

The value of the attribute_length item indicates the length of the attribute, excluding the initial six bytes. The value of the attribute_length item is thus dependent on the default value.

default_value

The default_value item represents the default value of the annotation type element whose default value is represented by this AnnotationDefault attribute.

Author:

Eugene Kuleshov

See Also:

JSR 175 : A Metadata Facility for the Java Programming Language

Field Summary

Fields

Modifier and Type	Field and Description
java.lang.Object	defaultValue Default value for annotation.

Fields inherited from class oracle.toplink.libraries.asm.Attribute

next, type

Constructor Summary

Constructors

Constructor and Description
AnnotationDefaultAttribute()
AnnotationDefaultAttribute(java.lang.Object defaultValue)

Method Summary

Modifier and Type	Method and Description
protected Attribute	read(ClassReader cr, int off, int len, char[] buf, int codeOff, Label[] labels) Reads a type attribute.
java.lang.String	toString() Returns value in the format described in JSR-175 for Java source code.
protected ByteVector	write(ClassWriter cw, byte[] code, int len, int maxStack, int maxLocals) Returns the byte array form of this attribute.

Methods inherited from class oracle.toplink.libraries.asm.Attribute

getLabels, isUnknown

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

defaultValue

public java.lang.Object defaultValue

Default value for annotation. Could be one of Byte, Character, Double, Float, Integer, Long, Short, Boolean, String, Annotation.EnumConstValue, Type, Annotation or Object[].

Constructor Detail

AnnotationDefaultAttribute

public AnnotationDefaultAttribute()

AnnotationDefaultAttribute

public AnnotationDefaultAttribute(java.lang.Object defaultValue)

Method Detail

read

protected Attribute read(ClassReader cr,
                         int off,
                         int len,
                         char[] buf,
                         int codeOff,
                         Label[] labels)

Description copied from class: Attribute

Reads a type attribute. This method must return a new Attribute object, of type type, corresponding to the len bytes starting at the given offset, in the given class reader.

Overrides:

read in class Attribute

Parameters:

cr - the class that contains the attribute to be read.

off - index of the first byte of the attribute's content in cr.b. The 6 attribute header bytes, containing the type and the length of the attribute, are not taken into account here.

len - the length of the attribute's content.

buf - buffer to be used to call readUTF8, readClass or readConst.

codeOff - index of the first byte of code's attribute content in cr.b, or -1 if the attribute to be read is not a code attribute. The 6 attribute header bytes, containing the type and the length of the attribute, are not taken into account here.

labels - the labels of the method's code, or null if the attribute to be read is not a code attribute.

Returns:

a new Attribute object corresponding to the given bytes.

write

protected ByteVector write(ClassWriter cw,
                           byte[] code,
                           int len,
                           int maxStack,
                           int maxLocals)

Description copied from class: Attribute

Returns the byte array form of this attribute.

Overrides:

write in class Attribute

Parameters:

cw - the class to which this attribute must be added. This parameter can be used to add to the constant pool of this class the items that corresponds to this attribute.

code - the bytecode of the method corresponding to this code attribute, or null if this attribute is not a code attributes.

len - the length of the bytecode of the method corresponding to this code attribute, or null if this attribute is not a code attribute.

maxStack - the maximum stack size of the method corresponding to this code attribute, or -1 if this attribute is not a code attribute.

maxLocals - the maximum number of local variables of the method corresponding to this code attribute, or -1 if this attribute is not a code attribute.

Returns:

the byte array form of this attribute.

toString

public java.lang.String toString()

Returns value in the format described in JSR-175 for Java source code.

Overrides:

toString in class java.lang.Object

Returns:

value in the format described in JSR-175 for Java source code.