Class ConstantValue

java.lang.Object

org.apache.bcel.classfile.Attribute

org.apache.bcel.classfile.ConstantValue

All Implemented Interfaces:

Cloneable, Node

public final class ConstantValue
extends Attribute

This class is derived from Attribute and represents a constant value, that is, a default value for initializing a class field. This class is instantiated by the Attribute.readAttribute() method.

ConstantValue_attribute {
  u2 attribute_name_index;
  u4 attribute_length;
  u2 constantvalue_index;
}

See Also:

• Attribute

Field Summary

Fields inherited from class Attribute

constant_pool, EMPTY_ARRAY, length, name_index, tag

Modifier and Type	Field	Description
protected ConstantPool	constant_pool	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter.
static final Attribute[]	EMPTY_ARRAY	Empty array.
protected int	length	Deprecated. (since 6.0) (since 6.0) will be made private; do not access directly, use getter/setter.
protected int	name_index	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter.
protected byte	tag	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter.

Constructor Summary

Constructors

Constructor	Description
ConstantValue(int nameIndex, int length, int constantValueIndex, ConstantPool constantPool)	Constructs a ConstantValue.
ConstantValue(ConstantValue c)	Initialize from another object.

Method Summary

Modifier and Type	Method	Description
void	accept(Visitor v)	Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
Attribute	copy(ConstantPool constantPool)	Creates a deep copy of this attribute.
void	dump(DataOutputStream file)	Dumps constant value attribute to file stream on binary format.
int	getConstantValueIndex()	Gets the index in constant pool of constant value.
void	setConstantValueIndex(int constantValueIndex)	Sets the constant value index.
String	toString()

Methods inherited from class Attribute

addAttributeReader, addAttributeReader, clone, getConstantPool, getLength, getName, getNameIndex, getTag, println, readAttribute, readAttribute, readAttribute, removeAttributeReader, setConstantPool, setLength, setNameIndex

Modifier and Type	Method	Description
static void	addAttributeReader(String name, AttributeReader attributeReader)	Deprecated. (6.0) Use Attribute.addAttributeReader(String, UnknownAttributeReader) instead.
static void	addAttributeReader(String name, UnknownAttributeReader unknownAttributeReader)	Add an Attribute reader capable of parsing (user-defined) attributes named "name".
Object	clone()	Use copy() if you want to have a deep copy(), that is, with all references copied correctly.
final ConstantPool	getConstantPool()	Gets the constant pool used by this object.
final int	getLength()	Gets the length of attribute field in bytes.
String	getName()	Gets the name of the attribute.
final int	getNameIndex()	Gets the name index in constant pool of attribute name.
final byte	getTag()	Gets the tag of attribute, that is, its type.
protected static void	println(String msg)	Prints a message to stderr if debug mode is enabled.
static Attribute	readAttribute(DataInput dataInput, ConstantPool constantPool)	Reads one attribute using standard eight-byte Code headers.
static Attribute	readAttribute(DataInput dataInput, ConstantPool constantPool, boolean compactCodeHeader)	Reads one attribute using the selected Code header layout.
static Attribute	readAttribute(DataInputStream dataInputStream, ConstantPool constantPool)	Reads one attribute using standard eight-byte Code headers.
static void	removeAttributeReader(String name)	Remove attribute reader
final void	setConstantPool(ConstantPool constantPool)	Sets the constant pool to be used for this object.
final void	setLength(int length)	Sets the length in bytes.
final void	setNameIndex(int nameIndex)	Sets the name index of attribute.

Methods inherited from class Object

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

Constructor Details

ConstantValue

public ConstantValue(ConstantValue c)

Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a physical copy.

Parameters:

c - Source to copy.

ConstantValue

public ConstantValue(int nameIndex,
 int length,
 int constantValueIndex,
 ConstantPool constantPool)

Constructs a ConstantValue.

Parameters:

nameIndex - Name index in constant pool.

length - Content length in bytes.

constantValueIndex - Index in constant pool.

constantPool - Array of constants.

Method Details

accept

public void accept(Visitor v)

Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. That is, the hierarchy of methods, fields, attributes, and other elements forms a tree of objects.

Specified by:

accept in interface Node

Specified by:

accept in class Attribute

Parameters:

v - Visitor object.

copy

public Attribute copy(ConstantPool constantPool)

Creates a deep copy of this attribute.

Specified by:

copy in class Attribute

Parameters:

constantPool - The constant pool.

Returns:

deep copy of this attribute.

dump

public void dump(DataOutputStream file)
          throws IOException

Dumps constant value attribute to file stream on binary format.

Overrides:

dump in class Attribute

Parameters:

file - Output file stream.

Throws:

IOException - Thrown if an I/O error occurs.

getConstantValueIndex

public int getConstantValueIndex()

Gets the index in constant pool of constant value.

Returns:

Index in constant pool of constant value.

setConstantValueIndex

public void setConstantValueIndex(int constantValueIndex)

Sets the constant value index.

Parameters:

constantValueIndex - The index info the constant pool of this constant value.

toString

public String toString()

Overrides:

toString in class Attribute

Returns:

String representation of constant value.