Package org.apache.bcel.classfile

Class Constant

java.lang.Object

org.apache.bcel.classfile.Constant

All Implemented Interfaces:

java.lang.Cloneable, Node

Direct Known Subclasses:

ConstantClass, ConstantCP, ConstantDouble, ConstantFloat, ConstantInteger, ConstantLong, ConstantMethodHandle, ConstantMethodType, ConstantModule, ConstantNameAndType, ConstantPackage, ConstantString, ConstantUtf8

public abstract class Constant
extends java.lang.Object
implements java.lang.Cloneable, Node

Abstract superclass for classes to represent the different constant types in the constant pool of a class file. The classes keep closely to the JVM specification.

Field Summary

Fields

Modifier and Type	Field	Description
private static BCELComparator<Constant>	bcelComparator
(package private) static Constant[]	EMPTY_ARRAY
protected byte	tag	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter.

Constructor Summary

Constructors

Constructor	Description
Constant(byte tag)

Method Summary

Modifier and Type	Method	Description
abstract void	accept(Visitor v)	Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
java.lang.Object	clone()
Constant	copy()	Creates a deep copy of this constant.
abstract void	dump(java.io.DataOutputStream file)	Dumps constant to file stream in binary format.
boolean	equals(java.lang.Object obj)	Returns value as defined by given BCELComparator strategy.
static BCELComparator<Constant>	getComparator()	Gets the comparison strategy object.
byte	getTag()	Gets the tag of constant.
int	hashCode()	Returns value as defined by given BCELComparator strategy.
static Constant	readConstant(java.io.DataInput dataInput)	Reads one constant from the given input, the type depends on a tag byte.
static void	setComparator(BCELComparator<Constant> comparator)	Sets the comparison strategy object.
java.lang.String	toString()

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

EMPTY_ARRAY

static final Constant[] EMPTY_ARRAY

bcelComparator

private static BCELComparator<Constant> bcelComparator

tag

@Deprecated
protected byte tag

Deprecated.

(since 6.0) will be made private; do not access directly, use getter/setter.

Constructor Detail

Constant

Constant(byte tag)

Method Detail

getComparator

public static BCELComparator<Constant> getComparator()

Gets the comparison strategy object.

Returns:

Comparison strategy object.

readConstant

public static Constant readConstant(java.io.DataInput dataInput)
                             throws java.io.IOException,
                                    ClassFormatException

Reads one constant from the given input, the type depends on a tag byte.

Parameters:

dataInput - Input stream.

Returns:

Constant object.

Throws:

java.io.IOException - if an I/O error occurs reading from the given dataInput.

ClassFormatException - if the next byte is not recognized

Since:

6.0 made public

setComparator

public static void setComparator(BCELComparator<Constant> comparator)

Sets the comparison strategy object.

Parameters:

comparator - Comparison strategy object.

accept

public abstract void accept(Visitor v)

Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.

Specified by:

accept in interface Node

Parameters:

v - Visitor object.

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

copy

public Constant copy()

Creates a deep copy of this constant.

Returns:

deep copy of this constant.

dump

public abstract void dump(java.io.DataOutputStream file)
                   throws java.io.IOException

Dumps constant to file stream in binary format.

Parameters:

file - the output stream.

Throws:

java.io.IOException - if an I/O error occurs.

equals

public boolean equals(java.lang.Object obj)

Returns value as defined by given BCELComparator strategy. By default two Constant objects are said to be equal when the result of toString() is equal.

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(Object)

getTag

public final byte getTag()

Gets the tag of constant.

Returns:

Tag of constant, that is, its type. No setTag() method to avoid confusion.

hashCode

public int hashCode()

Returns value as defined by given BCELComparator strategy. By default return the hash code of the result of toString().

Overrides:

hashCode in class java.lang.Object

See Also:

Object.hashCode()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

String representation.