org.apache.bcel.classfile

Class Attribute

Implemented Interfaces:
Cloneable, Node, Serializable
Known Direct Subclasses:
Code, ConstantValue, Deprecated, ExceptionTable, InnerClasses, LineNumberTable, LocalVariableTable, PMGClass, Signature, SourceFile, StackMap, Synthetic, Unknown

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

Abstract super class for Attribute objects. Currently the ConstantValue, SourceFile, Code, Exceptiontable, LineNumberTable, LocalVariableTable, InnerClasses and Synthetic attributes are supported. The Unknown attribute stands for non-standard-attributes.
Version:
$Id: Attribute.java,v 1.8 2002/07/11 19:39:04 mdahm Exp $
Author:
M. Dahm
See Also:
ConstantValue, SourceFile, Code, Unknown, ExceptionTable, LineNumberTable, LocalVariableTable, InnerClasses, Synthetic, Deprecated, Signature

Field Summary

protected ConstantPool
constant_pool
protected int
length
protected int
name_index
protected byte
tag

Constructor Summary

Attribute(byte tag, int name_index, int length, ConstantPool constant_pool)

Method Summary

abstract void
accept(Visitor v)
Called by objects that are traversing the nodes of the tree implicitely defined by the contents of a Java class.
static void
addAttributeReader(String name, AttributeReader r)
Add an Attribute reader capable of parsing (user-defined) attributes named "name".
Object
clone()
Use copy() if you want to have a deep copy(), i.e., with all references copied correctly.
abstract Attribute
copy(ConstantPool constant_pool)
void
dump(DataOutputStream file)
Dump attribute to file stream in binary format.
ConstantPool
getConstantPool()
int
getLength()
int
getNameIndex()
byte
getTag()
static Attribute
readAttribute(DataInputStream file, ConstantPool constant_pool)
static void
removeAttributeReader(String name)
Remove attribute reader
void
setConstantPool(ConstantPool constant_pool)
void
setLength(int length)
void
setNameIndex(int name_index)
String
toString()

Field Details

constant_pool

protected ConstantPool constant_pool

length

protected int length

name_index

protected int name_index

tag

protected byte tag

Constructor Details

Attribute

protected Attribute(byte tag,
                    int name_index,
                    int length,
                    ConstantPool constant_pool)

Method Details

accept

public abstract void accept(Visitor v)
Called by objects that are traversing the nodes of the tree implicitely 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

addAttributeReader

public static void addAttributeReader(String name,
                                      AttributeReader r)
Add an Attribute reader capable of parsing (user-defined) attributes named "name". You should not add readers for the standard attributes such as "LineNumberTable", because those are handled internally.
Parameters:
name - the name of the attribute as stored in the class file
r - the reader object

clone

public Object clone()
Use copy() if you want to have a deep copy(), i.e., with all references copied correctly.
Returns:
shallow copy of this attribute

copy

public abstract Attribute copy(ConstantPool constant_pool)
Returns:
deep copy of this attribute

dump

public void dump(DataOutputStream file)
            throws IOException
Dump attribute to file stream in binary format.
Parameters:
file - Output file stream

getConstantPool

public final ConstantPool getConstantPool()
Returns:
Constant pool used by this object.
See Also:
ConstantPool

getLength

public final int getLength()
Returns:
Length of attribute field in bytes.

getNameIndex

public final int getNameIndex()
Returns:
Name index in constant pool of attribute name.

getTag

public final byte getTag()
Returns:
Tag of attribute, i.e., its type. Value may not be altered, thus there is no setTag() method.

readAttribute

public static final Attribute readAttribute(DataInputStream file,
                                            ConstantPool constant_pool)
            throws IOException,
                   ClassFormatException

removeAttributeReader

public static void removeAttributeReader(String name)
Remove attribute reader
Parameters:
name - the name of the attribute as stored in the class file

setConstantPool

public final void setConstantPool(ConstantPool constant_pool)
Parameters:
constant_pool - Constant pool to be used for this object.
See Also:
ConstantPool

setLength

public final void setLength(int length)
Parameters:

setNameIndex

public final void setNameIndex(int name_index)
Parameters:
name_index - of attribute.

toString

public String toString()
Returns:
attribute name.