com.vladium.jcd.cls.attribute

Class Attribute_info

java.lang.Object

com.vladium.jcd.cls.attribute.Attribute_info

All Implemented Interfaces:

IClassFormatOutput, java.lang.Cloneable

Direct Known Subclasses:

BridgeAttribute_info, CodeAttribute_info, ConstantValueAttribute_info, ExceptionsAttribute_info, GenericAttribute_info, InnerClassesAttribute_info, LineNumberTableAttribute_info, SourceFileAttribute_info, SyntheticAttribute_info

public abstract class Attribute_info
extends java.lang.Object
implements java.lang.Cloneable, IClassFormatOutput

Abstract base for all XXXAttribute_info structures. It also works in conjunction with GenericAttribute_info class to process all unrecognized attributes.

Attributes are used in the ClassDef, Field_info, Method_info, and CodeAttribute_info structures of the .class file format. All attributes have the following general format:

  attribute_info {
          u2 attribute_name_index;
          u4 attribute_length;
          u1 info[attribute_length];
  }
 

For all attributes, the attribute_name_index must be a valid unsigned 16-bit index into the constant pool of the class. The constant pool entry at attribute_name_index must be a CONSTANT_Utf8_info string representing the name of the attribute. The value of the attribute_length item indicates the length of the subsequent information in bytes. The length does not include the initial six bytes that contain the attribute_name_index and attribute_length items.

Author:

(C) 2001, Vlad Roubtsov

See Also:

GenericAttribute_info

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	ATTRIBUTE_BRIDGE
static java.lang.String	ATTRIBUTE_CODE
static java.lang.String	ATTRIBUTE_CONSTANT_VALUE
static java.lang.String	ATTRIBUTE_EXCEPTIONS
static java.lang.String	ATTRIBUTE_INNERCLASSES
static java.lang.String	ATTRIBUTE_LINE_NUMBER_TABLE
static java.lang.String	ATTRIBUTE_SOURCEFILE
static java.lang.String	ATTRIBUTE_SYNTHETIC
protected long	m_attribute_length
int	m_name_index Constant pool index for CONSTANT_Utf8_info string representing the name of this attribute [always positive].

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Attribute_info(int attribute_name_index, long attribute_length)

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	accept(IAttributeVisitor visitor, java.lang.Object ctx)
java.lang.Object	clone() Chains to super.clone() and removes CloneNotSupportedException from the method signature.
java.lang.String	getName(ClassDef cls) Returns the name for this attribute within the constant pool context of 'cls' class definition.
abstract long	length() Returns the total length of this attribute when converted to .class format [including the 6-byte header]
static Attribute_info	new_Attribute_info(IConstantCollection constants, UDataInputStream bytes) Parses out a single Attribute_info element out of .class data in 'bytes'.
abstract java.lang.String	toString()
void	writeInClassFormat(UDataOutputStream out)

Methods inherited from class java.lang.Object

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

Field Detail

ATTRIBUTE_CODE

public static final java.lang.String ATTRIBUTE_CODE

See Also:

Constant Field Values

ATTRIBUTE_CONSTANT_VALUE

public static final java.lang.String ATTRIBUTE_CONSTANT_VALUE

See Also:

Constant Field Values

ATTRIBUTE_LINE_NUMBER_TABLE

public static final java.lang.String ATTRIBUTE_LINE_NUMBER_TABLE

See Also:

Constant Field Values

ATTRIBUTE_EXCEPTIONS

public static final java.lang.String ATTRIBUTE_EXCEPTIONS

See Also:

Constant Field Values

ATTRIBUTE_SYNTHETIC

public static final java.lang.String ATTRIBUTE_SYNTHETIC

See Also:

Constant Field Values

ATTRIBUTE_BRIDGE

public static final java.lang.String ATTRIBUTE_BRIDGE

See Also:

Constant Field Values

ATTRIBUTE_SOURCEFILE

public static final java.lang.String ATTRIBUTE_SOURCEFILE

See Also:

Constant Field Values

ATTRIBUTE_INNERCLASSES

public static final java.lang.String ATTRIBUTE_INNERCLASSES

See Also:

Constant Field Values

m_name_index

public int m_name_index

Constant pool index for CONSTANT_Utf8_info string representing the name of this attribute [always positive].

m_attribute_length

protected long m_attribute_length

Constructor Detail

Attribute_info

protected Attribute_info(int attribute_name_index,
              long attribute_length)

Method Detail

getName

public java.lang.String getName(ClassDef cls)

Returns the name for this attribute within the constant pool context of 'cls' class definition.

Parameters:

cls - class that contains this attribute

Returns:

attribute name

length

public abstract long length()

Returns the total length of this attribute when converted to .class format [including the 6-byte header]

accept

public abstract void accept(IAttributeVisitor visitor,
          java.lang.Object ctx)

toString

public abstract java.lang.String toString()

Overrides:

toString in class java.lang.Object

new_Attribute_info

public static Attribute_info new_Attribute_info(IConstantCollection constants,
                                UDataInputStream bytes)
                                         throws java.io.IOException

Parses out a single Attribute_info element out of .class data in 'bytes'.

Parameters:

constants - constant pool for the parent class [may not be null; not validated]

bytes - input .class data stream [may not be null; not validated]

Returns:

a single parsed attribute

Throws:

java.io.IOException - on input errors

clone

public java.lang.Object clone()

Chains to super.clone() and removes CloneNotSupportedException from the method signature.

Overrides:

clone in class java.lang.Object

writeInClassFormat

public void writeInClassFormat(UDataOutputStream out)
                        throws java.io.IOException

Specified by:

writeInClassFormat in interface IClassFormatOutput

Throws:

java.io.IOException