Package org.apache.bcel.classfile

Class Unknown

java.lang.Object

org.apache.bcel.classfile.Attribute

org.apache.bcel.classfile.Unknown

All Implemented Interfaces:

java.lang.Cloneable, Node

public final class Unknown
extends Attribute

This class represents a reference to an unknown (that is, application-specific) attribute of a class. It is instantiated from the Attribute.readAttribute(java.io.DataInput, ConstantPool) method. Applications that need to read in application-specific attributes should create an UnknownAttributeReader implementation and attach it via Attribute.addAttributeReader(String, UnknownAttributeReader).

See Also:

Attribute, UnknownAttributeReader

Field Summary

Fields

Modifier and Type	Field	Description
private byte[]	bytes
(package private) static int	MAX_LEN	Arbitrary to limit the maximum length of unknown attributes to avoid OOM errors.
private static java.lang.String	MAX_LEN_PROP
private java.lang.String	name

Fields inherited from class org.apache.bcel.classfile.Attribute

constant_pool, EMPTY_ARRAY, length, name_index, tag

Constructor Summary

Constructors

Constructor	Description
Unknown(int nameIndex, int length, byte[] bytes, ConstantPool constantPool)	Constructs a new instance for a non-standard attribute.
Unknown(int nameIndex, int length, java.io.DataInput input, ConstantPool constantPool)	Constructs a new instance from a DataInput.
Unknown(Unknown unknown)	Constructs a new instance from another instance.

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(java.io.DataOutputStream file)	Dumps unknown bytes to file stream.
byte[]	getBytes()
java.lang.String	getName()	Gets the name of attribute.
void	setBytes(byte[] bytes)
java.lang.String	toString()

Methods inherited from class org.apache.bcel.classfile.Attribute

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

Methods inherited from class java.lang.Object

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

Field Detail

MAX_LEN

static final int MAX_LEN

Arbitrary to limit the maximum length of unknown attributes to avoid OOM errors.

See Also:

Constant Field Values

MAX_LEN_PROP

private static final java.lang.String MAX_LEN_PROP

See Also:

Constant Field Values

bytes

private byte[] bytes

name

private final java.lang.String name

Constructor Detail

Unknown

public Unknown(int nameIndex,
               int length,
               byte[] bytes,
               ConstantPool constantPool)

Constructs a new instance for a non-standard attribute.

Parameters:

nameIndex - Index in constant pool.

length - Content length in bytes.

bytes - Attribute contents.

constantPool - Array of constants.

Unknown

Unknown(int nameIndex,
        int length,
        java.io.DataInput input,
        ConstantPool constantPool)
 throws java.io.IOException

Constructs a new instance from a DataInput.

The size of an Attribute unknown to the JVM specification is limited to 1 MB and is overridden with the system property BCEL.Attribute.Unknown.max_attribute_length.

Parameters:

nameIndex - Index in constant pool.

length - Content length in bytes.

input - Input stream.

constantPool - Array of constants.

Throws:

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

See Also:

Attribute

Unknown

public Unknown(Unknown unknown)

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

Parameters:

unknown - Source.

Method Detail

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. I.e., the hierarchy of methods, fields, attributes, etc. spawns 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)

Description copied from class: Attribute

Creates a deep copy of this attribute.

Specified by:

copy in class Attribute

Parameters:

constantPool - constant pool to save.

Returns:

deep copy of this attribute.

dump

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

Dumps unknown bytes to file stream.

Overrides:

dump in class Attribute

Parameters:

file - Output file stream.

Throws:

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

getBytes

public byte[] getBytes()

Returns:

data bytes.

getName

public java.lang.String getName()

Description copied from class: Attribute

Gets the name of attribute.

Overrides:

getName in class Attribute

Returns:

name of attribute.

setBytes

public void setBytes(byte[] bytes)

Parameters:

bytes - the bytes to set.

toString

public java.lang.String toString()

Overrides:

toString in class Attribute

Returns:

String representation.