org.multijava.util.classfile
Class AttributeList

java.lang.Object
  org.multijava.util.classfile.AttributeList

public class AttributeList

extends java.lang.Object

This class represents a list of attributes within a ClassInfo structure (see JVM2, 4.7). This class also includes static helper methods for parsing attributes from .class files. This parsing is done using the chain-of-responsibility pattern. See the Attribute class for a sample member of the chain.

Nested Class Summary
static class	AttributeList.ParserIterator           This nested class implements a specialized iterator that returns successive parsers from the chain-of-responsibility and keeps clients from having to perform casts.

 

Field Summary
private  Attribute[]	attributes
private static java.util.LinkedList	attrParsers
static Attribute[]	EMPTY

 

Constructor Summary
	AttributeList()           Constructs an empty attribute list
(package private)	AttributeList(java.io.DataInput in, ConstantPool cp, boolean noCode)           Constructs an attribute list from a class file stream
(package private)	AttributeList(java.io.DataInput in, ConstantPool cp, Instruction[] insns)           Constructs an sub-attribute list of CodeInfo from a class file stream
	AttributeList(Attribute att1)           Constructs a one element attribute list
	AttributeList(Attribute att1, Attribute att2)           Constructs a two elements attribute list
	AttributeList(Attribute att1, Attribute att2, Attribute att3)           Constructs a three elements attribute list
	AttributeList(Attribute att1, Attribute att2, Attribute att3, Attribute att4)           Constructs a four elements attribute list

 

Method Summary
void	add(Attribute attr)           Adds an attribute to the list of attributes
static void	addParser(AttributeParser prsr)           Adds the given AttributeParser to the head of the chain-of-responsibility.
Attribute	get(int tag)           Return the first attribute for this tag
(package private)  int	getSize()           Returns the space in bytes used by this attribute in the classfile
boolean	isEmpty()
static AttributeList.ParserIterator	parserIterator()           Returns a specialized iterator that returns successive parsers from the chain-of-responsibility.
(package private) static Attribute	read(java.io.DataInput in, ConstantPool cp)           This method calls each member of the attribute parsing chain-of-responsibility in order to read the next attribute in the given input stream.
(package private) static Attribute	readCodeInfoAttribute(java.io.DataInput in, ConstantPool cp, Instruction[] insns)           This method calls each member of the attribute parsing chain-of-responsibility, in order, to read the next CodeInfo attribute in the given input stream.
(package private) static Attribute	readInterfaceOnly(java.io.DataInput in, ConstantPool cp)           This method calls each member of the attribute parsing chain-of-responsibility in order to read the next attribute in the given input stream.
(package private)  boolean	remove(int tag)           Removes an attribute from the list of attributes
static void	removeAllParsers()           Removes all parsers, including the default tail element BaseAttributeParser, from the chain-of-responsibility.
static void	removeParser(AttributeParser prsr)           Removes the given parser from the chain-of-responsibility.
static void	resetParsers()           Resets the chain-of-responsibility to just include the default tail element BaseAttributeParser.
(package private)  void	resolveConstants(ConstantPool cp)           Insert or check location of constant values in constant pool
(package private)  void	write(ConstantPool cp, java.io.DataOutput out)           Write this class into the the file (out) getting data position from the constant pool

 

Methods inherited from class java.lang.Object

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

 

Field Detail

attributes

private Attribute[] attributes

attrParsers

private static final java.util.LinkedList attrParsers

EMPTY

public static final Attribute[] EMPTY

AttributeList

public AttributeList()

Constructs an empty attribute list

AttributeList

public AttributeList(Attribute att1)

Constructs a one element attribute list

AttributeList

public AttributeList(Attribute att1,
                     Attribute att2)

Constructs a two elements attribute list

AttributeList

public AttributeList(Attribute att1,
                     Attribute att2,
                     Attribute att3)

Constructs a three elements attribute list

AttributeList

public AttributeList(Attribute att1,
                     Attribute att2,
                     Attribute att3,
                     Attribute att4)

Constructs a four elements attribute list

AttributeList

AttributeList(java.io.DataInput in,
              ConstantPool cp,
              boolean noCode)
        throws java.io.IOException,
               ClassFileFormatException

Constructs an attribute list from a class file stream

Parameters:

in - the stream to read from

cp - the constant pool

noCode - do not read code attribute

Throws:

java.io.IOException - an io problem has occured

ClassFileFormatException - attempt to write a bad classfile info

AttributeList

AttributeList(java.io.DataInput in,
              ConstantPool cp,
              Instruction[] insns)
        throws java.io.IOException,
               ClassFileFormatException

Constructs an sub-attribute list of CodeInfo from a class file stream

Parameters:

in - the stream to read from

cp - the constant pool

insns - (sparse) array of instructions

Throws:

java.io.IOException - an io problem has occured

ClassFileFormatException - attempt to write a bad classfile info

read

static Attribute read(java.io.DataInput in,
                      ConstantPool cp)
               throws java.io.IOException,
                      ClassFileFormatException

This method calls each member of the attribute parsing chain-of-responsibility in order to read the next attribute in the given input stream. Once a member of the chain matches no additional members are called. If no member matches then returns a GenericAttribute.

Throws:

java.io.IOException

ClassFileFormatException

readInterfaceOnly

static Attribute readInterfaceOnly(java.io.DataInput in,
                                   ConstantPool cp)
                            throws java.io.IOException,
                                   ClassFileFormatException

This method calls each member of the attribute parsing chain-of-responsibility in order to read the next attribute in the given input stream. Once a member of the chain matches no additional members are called. If no member matches then returns a GenericAttribute.

Throws:

java.io.IOException

ClassFileFormatException

readCodeInfoAttribute

static Attribute readCodeInfoAttribute(java.io.DataInput in,
                                       ConstantPool cp,
                                       Instruction[] insns)
                                throws java.io.IOException,
                                       ClassFileFormatException

This method calls each member of the attribute parsing chain-of-responsibility, in order, to read the next CodeInfo attribute in the given input stream. Once a member of the chain matches no additional members are called. If no member matches then returns a GenericAttribute.

Throws:

java.io.IOException

ClassFileFormatException

addParser

public static void addParser(AttributeParser prsr)

Adds the given AttributeParser to the head of the chain-of-responsibility.

removeParser

public static void removeParser(AttributeParser prsr)

Removes the given parser from the chain-of-responsibility.

removeAllParsers

public static void removeAllParsers()

Removes all parsers, including the default tail element BaseAttributeParser, from the chain-of-responsibility.

resetParsers

public static void resetParsers()

Resets the chain-of-responsibility to just include the default tail element BaseAttributeParser.

parserIterator

public static AttributeList.ParserIterator parserIterator()

Returns a specialized iterator that returns successive parsers from the chain-of-responsibility.

isEmpty

public boolean isEmpty()

get

public final Attribute get(int tag)

Return the first attribute for this tag

Parameters:

tag - the tag that identifies the attribute

add

public final void add(Attribute attr)

Adds an attribute to the list of attributes

Parameters:

attr - the attribute to add to the list, for convenience the argument may be null in which case this does nothing

remove

final boolean remove(int tag)

Removes an attribute from the list of attributes

Parameters:

tag - the tag that identifies the attribute

Returns:

true iff an attribute with given tag was in the list

getSize

int getSize()

Returns the space in bytes used by this attribute in the classfile

resolveConstants

void resolveConstants(ConstantPool cp)
                throws ClassFileFormatException

Insert or check location of constant values in constant pool

Parameters:

cp - the constant pool for this class

Throws:

ClassFileFormatException

write

void write(ConstantPool cp,
           java.io.DataOutput out)
     throws java.io.IOException,
            ClassFileFormatException

Write this class into the the file (out) getting data position from the constant pool

Parameters:

cp - the constant pool that contain all data

out - the file where to write this object info

Throws:

java.io.IOException - an io problem has occured

ClassFileFormatException - attempt to write a bad classfile info