bcel API: Class ConstantPoolGen

org.apache.bcel.generic
Class ConstantPoolGen

java.lang.Object
  |
  +--org.apache.bcel.generic.ConstantPoolGen

public class ConstantPoolGen

extends java.lang.Object

This class is used to build up a constant pool. The user adds constants via `addXXX' methods, `addString', `addClass', etc.. These methods return an index into the constant pool. Finally, `getFinalConstantPool()' returns the constant pool built up. Intermediate versions of the constant pool can be obtained with `getConstantPool()'. A constant pool has capacity for Constants.MAX_SHORT entries. Note that the first (0) is used by the JVM and that Double and Long constants need two slots.

Version:

$Id: ConstantPoolGen.java,v 1.1.1.1 2001/10/29 20:00:08 jvanzyl Exp $

Author:

M. Dahm

See Also:

Constant

Field Summary

protected Constant[]	constants
protected int	index
protected int	size

Constructor Summary

ConstantPoolGen()
Create empty constant pool.

ConstantPoolGen(Constant[] cs)
Initialize with given array of constants.

ConstantPoolGen(ConstantPool cp)
Initialize with given constant pool.

Method Summary

int	addArrayClass(ArrayType type) Add a reference to an array class (e.g.
int	addClass(ObjectType type) Add a new Class reference to the ConstantPool for a given type.
int	addClass(java.lang.String str) Add a new Class reference to the ConstantPool, if it is not already in there.
int	addConstant(Constant c, ConstantPoolGen cp) Import constant from another ConstantPool and return new index.
int	addDouble(double n) Add a new double constant to the ConstantPool, if it is not already in there.
int	addFieldref(java.lang.String class_name, java.lang.String field_name, java.lang.String signature) Add a new Fieldref constant to the ConstantPool, if it is not already in there.
int	addFloat(float n) Add a new Float constant to the ConstantPool, if it is not already in there.
int	addInteger(int n) Add a new Integer constant to the ConstantPool, if it is not already in there.
int	addInterfaceMethodref(MethodGen method)
int	addInterfaceMethodref(java.lang.String class_name, java.lang.String method_name, java.lang.String signature) Add a new InterfaceMethodref constant to the ConstantPool, if it is not already in there.
int	addLong(long n) Add a new long constant to the ConstantPool, if it is not already in there.
int	addMethodref(MethodGen method)
int	addMethodref(java.lang.String class_name, java.lang.String method_name, java.lang.String signature) Add a new Methodref constant to the ConstantPool, if it is not already in there.
int	addNameAndType(java.lang.String name, java.lang.String signature) Add a new NameAndType constant to the ConstantPool if it is not already in there.
int	addString(java.lang.String str) Add a new String constant to the ConstantPool, if it is not already in there.
int	addUtf8(java.lang.String n) Add a new Utf8 constant to the ConstantPool, if it is not already in there.
protected void	adjustSize() Resize internal array of constants.
Constant	getConstant(int i)
ConstantPool	getConstantPool()
ConstantPool	getFinalConstantPool()
int	getSize()
int	lookupClass(java.lang.String str) Look for ConstantClass in ConstantPool named `str'.
int	lookupDouble(double n) Look for ConstantDouble in ConstantPool.
int	lookupFieldref(java.lang.String class_name, java.lang.String field_name, java.lang.String signature) Look for ConstantFieldref in ConstantPool.
int	lookupFloat(float n) Look for ConstantFloat in ConstantPool.
int	lookupInteger(int n) Look for ConstantInteger in ConstantPool.
int	lookupInterfaceMethodref(MethodGen method)
int	lookupInterfaceMethodref(java.lang.String class_name, java.lang.String method_name, java.lang.String signature) Look for ConstantInterfaceMethodref in ConstantPool.
int	lookupLong(long n) Look for ConstantLong in ConstantPool.
int	lookupMethodref(MethodGen method)
int	lookupMethodref(java.lang.String class_name, java.lang.String method_name, java.lang.String signature) Look for ConstantMethodref in ConstantPool.
int	lookupNameAndType(java.lang.String name, java.lang.String signature) Look for ConstantNameAndType in ConstantPool.
int	lookupString(java.lang.String str) Look for ConstantString in ConstantPool containing String `str'.
int	lookupUtf8(java.lang.String n) Look for ConstantUtf8 in ConstantPool.
void	setConstant(int i, Constant c) Use with care!
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

size

protected int size

constants

protected Constant[] constants

index

protected int index

Constructor Detail

ConstantPoolGen

public ConstantPoolGen(Constant[] cs)

Initialize with given array of constants.

Parameters:

c - array of given constants, new ones will be appended

ConstantPoolGen

public ConstantPoolGen(ConstantPool cp)

Initialize with given constant pool.

ConstantPoolGen

public ConstantPoolGen()

Create empty constant pool.

Method Detail

adjustSize

protected void adjustSize()

Resize internal array of constants.

lookupString

public int lookupString(java.lang.String str)

Look for ConstantString in ConstantPool containing String `str'.

Parameters:

str - String to search for

Returns:

index on success, -1 otherwise

addString

public int addString(java.lang.String str)

Add a new String constant to the ConstantPool, if it is not already in there.

Parameters:

str - String to add

Returns:

index of entry

lookupClass

public int lookupClass(java.lang.String str)

Look for ConstantClass in ConstantPool named `str'.

Parameters:

str - String to search for

Returns:

index on success, -1 otherwise

addClass

public int addClass(java.lang.String str)

Add a new Class reference to the ConstantPool, if it is not already in there.

Parameters:

str - Class to add

Returns:

index of entry

addClass

public int addClass(ObjectType type)

Add a new Class reference to the ConstantPool for a given type.

Parameters:

str - Class to add

Returns:

index of entry

addArrayClass

public int addArrayClass(ArrayType type)

Add a reference to an array class (e.g. String[][]) as needed by MULTIANEWARRAY instruction, e.g. to the ConstantPool.

Parameters:

type - type of array class

Returns:

index of entry

lookupInteger

public int lookupInteger(int n)

Look for ConstantInteger in ConstantPool.

Parameters:

n - integer number to look for

Returns:

index on success, -1 otherwise

addInteger

public int addInteger(int n)

Add a new Integer constant to the ConstantPool, if it is not already in there.

Parameters:

n - integer number to add

Returns:

index of entry

lookupFloat

public int lookupFloat(float n)

Look for ConstantFloat in ConstantPool.

Parameters:

n - Float number to look for

Returns:

index on success, -1 otherwise

addFloat

public int addFloat(float n)

Add a new Float constant to the ConstantPool, if it is not already in there.

Parameters:

n - Float number to add

Returns:

index of entry

lookupUtf8

public int lookupUtf8(java.lang.String n)

Look for ConstantUtf8 in ConstantPool.

Parameters:

n - Utf8 string to look for

Returns:

index on success, -1 otherwise

addUtf8

public int addUtf8(java.lang.String n)

Add a new Utf8 constant to the ConstantPool, if it is not already in there.

Parameters:

n - Utf8 string to add

Returns:

index of entry

lookupLong

public int lookupLong(long n)

Look for ConstantLong in ConstantPool.

Parameters:

n - Long number to look for

Returns:

index on success, -1 otherwise

addLong

public int addLong(long n)

Add a new long constant to the ConstantPool, if it is not already in there.

Parameters:

n - Long number to add

Returns:

index of entry

lookupDouble

public int lookupDouble(double n)

Look for ConstantDouble in ConstantPool.

Parameters:

n - Double number to look for

Returns:

index on success, -1 otherwise

addDouble

public int addDouble(double n)

Add a new double constant to the ConstantPool, if it is not already in there.

Parameters:

n - Double number to add

Returns:

index of entry

lookupNameAndType

public int lookupNameAndType(java.lang.String name,
                             java.lang.String signature)

Look for ConstantNameAndType in ConstantPool.

Parameters:

name - of variable/method

signature - of variable/method

Returns:

index on success, -1 otherwise

addNameAndType

public int addNameAndType(java.lang.String name,
                          java.lang.String signature)

Add a new NameAndType constant to the ConstantPool if it is not already in there.

Parameters:

n - NameAndType string to add

Returns:

index of entry

lookupMethodref

public int lookupMethodref(java.lang.String class_name,
                           java.lang.String method_name,
                           java.lang.String signature)

Look for ConstantMethodref in ConstantPool.

Parameters:

class_name - Where to find method

method_name - Guess what

signature - return and argument types

Returns:

index on success, -1 otherwise

lookupMethodref

public int lookupMethodref(MethodGen method)

addMethodref

public int addMethodref(java.lang.String class_name,
                        java.lang.String method_name,
                        java.lang.String signature)

Add a new Methodref constant to the ConstantPool, if it is not already in there.

Parameters:

n - Methodref string to add

Returns:

index of entry

addMethodref

public int addMethodref(MethodGen method)

lookupInterfaceMethodref

public int lookupInterfaceMethodref(java.lang.String class_name,
                                    java.lang.String method_name,
                                    java.lang.String signature)

Look for ConstantInterfaceMethodref in ConstantPool.

Parameters:

class_name - Where to find method

method_name - Guess what

signature - return and argument types

Returns:

index on success, -1 otherwise

lookupInterfaceMethodref

public int lookupInterfaceMethodref(MethodGen method)

addInterfaceMethodref

public int addInterfaceMethodref(java.lang.String class_name,
                                 java.lang.String method_name,
                                 java.lang.String signature)

Add a new InterfaceMethodref constant to the ConstantPool, if it is not already in there.

Parameters:

n - InterfaceMethodref string to add

Returns:

index of entry

addInterfaceMethodref

public int addInterfaceMethodref(MethodGen method)

lookupFieldref

public int lookupFieldref(java.lang.String class_name,
                          java.lang.String field_name,
                          java.lang.String signature)

Look for ConstantFieldref in ConstantPool.

Parameters:

class_name - Where to find method

field_name - Guess what

signature - return and argument types

Returns:

index on success, -1 otherwise

addFieldref

public int addFieldref(java.lang.String class_name,
                       java.lang.String field_name,
                       java.lang.String signature)

Add a new Fieldref constant to the ConstantPool, if it is not already in there.

Parameters:

n - Fieldref string to add

Returns:

index of entry

getConstant

public Constant getConstant(int i)

Parameters:

i - index in constant pool

Returns:

constant pool entry at index i

setConstant

public void setConstant(int i,
                        Constant c)

Use with care!

Parameters:

i - index in constant pool

c - new constant pool entry at index i

getConstantPool

public ConstantPool getConstantPool()

Returns:

intermediate constant pool

getSize

public int getSize()

Returns:

current size of constant pool

getFinalConstantPool

public ConstantPool getFinalConstantPool()

Returns:

constant pool with proper length

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

String representation.

addConstant

public int addConstant(Constant c,
                       ConstantPoolGen cp)

Import constant from another ConstantPool and return new index.