org.apache.bcel.generic

Class ConstantPoolGen

public class ConstantPoolGen extends Object implements Serializable

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 386056 2006-03-15 11:31:56Z tcurdt $

Author: M. Dahm

See Also: Constant

Nested Class Summary
static class	ConstantPoolGen.Index

Field Summary
Map	class_table
protected Constant[]	constants
Map	cp_table
static String	FIELDREF_DELIM
protected int	index
static String	IMETHODREF_DELIM
static String	METHODREF_DELIM
Map	n_a_t_table
static String	NAT_DELIM
protected int	size
Map	string_table
Map	utf8_table

Constructor Summary
	ConstantPoolGen(Constant[] cs) Initialize with given array of constants.
	ConstantPoolGen(ConstantPool cp) Initialize with given constant pool.
	ConstantPoolGen() Create empty constant pool.

Method Summary
int	addArrayClass(ArrayType type) Add a reference to an array class (e.g.
int	addClass(String str) Add a new Class reference to the ConstantPool, if it is not already in there.
int	addClass(ObjectType type) Add a new Class reference to the ConstantPool for a given type.
int	addClass_(String clazz)
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(String class_name, String field_name, 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(String class_name, String method_name, String signature) Add a new InterfaceMethodref constant to the ConstantPool, if it is not already in there.
int	addInterfaceMethodref(MethodGen method)
int	addLong(long n) Add a new long constant to the ConstantPool, if it is not already in there.
int	addMethodref(String class_name, String method_name, String signature) Add a new Methodref constant to the ConstantPool, if it is not already in there.
int	addMethodref(MethodGen method)
int	addNameAndType(String name, String signature) Add a new NameAndType constant to the ConstantPool if it is not already in there.
int	addString(String str) Add a new String constant to the ConstantPool, if it is not already in there.
int	addUtf8(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(String str) Look for ConstantClass in ConstantPool named `str'.
int	lookupDouble(double n) Look for ConstantDouble in ConstantPool.
int	lookupFieldref(String class_name, String field_name, 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(String class_name, String method_name, String signature) Look for ConstantInterfaceMethodref in ConstantPool.
int	lookupInterfaceMethodref(MethodGen method)
int	lookupLong(long n) Look for ConstantLong in ConstantPool.
int	lookupMethodref(String class_name, String method_name, String signature) Look for ConstantMethodref in ConstantPool.
int	lookupMethodref(MethodGen method)
int	lookupNameAndType(String name, String signature) Look for ConstantNameAndType in ConstantPool.
int	lookupString(String str) Look for ConstantString in ConstantPool containing String `str'.
int	lookupUtf8(String n) Look for ConstantUtf8 in ConstantPool.
void	setConstant(int i, Constant c) Use with care!
String	toString()

Field Detail

class_table

private Map class_table

constants

protected Constant[] constants

cp_table

private Map cp_table

FIELDREF_DELIM

private static final String FIELDREF_DELIM

index

protected int index

IMETHODREF_DELIM

private static final String IMETHODREF_DELIM

METHODREF_DELIM

private static final String METHODREF_DELIM

n_a_t_table

private Map n_a_t_table

NAT_DELIM

private static final String NAT_DELIM

size

protected int size

string_table

private Map string_table

utf8_table

private Map utf8_table

Constructor Detail

ConstantPoolGen

public ConstantPoolGen(Constant[] cs)

Initialize with given array of constants.

Parameters: cs 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

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

addClass

public int addClass(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: type Class to add

Returns: index of entry

addClass_

private int addClass_(String clazz)

addConstant

public int addConstant(Constant c, ConstantPoolGen cp)

Import constant from another ConstantPool and return new index.

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

addFieldref

public int addFieldref(String class_name, String field_name, String signature)

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

Parameters: class_name class name string to add field_name field name string to add signature signature string to add

Returns: index of entry

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

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

addInterfaceMethodref

public int addInterfaceMethodref(String class_name, String method_name, String signature)

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

Parameters: class_name class name string to add method_name method name string to add signature signature string to add

Returns: index of entry

addInterfaceMethodref

public int addInterfaceMethodref(MethodGen method)

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

addMethodref

public int addMethodref(String class_name, String method_name, String signature)

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

Parameters: class_name class name string to add method_name method name string to add signature method signature string to add

Returns: index of entry

addMethodref

public int addMethodref(MethodGen method)

addNameAndType

public int addNameAndType(String name, String signature)

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

Parameters: name Name string to add signature signature string to add

Returns: index of entry

addString

public int addString(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

addUtf8

public int addUtf8(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

adjustSize

protected void adjustSize()

Resize internal array of constants.

getConstant

public Constant getConstant(int i)

Parameters: i index in constant pool

Returns: constant pool entry at index i

getConstantPool

public ConstantPool getConstantPool()

Returns: intermediate constant pool

getFinalConstantPool

public ConstantPool getFinalConstantPool()

Returns: constant pool with proper length

getSize

public int getSize()

Returns: current size of constant pool

lookupClass

public int lookupClass(String str)

Look for ConstantClass in ConstantPool named `str'.

Parameters: str String to search for

Returns: index on success, -1 otherwise

lookupDouble

public int lookupDouble(double n)

Look for ConstantDouble in ConstantPool.

Parameters: n Double number to look for

Returns: index on success, -1 otherwise

lookupFieldref

public int lookupFieldref(String class_name, String field_name, 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

lookupFloat

public int lookupFloat(float n)

Look for ConstantFloat in ConstantPool.

Parameters: n Float number to look for

Returns: index on success, -1 otherwise

lookupInteger

public int lookupInteger(int n)

Look for ConstantInteger in ConstantPool.

Parameters: n integer number to look for

Returns: index on success, -1 otherwise

lookupInterfaceMethodref

public int lookupInterfaceMethodref(String class_name, String method_name, 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)

lookupLong

public int lookupLong(long n)

Look for ConstantLong in ConstantPool.

Parameters: n Long number to look for

Returns: index on success, -1 otherwise

lookupMethodref

public int lookupMethodref(String class_name, String method_name, 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)

lookupNameAndType

public int lookupNameAndType(String name, String signature)

Look for ConstantNameAndType in ConstantPool.

Parameters: name of variable/method signature of variable/method

Returns: index on success, -1 otherwise

lookupString

public int lookupString(String str)

Look for ConstantString in ConstantPool containing String `str'.

Parameters: str String to search for

Returns: index on success, -1 otherwise

lookupUtf8

public int lookupUtf8(String n)

Look for ConstantUtf8 in ConstantPool.

Parameters: n Utf8 string to look for

Returns: index on success, -1 otherwise

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

toString

public String toString()

Returns: String representation.