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', and so on. 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.

See Also:

Constant

Field Summary

Fields
Modifier and Type	Field	Description
`private java.util.Map<java.lang.String,java.lang.Integer>`	`classTable`
`protected Constant[]`	`constants`	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter
`private java.util.Map<java.lang.String,java.lang.Integer>`	`cpTable`
`private static int`	`DEFAULT_BUFFER_SIZE`
`private static java.lang.String`	`FIELDREF_DELIM`
`private static java.lang.String`	`IMETHODREF_DELIM`
`protected int`	`index`	Deprecated. (since 6.0) will be made private; do not access directly, use getSize()
`private static java.lang.String`	`METHODREF_DELIM`
`private static java.lang.String`	`NAT_DELIM`
`private java.util.Map<java.lang.String,java.lang.Integer>`	`natTable`
`protected int`	`size`	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter
`private java.util.Map<java.lang.String,java.lang.Integer>`	`stringTable`
`private java.util.Map<java.lang.String,java.lang.Integer>`	`utf8Table`

Constructor Summary

Constructors
Constructor	Description
`ConstantPoolGen()`	Constructs a new empty constant pool.
`ConstantPoolGen(Constant[] cs)`	Constructs a new instance with the given array of constants.
`ConstantPoolGen(ConstantPool cp)`	Constructs a new instance with the given constant pool.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`addArrayClass(ArrayType type)`	Add a reference to an array class (for example, String[][]) as needed by MULTIANEWARRAY instruction, for example, to the ConstantPool.
`int`	`addClass(java.lang.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.
`private int`	`addClass_(java.lang.String clazz)`
`int`	`addConstant(Constant constant, ConstantPoolGen cpGen)`	Adds a constant from another ConstantPool and returns the 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 className, java.lang.String fieldName, 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(java.lang.String className, java.lang.String methodName, java.lang.String signature)`	Add a new InterfaceMethodref constant to the ConstantPool, if it is not already in there.
`int`	`addInterfaceMethodref(MethodGen method)`	Adds a new InterfaceMethodref constant to the ConstantPool.
`int`	`addLong(long n)`	Add a new long constant to the ConstantPool, if it is not already in there.
`int`	`addMethodref(java.lang.String className, java.lang.String methodName, java.lang.String signature)`	Add a new Methodref constant to the ConstantPool, if it is not already in there.
`int`	`addMethodref(MethodGen method)`	Adds a new Methodref constant to the ConstantPool.
`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.
`private int`	`computeIfAbsent(java.util.Map<java.lang.String,java.lang.Integer> map, java.lang.String key, int value)`
`Constant`	`getConstant(int i)`	Gets a constant pool entry at the specified index.
`ConstantPool`	`getConstantPool()`	Gets the intermediate constant pool.
`ConstantPool`	`getFinalConstantPool()`	Gets the constant pool with proper length.
`private int`	`getIndex(java.util.Map<java.lang.String,java.lang.Integer> map, java.lang.String key)`
`int`	`getSize()`	Gets the current size of constant pool.
`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 className, java.lang.String fieldName, 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(java.lang.String className, java.lang.String methodName, java.lang.String signature)`	Look for ConstantInterfaceMethodref in ConstantPool.
`int`	`lookupInterfaceMethodref(MethodGen method)`	Looks up an InterfaceMethodref in the ConstantPool.
`int`	`lookupLong(long n)`	Look for ConstantLong in ConstantPool.
`int`	`lookupMethodref(java.lang.String className, java.lang.String methodName, java.lang.String signature)`	Look for ConstantMethodref in ConstantPool.
`int`	`lookupMethodref(MethodGen method)`	Looks up a Methodref in the 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!
`private int`	`toIndex(java.lang.Integer index)`
`java.lang.String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - DEFAULT_BUFFER_SIZE
```
private static final int DEFAULT_BUFFER_SIZE
```
    See Also:
    
    Constant Field Values
  - METHODREF_DELIM
```
private static final java.lang.String METHODREF_DELIM
```
    See Also:
    
    Constant Field Values
  - IMETHODREF_DELIM
```
private static final java.lang.String IMETHODREF_DELIM
```
    See Also:
    
    Constant Field Values
  - FIELDREF_DELIM
```
private static final java.lang.String FIELDREF_DELIM
```
    See Also:
    
    Constant Field Values
  - NAT_DELIM
```
private static final java.lang.String NAT_DELIM
```
    See Also:
    
    Constant Field Values
  - size
```
@Deprecated
protected int size
```
    Deprecated.
    (since 6.0) will be made private; do not access directly, use getter/setter
  - constants
```
@Deprecated
protected Constant[] constants
```
    Deprecated.
    (since 6.0) will be made private; do not access directly, use getter/setter
  - index
```
@Deprecated
protected int index
```
    Deprecated.
    (since 6.0) will be made private; do not access directly, use getSize()
  - stringTable
```
private final java.util.Map<java.lang.String,java.lang.Integer> stringTable
```
  - classTable
```
private final java.util.Map<java.lang.String,java.lang.Integer> classTable
```
  - utf8Table
```
private final java.util.Map<java.lang.String,java.lang.Integer> utf8Table
```
  - natTable
```
private final java.util.Map<java.lang.String,java.lang.Integer> natTable
```
  - cpTable
```
private final java.util.Map<java.lang.String,java.lang.Integer> cpTable
```
- Constructor Detail
  - ConstantPoolGen
```
public ConstantPoolGen()
```
    Constructs a new empty constant pool.
  - ConstantPoolGen
```
public ConstantPoolGen(Constant[] cs)
```
    Constructs a new instance with the given array of constants.
    
    Parameters:
    
    cs - array of given constants, new ones will be appended.
  - ConstantPoolGen
```
public ConstantPoolGen(ConstantPool cp)
```
    Constructs a new instance with the given constant pool.
    
    Parameters:
    
    cp - the constant pool.
- Method Detail
  - addArrayClass
```
public int addArrayClass(ArrayType type)
```
    Add a reference to an array class (for example, String[][]) as needed by MULTIANEWARRAY instruction, for example, to the ConstantPool.
    
    Parameters:
    
    type - type of array class.
    
    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
```
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_
```
private int addClass_(java.lang.String clazz)
```
  - addConstant
```
public int addConstant(Constant constant,
                       ConstantPoolGen cpGen)
```
    Adds a constant from another ConstantPool and returns the new index.
    
    Parameters:
    
    constant - The constant to add.
    
    cpGen - Source pool.
    
    Returns:
    
    index of entry.
  - 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(java.lang.String className,
                       java.lang.String fieldName,
                       java.lang.String signature)
```
    Add a new Fieldref constant to the ConstantPool, if it is not already in there.
    
    Parameters:
    
    className - class name string to add.
    
    fieldName - 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(MethodGen method)
```
    Adds a new InterfaceMethodref constant to the ConstantPool.
    
    Parameters:
    
    method - the method to add.
    
    Returns:
    
    index of entry.
  - addInterfaceMethodref
```
public int addInterfaceMethodref(java.lang.String className,
                                 java.lang.String methodName,
                                 java.lang.String signature)
```
    Add a new InterfaceMethodref constant to the ConstantPool, if it is not already in there.
    
    Parameters:
    
    className - class name string to add.
    
    methodName - method name string to add.
    
    signature - signature string to add.
    
    Returns:
    
    index of entry.
  - 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(MethodGen method)
```
    Adds a new Methodref constant to the ConstantPool.
    
    Parameters:
    
    method - the method to add.
    
    Returns:
    
    index of entry.
  - addMethodref
```
public int addMethodref(java.lang.String className,
                        java.lang.String methodName,
                        java.lang.String signature)
```
    Add a new Methodref constant to the ConstantPool, if it is not already in there.
    
    Parameters:
    
    className - class name string to add.
    
    methodName - method name string to add.
    
    signature - method signature string to add.
    
    Returns:
    
    index of entry.
  - 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:
    
    name - Name string to add.
    
    signature - signature string to add.
    
    Returns:
    
    index of entry.
  - 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.
  - 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.
  - adjustSize
```
protected void adjustSize()
```
    Resize internal array of constants.
  - computeIfAbsent
```
private int computeIfAbsent(java.util.Map<java.lang.String,java.lang.Integer> map,
                            java.lang.String key,
                            int value)
```
  - getConstant
```
public Constant getConstant(int i)
```
    Gets a constant pool entry at the specified index.
    
    Parameters:
    
    i - index in constant pool.
    
    Returns:
    
    constant pool entry at index i.
  - getConstantPool
```
public ConstantPool getConstantPool()
```
    Gets the intermediate constant pool.
    
    Returns:
    
    intermediate constant pool.
  - getFinalConstantPool
```
public ConstantPool getFinalConstantPool()
```
    Gets the constant pool with proper length.
    
    Returns:
    
    constant pool with proper length.
  - getIndex
```
private int getIndex(java.util.Map<java.lang.String,java.lang.Integer> map,
                     java.lang.String key)
```
  - getSize
```
public int getSize()
```
    Gets the current size of constant pool.
    
    Returns:
    
    current size of constant pool.
  - 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.
  - 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(java.lang.String className,
                          java.lang.String fieldName,
                          java.lang.String signature)
```
    Look for ConstantFieldref in ConstantPool.
    
    Parameters:
    
    className - Where to find method.
    
    fieldName - 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(MethodGen method)
```
    Looks up an InterfaceMethodref in the ConstantPool.
    
    Parameters:
    
    method - the method to look for.
    
    Returns:
    
    index on success, -1 otherwise.
  - lookupInterfaceMethodref
```
public int lookupInterfaceMethodref(java.lang.String className,
                                    java.lang.String methodName,
                                    java.lang.String signature)
```
    Look for ConstantInterfaceMethodref in ConstantPool.
    
    Parameters:
    
    className - Where to find method.
    
    methodName - Guess what.
    
    signature - return and argument types.
    
    Returns:
    
    index on success, -1 otherwise.
  - 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(MethodGen method)
```
    Looks up a Methodref in the ConstantPool.
    
    Parameters:
    
    method - the method to look for.
    
    Returns:
    
    index on success, -1 otherwise.
  - lookupMethodref
```
public int lookupMethodref(java.lang.String className,
                           java.lang.String methodName,
                           java.lang.String signature)
```
    Look for ConstantMethodref in ConstantPool.
    
    Parameters:
    
    className - Where to find method.
    
    methodName - Guess what.
    
    signature - return and argument types.
    
    Returns:
    
    index on success, -1 otherwise.
  - 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.
  - 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.
  - 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.
  - 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.
  - toIndex
```
private int toIndex(java.lang.Integer index)
```
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    String representation.

Class ConstantPoolGen

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_BUFFER_SIZE

METHODREF_DELIM

IMETHODREF_DELIM

FIELDREF_DELIM

NAT_DELIM

size

constants

index

stringTable

classTable

utf8Table

natTable

cpTable

Constructor Detail

ConstantPoolGen

ConstantPoolGen

ConstantPoolGen

Method Detail

addArrayClass

addClass

addClass

addClass_

addConstant

addDouble

addFieldref

addFloat

addInteger

addInterfaceMethodref

addInterfaceMethodref

addLong

addMethodref

addMethodref

addNameAndType

addString

addUtf8

adjustSize

computeIfAbsent

getConstant

getConstantPool

getFinalConstantPool

getIndex

getSize

lookupClass

lookupDouble

lookupFieldref

lookupFloat

lookupInteger

lookupInterfaceMethodref

lookupInterfaceMethodref

lookupLong

lookupMethodref

lookupMethodref

lookupNameAndType

lookupString

lookupUtf8

setConstant

toIndex

toString