org.apache.bcel.generic

## Class ConstantPoolGen

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

-     public class ConstantPoolGen
      extends 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.
  See Also:
    `Constant`

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected Constant[]` | `constants` Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter
    `protected int` | `index` Deprecated. (since 6.0) will be made private; do not access directly, use getSize()
    `protected int` | `size` Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter

  - ### Constructor Summary

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

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `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(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(String className, 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(MethodGen method)`
    `int` | `addInterfaceMethodref(String className, String method_name, 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(String className, String method_name, String signature)` Add a new Methodref constant to the ConstantPool, if it is not already in there.
    `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 className, String fieldName, 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(String className, String method_name, String signature)` Look for ConstantInterfaceMethodref in ConstantPool.
    `int` | `lookupLong(long n)` Look for ConstantLong in ConstantPool.
    `int` | `lookupMethodref(MethodGen method)`
    `int` | `lookupMethodref(String className, String method_name, String signature)` Look for ConstantMethodref in ConstantPool.
    `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()`

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### 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()

  - ### Constructor Detail

    - #### ConstantPoolGen

          public ConstantPoolGen()

      Create empty constant pool.

    - #### 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.

  - ### 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(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(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

    - #### 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 className,
                                 String field_name,
                                 String signature)

      Add a new Fieldref constant to the ConstantPool, if it is not already in there.
      Parameters:
        `className` - 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(MethodGen method)

    - #### addInterfaceMethodref

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

      Add a new InterfaceMethodref constant to the ConstantPool, if it is not already in there.
      Parameters:
        `className` - class name string to add
        `method_name` - 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)

    - #### addMethodref

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

      Add a new Methodref constant to the ConstantPool, if it is not already in there.
      Parameters:
        `className` - class name string to add
        `method_name` - method name string to add
        `signature` - method signature string to add
      Returns:
        index of entry

    - #### 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 className,
                                    String fieldName,
                                    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)

    - #### lookupInterfaceMethodref

          public int lookupInterfaceMethodref(String className,
                                              String method_name,
                                              String signature)

      Look for ConstantInterfaceMethodref in ConstantPool.
      Parameters:
        `className` - Where to find method
        `method_name` - 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)

    - #### lookupMethodref

          public int lookupMethodref(String className,
                                     String method_name,
                                     String signature)

      Look for ConstantMethodref in ConstantPool.
      Parameters:
        `className` - Where to find method
        `method_name` - Guess what
        `signature` - return and argument types
      Returns:
        index on success, -1 otherwise

    - #### 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()

      Overrides:
        `toString` in class `Object`
      Returns:
        String representation.

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