Package 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:

  • Field Details

    • 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 Details

    • 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 Details

    • 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 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(String className, String fieldName, 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)

    • addInterfaceMethodref

      public int addInterfaceMethodref(String className, String methodName, 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)

    • addMethodref

      public int addMethodref(String className, String methodName, 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(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 methodName, 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)

    • lookupMethodref

      public int lookupMethodref(String className, String methodName, 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(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.