ConstantPoolEntry (Apache Ant API)
Date: 2016-04-09

org.apache.tools.ant.taskdefs.optional.depend.constantpool

## Class ConstantPoolEntry

- java.lang.Object
- - org.apache.tools.ant.taskdefs.optional.depend.constantpool.ConstantPoolEntry

- Direct Known Subclasses:
    ClassCPInfo, ConstantCPInfo, FieldRefCPInfo, InterfaceMethodRefCPInfo, MethodHandleCPInfo, MethodRefCPInfo, NameAndTypeCPInfo, Utf8CPInfo

      public abstract class ConstantPoolEntry
      extends java.lang.Object

  An entry in the constant pool. This class contains a representation of the constant pool entries. It is an abstract base class for all the different forms of constant pool entry.
  See Also:
    `ConstantPool`

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `CONSTANT_CLASS` Tag value for Class entries.
    `static int` | `CONSTANT_DOUBLE` Tag value for Double entries.
    `static int` | `CONSTANT_FIELDREF` Tag value for Field Reference entries.
    `static int` | `CONSTANT_FLOAT` Tag value for Float entries.
    `static int` | `CONSTANT_INTEGER` Tag value for Integer entries.
    `static int` | `CONSTANT_INTERFACEMETHODREF` Tag value for Interface Method Reference entries.
    `static int` | `CONSTANT_INVOKEDYNAMIC` Tag value for InvokeDynamic entries
    `static int` | `CONSTANT_LONG` Tag value for Long entries.
    `static int` | `CONSTANT_METHODHANDLE` Tag value for Method Handle entries
    `static int` | `CONSTANT_METHODREF` Tag value for Method Reference entries.
    `static int` | `CONSTANT_METHODTYPE` Tag value for Method Type entries
    `static int` | `CONSTANT_NAMEANDTYPE` Tag value for Name and Type entries.
    `static int` | `CONSTANT_STRING` Tag value for String entries.
    `static int` | `CONSTANT_UTF8` Tag value for UTF8 entries.

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `ConstantPoolEntry(int tagValue, int entries)` Initialise the constant pool entry.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `int` | `getNumEntries()` Get the number of Constant Pool Entry slots within the constant pool occupied by this entry.
    `int` | `getTag()` Get the Entry's type tag.
    `boolean` | `isResolved()` Indicates whether this entry has been resolved.
    `abstract void` | `read(java.io.DataInputStream cpStream)` read a constant pool entry from a class stream.
    `static ConstantPoolEntry` | `readEntry(java.io.DataInputStream cpStream)` Read a constant pool entry from a stream.
    `void` | `resolve(ConstantPool constantPool)` Resolve this constant pool entry with respect to its dependents in the constant pool.

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

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

- - ### Field Detail

    - #### CONSTANT_UTF8

          public static final int CONSTANT_UTF8

      Tag value for UTF8 entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_INTEGER

          public static final int CONSTANT_INTEGER

      Tag value for Integer entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_FLOAT

          public static final int CONSTANT_FLOAT

      Tag value for Float entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_LONG

          public static final int CONSTANT_LONG

      Tag value for Long entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_DOUBLE

          public static final int CONSTANT_DOUBLE

      Tag value for Double entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_CLASS

          public static final int CONSTANT_CLASS

      Tag value for Class entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_STRING

          public static final int CONSTANT_STRING

      Tag value for String entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_FIELDREF

          public static final int CONSTANT_FIELDREF

      Tag value for Field Reference entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_METHODREF

          public static final int CONSTANT_METHODREF

      Tag value for Method Reference entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_INTERFACEMETHODREF

          public static final int CONSTANT_INTERFACEMETHODREF

      Tag value for Interface Method Reference entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_NAMEANDTYPE

          public static final int CONSTANT_NAMEANDTYPE

      Tag value for Name and Type entries.
      See Also:
        Constant Field Values

    - #### CONSTANT_METHODHANDLE

          public static final int CONSTANT_METHODHANDLE

      Tag value for Method Handle entries
      See Also:
        Constant Field Values

    - #### CONSTANT_METHODTYPE

          public static final int CONSTANT_METHODTYPE

      Tag value for Method Type entries
      See Also:
        Constant Field Values

    - #### CONSTANT_INVOKEDYNAMIC

          public static final int CONSTANT_INVOKEDYNAMIC

      Tag value for InvokeDynamic entries
      See Also:
        Constant Field Values

  - ### Constructor Detail

    - #### ConstantPoolEntry

          public ConstantPoolEntry(int tagValue,
                           int entries)

      Initialise the constant pool entry.
      Parameters:
        `tagValue` - the tag value which identifies which type of constant pool entry this is.
        `entries` - the number of constant pool entry slots this entry occupies.

  - ### Method Detail

    - #### readEntry

          public static ConstantPoolEntry readEntry(java.io.DataInputStream cpStream)
                                             throws java.io.IOException

      Read a constant pool entry from a stream. This is a factory method which reads a constant pool entry form a stream and returns the appropriate subclass for the entry.
      Parameters:
        `cpStream` - the stream from which the constant pool entry is to be read.
      Returns:
        the appropriate ConstantPoolEntry subclass representing the constant pool entry from the stream.
      Throws:
        `java.io.IOException` - if the constant pool entry cannot be read from the stream

    - #### isResolved

          public boolean isResolved()

      Indicates whether this entry has been resolved. In general a constant pool entry can reference another constant pool entry by its index value. Resolution involves replacing this index value with the constant pool entry at that index.
      Returns:
        true if this entry has been resolved.

    - #### resolve

          public void resolve(ConstantPool constantPool)

      Resolve this constant pool entry with respect to its dependents in the constant pool.
      Parameters:
        `constantPool` - the constant pool of which this entry is a member and against which this entry is to be resolved.

    - #### read

          public abstract void read(java.io.DataInputStream cpStream)
                             throws java.io.IOException

      read a constant pool entry from a class stream.
      Parameters:
        `cpStream` - the DataInputStream which contains the constant pool entry to be read.
      Throws:
        `java.io.IOException` - if there is a problem reading the entry from the stream.

    - #### getTag

          public int getTag()

      Get the Entry's type tag.
      Returns:
        The Tag value of this entry

    - #### getNumEntries

          public final int getNumEntries()

      Get the number of Constant Pool Entry slots within the constant pool occupied by this entry.
      Returns:
        the number of slots used.