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, 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
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_LONG
          Tag value for Long entries.
static int CONSTANT_METHODREF
          Tag value for Method Reference 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
ConstantPoolEntry(int tagValue, int entries)
          Initialise the constant pool entry.
 
Method Summary
 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
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.


Copyright 2000-2005 Apache Software Foundation. All Rights Reserved.