com.triactive.jdo.util
Class InternPool

java.lang.Object
  java.util.AbstractCollection
      com.triactive.jdo.util.InternPool

All Implemented Interfaces:

java.util.Collection

public class InternPool

extends java.util.AbstractCollection

Implements a pool of internalized objects. Used to implement pools that behave like the one used by String.intern().

This implementation is synchronized. It is a generic collection that is unmodifiable with the exception of the intern(java.lang.Object) method.

Author:

Mike Martin

Constructor Summary

InternPool()

Method Summary

boolean	contains(java.lang.Object o)
java.lang.Object	intern(java.lang.Object candidate) Returns a canonical representation for the specified object.
java.util.Iterator	iterator()
int	size()

Methods inherited from class java.util.AbstractCollection

add, addAll, clear, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

equals, hashCode

Constructor Detail

InternPool

public InternPool()

Method Detail

intern

public java.lang.Object intern(java.lang.Object candidate)

Returns a canonical representation for the specified object.

This method behaves much like String.intern(). A pool of objects, initially empty, is maintained privately.

If the pool already contains an object equal to the specified object as determined by the equals(Object) method, then the object from the pool is returned. Otherwise, the specified object is added to the pool and a reference to the specified object is returned.

It follows that for any two objects o1 and o2, intern(o1) == intern(o2) is true if and only if o1.equals(o2) is true.

Parameters:

candidate - the object to internalize

Returns:

an object that is equivalent to the specified object, but is guaranteed to be from a pool of unique objects.

contains

public boolean contains(java.lang.Object o)

iterator

public java.util.Iterator iterator()

size

public int size()