serp.util
Class ReferenceCollection

java.lang.Object
  |
  +--serp.util.ReferenceCollection

All Implemented Interfaces:

Collection

public class ReferenceCollection

extends Object

implements Collection

A collection whose values may be stored as weak or soft references.

Expired values are removed from the collection before any mutator methods; removing before accessor methods can lead to ConcurrentModificationExceptions. Thus, the following methods may produce results which include values that have expired:

• size
• isEmpty

By default, all methods are delegated to the internal collection provided at construction. Thus, the ordering, etc of the given collection will be preserved. A special case is also made for MapSets using identity hashing, which is supported. Performance is similar to that of the internal collection instance.

Field Summary

static int	HARD Hard reference marker.
static int	SOFT Soft reference marker.
static int	WEAK Weak reference marker.

Constructor Summary

ReferenceCollection()
Equivalent to ReferenceCollection (ReferenceCollection.HARD).

ReferenceCollection(int defaultType)
Equivalent to ReferenceCollection (defaultType, new LinkedList ()).

ReferenceCollection(int defaultType, Collection coll)
Construct a ReferenceCollection with the given default reference type and interal collection.

Method Summary

boolean	add(Object obj)
boolean	add(Object obj, int type)
boolean	addAll(Collection objs)
void	clear()
boolean	contains(Object obj)
boolean	containsAll(Collection objs)
boolean	equals(Object other)
boolean	isEmpty()
Iterator	iterator()
boolean	remove(Object obj)
boolean	removeAll(Collection objs)
boolean	retainAll(Collection objs)
int	size()
Object[]	toArray()
Object[]	toArray(Object[] a)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

hashCode

Field Detail

HARD

public static final int HARD

Hard reference marker.

SOFT

public static final int SOFT

Soft reference marker.

WEAK

public static final int WEAK

Weak reference marker.

Constructor Detail

ReferenceCollection

public ReferenceCollection()

Equivalent to ReferenceCollection (ReferenceCollection.HARD).

ReferenceCollection

public ReferenceCollection(int defaultType)

Equivalent to ReferenceCollection (defaultType, new LinkedList ()).

ReferenceCollection

public ReferenceCollection(int defaultType,
                           Collection coll)

Construct a ReferenceCollection with the given default reference type and interal collection. The internal collection will be cleared. It should not be accessed in any way after being given to this constructor; this collection will 'inherit' its behavior, however. For example, if the given collection is a TreeSet, the elements will be maintained in natural order and will not allow duplicates.

Method Detail

add

public boolean add(Object obj)

Specified by:

add in interface Collection

add

public boolean add(Object obj,
                   int type)

addAll

public boolean addAll(Collection objs)

Specified by:

addAll in interface Collection

clear

public void clear()

Specified by:

clear in interface Collection

contains

public boolean contains(Object obj)

Specified by:

contains in interface Collection

containsAll

public boolean containsAll(Collection objs)

Specified by:

containsAll in interface Collection

equals

public boolean equals(Object other)

Specified by:

equals in interface Collection

Overrides:

equals in class Object

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection

remove

public boolean remove(Object obj)

Specified by:

remove in interface Collection

removeAll

public boolean removeAll(Collection objs)

Specified by:

removeAll in interface Collection

retainAll

public boolean retainAll(Collection objs)

Specified by:

retainAll in interface Collection

size

public int size()

Specified by:

size in interface Collection

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection

toArray

public Object[] toArray(Object[] a)

Specified by:

toArray in interface Collection

iterator

public Iterator iterator()

Specified by:

iterator in interface Collection