Package org.apache.jackrabbit.util

Class WeakIdentityCollection

java.lang.Object
org.apache.jackrabbit.util.WeakIdentityCollection
All Implemented Interfaces:
Iterable, Collection
public class WeakIdentityCollection extends Object implements Collection
WeakIdentityCollection implements a Collection with weak values. Equality of elements is tested using the == operator.

This collection does not hide the fact that the garbage collector will remove a mapping at some point in time. Thus, the Iterator returned by this collection might return null values. The same applies to the method toArray() in both its variants.

  • Constructor Details

    • WeakIdentityCollection

      public WeakIdentityCollection(int initialCapacity)
      Creates a new WeakIdentityCollection.
      Parameters:
      initialCapacity - the initial capacity.

  • Method Details

    • size

      public int size()
      Returns the current size of this collection.
      Specified by:
      size in interface Collection
      Returns:
      the current size of this collection.

    • isEmpty

      public boolean isEmpty()
      Returns true if this collection is empty.
      Specified by:
      isEmpty in interface Collection
      Returns:
      true if this collection is empty.

    • clear

      public void clear()
      Releases all references held by this collection.
      Specified by:
      clear in interface Collection

    • add

      public boolean add(Object o)
      Adds object o to this collection.
      Specified by:
      add in interface Collection
      Parameters:
      o - the object to add.
      Returns:
      always true as this collection allows duplicates.
      Throws:
      NullPointerException - if o is null.

    • contains

      public boolean contains(Object o)
      Returns true if this collection contains o.
      Specified by:
      contains in interface Collection
      Parameters:
      o - element whose presence in this collection is to be tested.
      Returns:
      true if this collection contains the specified element

    • remove

      public boolean remove(Object o)
      Removes the object o from this collection if it is present.
      Specified by:
      remove in interface Collection
      Parameters:
      o - the object to remove.
      Returns:
      true if this collection changed as a result of the call.

    • addAll

      public boolean addAll(Collection c)
      Specified by:
      addAll in interface Collection
      Throws:
      UnsupportedOperationException - always.

    • containsAll

      public boolean containsAll(Collection c)
      Specified by:
      containsAll in interface Collection
      Throws:
      UnsupportedOperationException - always.

    • removeAll

      public boolean removeAll(Collection c)
      Specified by:
      removeAll in interface Collection
      Throws:
      UnsupportedOperationException - always.

    • retainAll

      public boolean retainAll(Collection c)
      Specified by:
      retainAll in interface Collection
      Throws:
      UnsupportedOperationException - always.

    • iterator

      public Iterator iterator()
      Returns an Iterator over the elements of this collection. The returned iterator is not fail-fast. That is, it does not throw a ConcurrentModificationException if this collection is modified while iterating over the collection.
      Specified by:
      iterator in interface Collection
      Specified by:
      iterator in interface Iterable
      Returns:
      an Iterator over the elements of this collection.

    • toArray

      public Object[] toArray()
      Returns an array containing all of the elements in this collection. The returned array may contain null elements!
      Specified by:
      toArray in interface Collection
      Returns:
      an array containing all of the elements in this collection.

    • toArray

      public Object[] toArray(Object[] a)
      The returned array may contain null elements!
      Specified by:
      toArray in interface Collection