Method Detail

• getCount

  int getCount(Object object)

  Returns the number of occurrences of the given object currently in the MultiSet. If the object does not exist in the multiset, return 0.

  Parameters:

  object - the object to search for

  Returns:

  the number of occurrences of the object, zero if not found

• setCount

  int setCount(E object,
               int count)

  Sets the number of occurrences of the specified object in the MultiSet to the given count.

  If the provided count is zero, the object will be removed from the uniqueSet().

  Parameters:

  object - the object to update

  count - the number of occurrences of the object

  Returns:

  the number of occurrences of the object before this operation, zero if the object was not contained in the multiset

  Throws:

  IllegalArgumentException - if count is negative

• add

  boolean add(E object)

  Adds one copy of the specified object to the MultiSet.

  If the object is already in the uniqueSet() then increment its count as reported by getCount(Object). Otherwise add it to the uniqueSet() and report its count as 1.

  Specified by:

  add in interface  Collection<E>

  Parameters:

  object - the object to add

  Returns:

  true always, as the size of the MultiSet is increased in any case

• add

  int add(E object,
          int occurrences)

  Adds a number of occurrences of the specified object to the MultiSet.

  If the object is already in the uniqueSet() then increment its count as reported by getCount(Object). Otherwise add it to the uniqueSet() and report its count as occurrences.

  Parameters:

  object - the object to add

  occurrences - the number of occurrences to add, may be zero, in which case no change is made to the multiset

  Returns:

  the number of occurrences of the object in the multiset before this operation; possibly zero

  Throws:

  IllegalArgumentException - if occurrences is negative

• remove

  boolean remove(Object object)

  Removes one occurrence of the given object from the MultiSet.

  If the number of occurrences after this operations is reduced to zero, the object will be removed from the uniqueSet().

  Specified by:

  remove in interface  Collection<E>

  Parameters:

  object - the object to remove

  Returns:

  true if this call changed the collection

• remove

  int remove(Object object,
             int occurrences)

  Removes a number of occurrences of the specified object from the MultiSet.

  If the number of occurrences to remove is greater than the actual number of occurrences in the multiset, the object will be removed from the multiset.

  Parameters:

  object - the object to remove

  occurrences - the number of occurrences to remove, may be zero, in which case no change is made to the multiset

  Returns:

  the number of occurrences of the object in the multiset before the operation; possibly zero

  Throws:

  IllegalArgumentException - if occurrences is negative

• uniqueSet

  Set<E> uniqueSet()

  Returns a Set of unique elements in the MultiSet.

  Uniqueness constraints are the same as those in Set.

  The returned set is backed by this multiset, so any change to either is immediately reflected in the other. Only removal operations are supported, in which case all occurrences of the element are removed from the backing multiset.

  Returns:

  the Set of unique MultiSet elements

• entrySet

  Set<MultiSet.Entry<E>> entrySet()

  Returns a Set of all entries contained in the MultiSet.

  The returned set is backed by this multiset, so any change to either is immediately reflected in the other.

  Returns:

  the Set of MultiSet entries

• iterator

  Iterator<E> iterator()

  Returns an Iterator over the entire set of members, including copies due to cardinality. This iterator is fail-fast and will not tolerate concurrent modifications.

  Specified by:

  iterator in interface  Collection<E>

  Specified by:

  iterator in interface  Iterable<E>

  Returns:

  iterator over all elements in the MultiSet

• size

  int size()

  Returns the total number of items in the MultiSet.

  Specified by:

  size in interface  Collection<E>

  Returns:

  the total size of the multiset

• containsAll

  boolean containsAll(Collection<?> coll)

  Returns true if the MultiSet contains at least one occurrence for each element contained in the given collection.

  Specified by:

  containsAll in interface  Collection<E>

  Parameters:

  coll - the collection to check against

  Returns:

  true if the MultiSet contains all the collection

• removeAll

  boolean removeAll(Collection<?> coll)

  Remove all occurrences of all elements from this MultiSet represented in the given collection.

  Specified by:

  removeAll in interface  Collection<E>

  Parameters:

  coll - the collection of elements to remove

  Returns:

  true if this call changed the multiset

• retainAll

  boolean retainAll(Collection<?> coll)

  Remove any elements of this MultiSet that are not contained in the given collection.

  Specified by:

  retainAll in interface  Collection<E>

  Parameters:

  coll - the collection of elements to retain

  Returns:

  true if this call changed the multiset

• equals

  boolean equals(Object obj)

  Compares this MultiSet to another object.

  This MultiSet equals another object if it is also a MultiSet that contains the same number of occurrences of the same elements.

  Specified by:

  equals in interface  Collection<E>

  Overrides:

  equals in class  Object

  Parameters:

  obj - the object to compare to

  Returns:

  true if equal

• hashCode

  int hashCode()

  Gets a hash code for the MultiSet compatible with the definition of equals. The hash code is defined as the sum total of a hash code for each element. The per element hash code is defined as (e==null ? 0 : e.hashCode()) ^ noOccurances).

  Specified by:

  hashCode in interface  Collection<E>

  Overrides:

  hashCode in class  Object

  Returns:

  the hash code of the MultiSet