HashBag

Class Overview

Implements Bag, using a HashMap to provide the data storage. This is the standard implementation of a bag.

A Bag stores each object in the collection together with a count of occurrences. Extra methods on the interface allow multiple copies of an object to be added or removed at once. It is important to read the interface javadoc carefully as several methods violate the Collection interface specification.

Summary

[Expand] Inherited Methods
From class org.apache.commons.collections.bag.AbstractMapBag boolean add(Object object, int nCopies) Adds a new element to the bag, incrementing its count in the map. boolean add(Object object) Adds a new element to the bag, incrementing its count in the underlying map. boolean addAll(Collection coll) Invokes add(Object) for each element in the given collection. void clear() Clears the bag by clearing the underlying map. boolean contains(Object object) Determines if the bag contains the given element by checking if the underlying map contains the element as a key. boolean containsAll(Collection coll) Determines if the bag contains the given elements. void doReadObject(Map map, ObjectInputStream in) Read the map in using a custom routine. void doWriteObject(ObjectOutputStream out) Write the map out using a custom routine. boolean equals(Object object) Compares this Bag to another. int getCount(Object object) Returns the number of occurrence of the given element in this bag by looking up its count in the underlying map. Map getMap() Utility method for implementations to access the map that backs this bag. int hashCode() Gets a hash code for the Bag compatible with the definition of equals. boolean isEmpty() Returns true if the underlying map is empty. Iterator iterator() Gets an iterator over the bag elements. boolean remove(Object object, int nCopies) Removes a specified number of copies of an object from the bag. boolean remove(Object object) Removes all copies of the specified object from the bag. boolean removeAll(Collection coll) Removes objects from the bag according to their count in the specified collection. boolean retainAll(Collection coll) Remove any members of the bag that are not in the given bag, respecting cardinality. int size() Returns the number of elements in this bag. Object[] toArray() Returns an array of all of this bag's elements. Object[] toArray(Object[] array) Returns an array of all of this bag's elements. String toString() Implement a toString() method suitable for debugging. Set uniqueSet() Returns an unmodifiable view of the underlying map's key set.
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait() final void wait(long arg0, int arg1) final void wait(long arg0)
From interface java.lang.Iterable abstract Iterator<T> iterator()
From interface java.util.Collection abstract boolean add(E arg0) abstract boolean addAll(Collection<? extends E> arg0) abstract void clear() abstract boolean contains(Object arg0) abstract boolean containsAll(Collection<?> arg0) abstract boolean equals(Object arg0) abstract int hashCode() abstract boolean isEmpty() abstract Iterator<E> iterator() abstract boolean remove(Object arg0) abstract boolean removeAll(Collection<?> arg0) abstract boolean retainAll(Collection<?> arg0) abstract int size() abstract <T> T[] toArray(T[] arg0) abstract Object[] toArray()
From interface org.apache.commons.collections.Bag abstract boolean add(Object object, int nCopies) Adds nCopies copies of the specified object to the Bag. abstract boolean add(Object object) (Violation) Adds one copy the specified object to the Bag. abstract boolean containsAll(Collection coll) (Violation) Returns true if the bag contains all elements in the given collection, respecting cardinality. abstract int getCount(Object object) Returns the number of occurrences (cardinality) of the given object currently in the bag. abstract Iterator iterator() Returns an Iterator over the entire set of members, including copies due to cardinality. abstract boolean remove(Object object) (Violation) Removes all occurrences of the given object from the bag. abstract boolean remove(Object object, int nCopies) Removes nCopies copies of the specified object from the Bag. abstract boolean removeAll(Collection coll) (Violation) Remove all elements represented in the given collection, respecting cardinality. abstract boolean retainAll(Collection coll) (Violation) Remove any members of the bag that are not in the given collection, respecting cardinality. abstract int size() Returns the total number of items in the bag across all types. abstract Set uniqueSet() Returns a Set of unique elements in the Bag.