Package org.apache.commons.collections4.bag

Class SynchronizedBag<E>

java.lang.Object
org.apache.commons.collections4.collection.SynchronizedCollection<E>
org.apache.commons.collections4.bag.SynchronizedBag<E>
Type Parameters:
E - the type of elements in this bag
All Implemented Interfaces:
Serializable, Iterable<E>, Collection<E>, Bag<E>
Direct Known Subclasses:
SynchronizedSortedBag
public class SynchronizedBag<E> extends SynchronizedCollection<E> implements Bag<E>
Decorates another Bag to synchronize its behavior for a multithreaded environment.

Methods are synchronized, then forwarded to the decorated bag. Iterators must be separately synchronized around the loop.

This class is Serializable from Commons Collections 3.1.

Since:
3.0
See Also:

  • Constructor Details

    • SynchronizedBag

      protected SynchronizedBag(Bag<E> bag)
      Constructor that wraps (not copies).
      Parameters:
      bag - the bag to decorate, must not be null
      Throws:
      NullPointerException - if bag is null

    • SynchronizedBag

      protected SynchronizedBag(Bag<E> bag, Object lock)
      Constructor that wraps (not copies).
      Parameters:
      bag - the bag to decorate, must not be null
      lock - the lock to use, must not be null
      Throws:
      NullPointerException - if bag or lock is null

  • Method Details

    • synchronizedBag

      public static <E> SynchronizedBag<E> synchronizedBag(Bag<E> bag)
      Factory method to create a synchronized bag.
      Type Parameters:
      E - the type of the elements in the bag
      Parameters:
      bag - the bag to decorate, must not be null
      Returns:
      a new synchronized Bag
      Throws:
      NullPointerException - if bag is null
      Since:
      4.0

    • add

      public boolean add(E object, int count)
      Description copied from interface: Bag
      Adds nCopies copies of the specified object to the Bag.

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

      Specified by:
      add in interface Bag<E>
      Parameters:
      object - the object to add
      count - the number of copies to add
      Returns:
      true if the object was not already in the uniqueSet

    • equals

      public boolean equals(Object object)
      Specified by:
      equals in interface Collection<E>
      Overrides:
      equals in class SynchronizedCollection<E>

    • getBag

      protected Bag<E> getBag()
      Gets the bag being decorated.
      Returns:
      the decorated bag

    • getCount

      public int getCount(Object object)
      Description copied from interface: Bag
      Returns the number of occurrences (cardinality) of the given object currently in the bag. If the object does not exist in the bag, return 0.
      Specified by:
      getCount in interface Bag<E>
      Parameters:
      object - the object to search for
      Returns:
      the number of occurrences of the object, zero if not found

    • hashCode

      public int hashCode()
      Specified by:
      hashCode in interface Collection<E>
      Overrides:
      hashCode in class SynchronizedCollection<E>

    • remove

      public boolean remove(Object object, int count)
      Description copied from interface: Bag
      Removes nCopies copies of the specified object from the Bag.

      If the number of copies to remove is greater than the actual number of copies in the Bag, no error is thrown.

      Specified by:
      remove in interface Bag<E>
      Parameters:
      object - the object to remove
      count - the number of copies to remove
      Returns:
      true if this call changed the collection

    • uniqueSet

      public Set<E> uniqueSet()
      Description copied from interface: Bag
      Returns a Set of unique elements in the Bag.

      Uniqueness constraints are the same as those in Set.

      Specified by:
      uniqueSet in interface Bag<E>
      Returns:
      the Set of unique Bag elements