java.lang.Object java.util.AbstractCollection<E> java.util.AbstractSet
The process of implementing a set by extending this class is identical to that of implementing a Collection by extending AbstractCollection, except that all of the methods and constructors in subclasses of this class must obey the additional constraints imposed by the Set interface (for instance, the add method must not permit addition of multiple instances of an object to a set).
Note that this class does not override any of the implementations from the AbstractCollection class. It merely adds implementations for equals and hashCode.
This class is a member of the Java Collections Framework.
- the type of elements maintained by this set
|Method from java.util.AbstractSet Summary:|
|equals, hashCode, removeAll|
|Methods from java.util.AbstractCollection:|
|add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray, toString|
|Methods from java.lang.Object:|
|clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait|
|Method from java.util.AbstractSet Detail:|
This implementation first checks if the specified object is this set; if so it returns true. Then, it checks if the specified object is a set whose size is identical to the size of this set; if not, it returns false. If so, it returns containsAll((Collection) o).
public int hashCode()
This implementation iterates over the set, calling the hashCode method on each element in the set, and adding up the results.
public boolean removeAll(Collection<?> c)
This implementation determines which is the smaller of this set and the specified collection, by invoking the size method on each. If this set has fewer elements, then the implementation iterates over this set, checking each element returned by the iterator in turn to see if it is contained in the specified collection. If it is so contained, it is removed from this set with the iterator's remove method. If the specified collection has fewer elements, then the implementation iterates over the specified collection, removing from this set each element returned by the iterator, using this set's remove method.
Note that this implementation will throw an UnsupportedOperationException if the iterator returned by the iterator method does not implement the remove method.