- * - * To implement an unmodifiable collection, the programmer needs only to - * extend this class and provide implementations for the iterator and - * size methods. (The iterator returned by the iterator - * method must implement hasNext and next.)
- * - * To implement a modifiable collection, the programmer must additionally - * override this class's add method (which otherwise throws an - * UnsupportedOperationException), and the iterator returned by the - * iterator method must additionally implement its remove - * method.
- * - * The programmer should generally provide a void (no argument) and - * Collection constructor, as per the recommendation in the - * Collection interface specification.
- * - * The documentation for each non-abstract method in this class describes its - * implementation in detail. Each of these methods may be overridden if - * the collection being implemented admits a more efficient implementation.
- *
- * This class is a member of the
- *
- * Java Collections Framework.
- *
- * @author Josh Bloch
- * @author Neal Gafter
- * @see Collection
- * @since 1.2
- */
-
-public abstract class AbstractCollection This implementation returns size() == 0.
- */
- public boolean isEmpty() {
- return size() == 0;
- }
-
- /**
- * {@inheritDoc}
- *
- * This implementation iterates over the elements in the collection,
- * checking each element in turn for equality with the specified element.
- *
- * @throws ClassCastException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- */
- public boolean contains(Object o) {
- Iterator This implementation returns an array containing all the elements
- * returned by this collection's iterator, in the same order, stored in
- * consecutive elements of the array, starting with index {@code 0}.
- * The length of the returned array is equal to the number of elements
- * returned by the iterator, even if the size of this collection changes
- * during iteration, as might happen if the collection permits
- * concurrent modification during iteration. The {@code size} method is
- * called only as an optimization hint; the correct result is returned
- * even if the iterator returns a different number of elements.
- *
- * This method is equivalent to:
- *
- * This implementation returns an array containing all the elements
- * returned by this collection's iterator in the same order, stored in
- * consecutive elements of the array, starting with index {@code 0}.
- * If the number of elements returned by the iterator is too large to
- * fit into the specified array, then the elements are returned in a
- * newly allocated array with length equal to the number of elements
- * returned by the iterator, even if the size of this collection
- * changes during iteration, as might happen if the collection permits
- * concurrent modification during iteration. The {@code size} method is
- * called only as an optimization hint; the correct result is returned
- * even if the iterator returns a different number of elements.
- *
- * This method is equivalent to:
- *
- * This implementation always throws an
- * UnsupportedOperationException.
- *
- * @throws UnsupportedOperationException {@inheritDoc}
- * @throws ClassCastException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- * @throws IllegalArgumentException {@inheritDoc}
- * @throws IllegalStateException {@inheritDoc}
- */
- public boolean add(E e) {
- throw new UnsupportedOperationException();
- }
-
- /**
- * {@inheritDoc}
- *
- * This implementation iterates over the collection looking for the
- * specified element. If it finds the element, it removes the element
- * from the collection using the iterator's remove method.
- *
- * Note that this implementation throws an
- * UnsupportedOperationException if the iterator returned by this
- * collection's iterator method does not implement the remove
- * method and this collection contains the specified object.
- *
- * @throws UnsupportedOperationException {@inheritDoc}
- * @throws ClassCastException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- */
- public boolean remove(Object o) {
- Iterator This implementation iterates over the specified collection,
- * checking each element returned by the iterator in turn to see
- * if it's contained in this collection. If all elements are so
- * contained true is returned, otherwise false.
- *
- * @throws ClassCastException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- * @see #contains(Object)
- */
- public boolean containsAll(Collection c) {
- for (Object e : c)
- if (!contains(e))
- return false;
- return true;
- }
-
- /**
- * {@inheritDoc}
- *
- * This implementation iterates over the specified collection, and adds
- * each object returned by the iterator to this collection, in turn.
- *
- * Note that this implementation will throw an
- * UnsupportedOperationException unless add is
- * overridden (assuming the specified collection is non-empty).
- *
- * @throws UnsupportedOperationException {@inheritDoc}
- * @throws ClassCastException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- * @throws IllegalArgumentException {@inheritDoc}
- * @throws IllegalStateException {@inheritDoc}
- *
- * @see #add(Object)
- */
- public boolean addAll(Collection c) {
- boolean modified = false;
- for (E e : c)
- if (add(e))
- modified = true;
- return modified;
- }
-
- /**
- * {@inheritDoc}
- *
- * This implementation iterates over this collection, checking each
- * element returned by the iterator in turn to see if it's contained
- * in the specified collection. If it's so contained, it's removed from
- * this collection with the iterator'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
- * and this collection contains one or more elements in common with the
- * specified collection.
- *
- * @throws UnsupportedOperationException {@inheritDoc}
- * @throws ClassCastException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- *
- * @see #remove(Object)
- * @see #contains(Object)
- */
- public boolean removeAll(Collection c) {
- boolean modified = false;
- Iterator it = iterator();
- while (it.hasNext()) {
- if (c.contains(it.next())) {
- it.remove();
- modified = true;
- }
- }
- return modified;
- }
-
- /**
- * {@inheritDoc}
- *
- * This implementation iterates over this collection, checking each
- * element returned by the iterator in turn to see if it's contained
- * in the specified collection. If it's not so contained, it's removed
- * from this collection with the iterator'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
- * and this collection contains one or more elements not present in the
- * specified collection.
- *
- * @throws UnsupportedOperationException {@inheritDoc}
- * @throws ClassCastException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- *
- * @see #remove(Object)
- * @see #contains(Object)
- */
- public boolean retainAll(Collection c) {
- boolean modified = false;
- Iterator This implementation iterates over this collection, removing each
- * element using the Iterator.remove operation. Most
- * implementations will probably choose to override this method for
- * efficiency.
- *
- * Note that this implementation will throw an
- * UnsupportedOperationException if the iterator returned by this
- * collection's iterator method does not implement the
- * remove method and this collection is non-empty.
- *
- * @throws UnsupportedOperationException {@inheritDoc}
- */
- public void clear() {
- Iterator {@code
- * List
- */
- public Object[] toArray() {
- // Estimate size of array; be prepared to see more or fewer elements
- Object[] r = new Object[size()];
- Iterator {@code
- * List
- *
- * @throws ArrayStoreException {@inheritDoc}
- * @throws NullPointerException {@inheritDoc}
- */
- public