diff -r 5be31d9fa455 -r d382dacfd73f rt/emul/compact/src/main/java/java/util/AbstractCollection.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/rt/emul/compact/src/main/java/java/util/AbstractCollection.java Tue Feb 26 16:54:16 2013 +0100 @@ -0,0 +1,457 @@ +/* + * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. Oracle designates this + * particular file as subject to the "Classpath" exception as provided + * by Oracle in the LICENSE file that accompanied this code. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +package java.util; + +/** + * This class provides a skeletal implementation of the Collection + * interface, to minimize the effort required to implement this interface.

+ * + * 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 implements Collection { + /** + * Sole constructor. (For invocation by subclass constructors, typically + * implicit.) + */ + protected AbstractCollection() { + } + + // Query Operations + + /** + * Returns an iterator over the elements contained in this collection. + * + * @return an iterator over the elements contained in this collection + */ + public abstract Iterator iterator(); + + public abstract int size(); + + /** + * {@inheritDoc} + * + *

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 it = iterator(); + if (o==null) { + while (it.hasNext()) + if (it.next()==null) + return true; + } else { + while (it.hasNext()) + if (o.equals(it.next())) + return true; + } + return false; + } + + /** + * {@inheritDoc} + * + *

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: + * + *

 {@code
+     * List list = new ArrayList(size());
+     * for (E e : this)
+     *     list.add(e);
+     * return list.toArray();
+     * }
+ */ + public Object[] toArray() { + // Estimate size of array; be prepared to see more or fewer elements + Object[] r = new Object[size()]; + Iterator it = iterator(); + for (int i = 0; i < r.length; i++) { + if (! it.hasNext()) // fewer elements than expected + return Arrays.copyOf(r, i); + r[i] = it.next(); + } + return it.hasNext() ? finishToArray(r, it) : r; + } + + /** + * {@inheritDoc} + * + *

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: + * + *

 {@code
+     * List list = new ArrayList(size());
+     * for (E e : this)
+     *     list.add(e);
+     * return list.toArray(a);
+     * }
+ * + * @throws ArrayStoreException {@inheritDoc} + * @throws NullPointerException {@inheritDoc} + */ + public T[] toArray(T[] a) { + // Estimate size of array; be prepared to see more or fewer elements + int size = size(); + T[] r = a.length >= size ? a : + (T[])java.lang.reflect.Array + .newInstance(a.getClass().getComponentType(), size); + Iterator it = iterator(); + + for (int i = 0; i < r.length; i++) { + if (! it.hasNext()) { // fewer elements than expected + if (a != r) + return Arrays.copyOf(r, i); + r[i] = null; // null-terminate + return r; + } + r[i] = (T)it.next(); + } + return it.hasNext() ? finishToArray(r, it) : r; + } + + /** + * The maximum size of array to allocate. + * Some VMs reserve some header words in an array. + * Attempts to allocate larger arrays may result in + * OutOfMemoryError: Requested array size exceeds VM limit + */ + private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; + + /** + * Reallocates the array being used within toArray when the iterator + * returned more elements than expected, and finishes filling it from + * the iterator. + * + * @param r the array, replete with previously stored elements + * @param it the in-progress iterator over this collection + * @return array containing the elements in the given array, plus any + * further elements returned by the iterator, trimmed to size + */ + private static T[] finishToArray(T[] r, Iterator it) { + int i = r.length; + while (it.hasNext()) { + int cap = r.length; + if (i == cap) { + int newCap = cap + (cap >> 1) + 1; + // overflow-conscious code + if (newCap - MAX_ARRAY_SIZE > 0) + newCap = hugeCapacity(cap + 1); + r = Arrays.copyOf(r, newCap); + } + r[i++] = (T)it.next(); + } + // trim if overallocated + return (i == r.length) ? r : Arrays.copyOf(r, i); + } + + private static int hugeCapacity(int minCapacity) { + if (minCapacity < 0) // overflow + throw new OutOfMemoryError + ("Required array size too large"); + return (minCapacity > MAX_ARRAY_SIZE) ? + Integer.MAX_VALUE : + MAX_ARRAY_SIZE; + } + + // Modification Operations + + /** + * {@inheritDoc} + * + *

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 it = iterator(); + if (o==null) { + while (it.hasNext()) { + if (it.next()==null) { + it.remove(); + return true; + } + } + } else { + while (it.hasNext()) { + if (o.equals(it.next())) { + it.remove(); + return true; + } + } + } + return false; + } + + + // Bulk Operations + + /** + * {@inheritDoc} + * + *

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 it = iterator(); + while (it.hasNext()) { + if (!c.contains(it.next())) { + it.remove(); + modified = true; + } + } + return modified; + } + + /** + * {@inheritDoc} + * + *

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 it = iterator(); + while (it.hasNext()) { + it.next(); + it.remove(); + } + } + + + // String conversion + + /** + * Returns a string representation of this collection. The string + * representation consists of a list of the collection's elements in the + * order they are returned by its iterator, enclosed in square brackets + * ("[]"). Adjacent elements are separated by the characters + * ", " (comma and space). Elements are converted to strings as + * by {@link String#valueOf(Object)}. + * + * @return a string representation of this collection + */ + public String toString() { + Iterator it = iterator(); + if (! it.hasNext()) + return "[]"; + + StringBuilder sb = new StringBuilder(); + sb.append('['); + for (;;) { + E e = it.next(); + sb.append(e == this ? "(this Collection)" : e); + if (! it.hasNext()) + return sb.append(']').toString(); + sb.append(',').append(' '); + } + } + +}