--- jsr166/src/main/java/util/AbstractQueue.java	2005/05/02 08:35:49	1.27
+++ jsr166/src/main/java/util/AbstractQueue.java	2014/12/02 05:48:28	1.39
@@ -1,7 +1,7 @@
 /*
  * Written by Doug Lea with assistance from members of JCP JSR-166
  * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
+ * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
 package java.util;
@@ -9,29 +9,28 @@ package java.util;
 /**
  * This class provides skeletal implementations of some {@link Queue}
  * operations. The implementations in this class are appropriate when
- * the base implementation does <em>not</em> allow <tt>null</tt>
+ * the base implementation does <em>not</em> allow {@code null}
  * elements.  Methods {@link #add add}, {@link #remove remove}, and
  * {@link #element element} are based on {@link #offer offer}, {@link
- * #poll poll}, and {@link #peek peek}, respectively but throw
- * exceptions instead of indicating failure via <tt>false</tt> or
- * <tt>null</tt> returns.
+ * #poll poll}, and {@link #peek peek}, respectively, but throw
+ * exceptions instead of indicating failure via {@code false} or
+ * {@code null} returns.
  *
- * <p> A <tt>Queue</tt> implementation that extends this class must
+ * <p>A {@code Queue} implementation that extends this class must
  * minimally define a method {@link Queue#offer} which does not permit
- * insertion of <tt>null</tt> elements, along with methods {@link
- * Queue#peek}, {@link Queue#poll}, {@link Collection#size}, and a
- * {@link Collection#iterator} supporting {@link
- * Iterator#remove}. Typically, additional methods will be overridden
- * as well. If these requirements cannot be met, consider instead
- * subclassing {@link AbstractCollection}.
+ * insertion of {@code null} elements, along with methods {@link
+ * Queue#peek}, {@link Queue#poll}, {@link Collection#size}, and
+ * {@link Collection#iterator}.  Typically, additional methods will be
+ * overridden as well.  If these requirements cannot be met, consider
+ * instead subclassing {@link AbstractCollection}.
  *
  * <p>This class is a member of the
- * <a href="{@docRoot}/../guide/collections/index.html">
+ * <a href="{@docRoot}/../technotes/guides/collections/index.html">
  * Java Collections Framework</a>.
  *
  * @since 1.5
  * @author Doug Lea
- * @param <E> the type of elements held in this collection
+ * @param <E> the type of elements held in this queue
  */
 public abstract class AbstractQueue<E>
     extends AbstractCollection<E>
@@ -43,18 +42,25 @@ public abstract class AbstractQueue<E>
     protected AbstractQueue() {
     }
 
-
     /**
-     * Adds the specified element to this queue. This implementation
-     * returns <tt>true</tt> if <tt>offer</tt> succeeds, else
-     * throws an IllegalStateException.
-     *
-     * @param e the element
-     * @return <tt>true</tt> (as per the general contract of
-     *         <tt>Collection.add</tt>).
-     *
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     * @throws IllegalStateException if the element cannot be added.
+     * Inserts the specified element into this queue if it is possible to do so
+     * immediately without violating capacity restrictions, returning
+     * {@code true} upon success and throwing an {@code IllegalStateException}
+     * if no space is currently available.
+     *
+     * <p>This implementation returns {@code true} if {@code offer} succeeds,
+     * else throws an {@code IllegalStateException}.
+     *
+     * @param e the element to add
+     * @return {@code true} (as specified by {@link Collection#add})
+     * @throws IllegalStateException if the element cannot be added at this
+     *         time due to capacity restrictions
+     * @throws ClassCastException if the class of the specified element
+     *         prevents it from being added to this queue
+     * @throws NullPointerException if the specified element is null and
+     *         this queue does not permit null elements
+     * @throws IllegalArgumentException if some property of this element
+     *         prevents it from being added to this queue
      */
     public boolean add(E e) {
         if (offer(e))
@@ -64,12 +70,15 @@ public abstract class AbstractQueue<E>
     }
 
     /**
-     * Retrieves and removes the head of this queue.
-     * This implementation returns the result of <tt>poll</tt>
+     * Retrieves and removes the head of this queue.  This method differs
+     * from {@link #poll poll} only in that it throws an exception if this
+     * queue is empty.
+     *
+     * <p>This implementation returns the result of {@code poll}
      * unless the queue is empty.
      *
-     * @return the head of this queue.
-     * @throws NoSuchElementException if this queue is empty.
+     * @return the head of this queue
+     * @throws NoSuchElementException if this queue is empty
      */
     public E remove() {
         E x = poll();
@@ -80,12 +89,15 @@ public abstract class AbstractQueue<E>
     }
 
     /**
-     * Retrieves, but does not remove, the head of this queue.
-     * This implementation returns the result of <tt>peek</tt>
+     * Retrieves, but does not remove, the head of this queue.  This method
+     * differs from {@link #peek peek} only in that it throws an exception if
+     * this queue is empty.
+     *
+     * <p>This implementation returns the result of {@code peek}
      * unless the queue is empty.
      *
-     * @return the head of this queue.
-     * @throws NoSuchElementException if this queue is empty.
+     * @return the head of this queue
+     * @throws NoSuchElementException if this queue is empty
      */
     public E element() {
         E x = peek();
@@ -98,8 +110,9 @@ public abstract class AbstractQueue<E>
     /**
      * Removes all of the elements from this queue.
      * The queue will be empty after this call returns.
+     *
      * <p>This implementation repeatedly invokes {@link #poll poll} until it
-     * returns <tt>null</tt>.
+     * returns {@code null}.
      */
     public void clear() {
         while (poll() != null)
@@ -109,7 +122,7 @@ public abstract class AbstractQueue<E>
     /**
      * Adds all of the elements in the specified collection to this
      * queue.  Attempts to addAll of a queue to itself result in
-     * <tt>IllegalArgumentException</tt>. Further, the behavior of
+     * {@code IllegalArgumentException}. Further, the behavior of
      * this operation is undefined if the specified collection is
      * modified while the operation is in progress.
      *
@@ -117,17 +130,22 @@ public abstract class AbstractQueue<E>
      * and adds each element returned by the iterator to this
      * queue, in turn.  A runtime exception encountered while
      * trying to add an element (including, in particular, a
-     * <tt>null</tt> element) may result in only some of the elements
+     * {@code null} element) may result in only some of the elements
      * having been successfully added when the associated exception is
      * thrown.
      *
-     * @param c collection whose elements are to be added to this queue.
-     * @return <tt>true</tt> if this queue changed as a result of the
-     *         call.
-     * @throws NullPointerException if the specified collection or
-     *         any of its elements are null.
-     * @throws IllegalArgumentException if c is this queue.
-     *
+     * @param c collection containing elements to be added to this queue
+     * @return {@code true} if this queue changed as a result of the call
+     * @throws ClassCastException if the class of an element of the specified
+     *         collection prevents it from being added to this queue
+     * @throws NullPointerException if the specified collection contains a
+     *         null element and this queue does not permit null elements,
+     *         or if the specified collection is null
+     * @throws IllegalArgumentException if some property of an element of the
+     *         specified collection prevents it from being added to this
+     *         queue, or if the specified collection is this queue
+     * @throws IllegalStateException if not all the elements can be added at
+     *         this time due to insertion restrictions
      * @see #add(Object)
      */
     public boolean addAll(Collection<? extends E> c) {
@@ -136,11 +154,9 @@ public abstract class AbstractQueue<E>
         if (c == this)
             throw new IllegalArgumentException();
         boolean modified = false;
-        Iterator<? extends E> e = c.iterator();
-        while (e.hasNext()) {
-            if (add(e.next()))
+        for (E e : c)
+            if (add(e))
                 modified = true;
-        }
         return modified;
     }