--- jsr166/src/main/java/util/Deque.java 2012/10/21 06:40:20 1.21 +++ jsr166/src/main/java/util/Deque.java 2017/08/23 20:17:53 1.40 @@ -9,7 +9,7 @@ package java.util; /** * A linear collection that supports element insertion and removal at * both ends. The name deque is short for "double ended queue" - * and is usually pronounced "deck". Most Deque + * and is usually pronounced "deck". Most {@code Deque} * implementations place no fixed limits on the number of elements * they may contain, but this interface supports capacity-restricted * deques as well as those with no fixed size limit. @@ -18,114 +18,125 @@ package java.util; * ends of the deque. Methods are provided to insert, remove, and * examine the element. Each of these methods exists in two forms: * one throws an exception if the operation fails, the other returns a - * special value (either null or false, depending on + * special value (either {@code null} or {@code false}, depending on * the operation). The latter form of the insert operation is * designed specifically for use with capacity-restricted - * Deque implementations; in most implementations, insert + * {@code Deque} implementations; in most implementations, insert * operations cannot fail. * *
The twelve methods described above are summarized in the * following table: * - *
- *
- * | First Element (Head) | - *Last Element (Tail) | + *+ * | First Element (Head) | + *Last Element (Tail) | *||||
---|---|---|---|---|---|---|---|---|---|
- * | Throws exception | - *Special value | - *Throws exception | - *Special value | + *Throws exception | + *Special value | + *Throws exception | + *Special value | *|
Insert | - *{@link #addFirst addFirst(e)} | - *{@link #offerFirst offerFirst(e)} | - *{@link #addLast addLast(e)} | - *{@link #offerLast offerLast(e)} | + *Insert | + *{@link #addFirst(Object) addFirst(e)} | + *{@link #offerFirst(Object) offerFirst(e)} | + *{@link #addLast(Object) addLast(e)} | + *{@link #offerLast(Object) offerLast(e)} | *
Remove | - *{@link #removeFirst removeFirst()} | - *{@link #pollFirst pollFirst()} | - *{@link #removeLast removeLast()} | - *{@link #pollLast pollLast()} | + *Remove | + *{@link #removeFirst() removeFirst()} | + *{@link #pollFirst() pollFirst()} | + *{@link #removeLast() removeLast()} | + *{@link #pollLast() pollLast()} | *
Examine | - *{@link #getFirst getFirst()} | - *{@link #peekFirst peekFirst()} | - *{@link #getLast getLast()} | - *{@link #peekLast peekLast()} | + *Examine | + *{@link #getFirst() getFirst()} | + *{@link #peekFirst() peekFirst()} | + *{@link #getLast() getLast()} | + *{@link #peekLast() peekLast()} | *
This interface extends the {@link Queue} interface. When a deque is * used as a queue, FIFO (First-In-First-Out) behavior results. Elements are * added at the end of the deque and removed from the beginning. The methods - * inherited from the Queue interface are precisely equivalent to - * Deque methods as indicated in the following table: + * inherited from the {@code Queue} interface are precisely equivalent to + * {@code Deque} methods as indicated in the following table: * - *
- *
Queue Method | - *Equivalent Deque Method | + *{@code Queue} Method | + *Equivalent {@code Deque} Method | *
---|---|---|---|
{@link java.util.Queue#add add(e)} | - *{@link #addLast addLast(e)} | + *{@link #add(Object) add(e)} | + *{@link #addLast(Object) addLast(e)} | *
{@link java.util.Queue#offer offer(e)} | - *{@link #offerLast offerLast(e)} | + *{@link #offer(Object) offer(e)} | + *{@link #offerLast(Object) offerLast(e)} | *
{@link java.util.Queue#remove remove()} | - *{@link #removeFirst removeFirst()} | + *{@link #remove() remove()} | + *{@link #removeFirst() removeFirst()} | *
{@link java.util.Queue#poll poll()} | - *{@link #pollFirst pollFirst()} | + *{@link #poll() poll()} | + *{@link #pollFirst() pollFirst()} | *
{@link java.util.Queue#element element()} | - *{@link #getFirst getFirst()} | + *{@link #element() element()} | + *{@link #getFirst() getFirst()} | *
{@link java.util.Queue#peek peek()} | - *{@link #peek peekFirst()} | + *{@link #peek() peek()} | + *{@link #peekFirst() peekFirst()} | *
Deques can also be used as LIFO (Last-In-First-Out) stacks. This * interface should be used in preference to the legacy {@link Stack} class. * When a deque is used as a stack, elements are pushed and popped from the * beginning of the deque. Stack methods are precisely equivalent to - * Deque methods as indicated in the table below: + * {@code Deque} methods as indicated in the table below: * - *
- *
Stack Method | - *Equivalent Deque Method | + *Stack Method | + *Equivalent {@code Deque} Method | *
---|---|---|---|
{@link #push push(e)} | - *{@link #addFirst addFirst(e)} | + *{@link #push(Object) push(e)} | + *{@link #addFirst(Object) addFirst(e)} | *
{@link #pop pop()} | - *{@link #removeFirst removeFirst()} | + *{@link #pop() pop()} | + *{@link #removeFirst() removeFirst()} | *
{@link #peek peek()} | - *{@link #peekFirst peekFirst()} | + *{@link #peek() peek()} | + *{@link #peekFirst() peekFirst()} | *
Note that the {@link #peek peek} method works equally well when @@ -139,34 +150,35 @@ package java.util; *
Unlike the {@link List} interface, this interface does not * provide support for indexed access to elements. * - *
While Deque implementations are not strictly required + *
While {@code Deque} implementations are not strictly required * to prohibit the insertion of null elements, they are strongly - * encouraged to do so. Users of any Deque implementations + * encouraged to do so. Users of any {@code Deque} implementations * that do allow null elements are strongly encouraged not to * take advantage of the ability to insert nulls. This is so because - * null is used as a special return value by various methods - * to indicated that the deque is empty. + * {@code null} is used as a special return value by various methods + * to indicate that the deque is empty. * - *
Deque implementations generally do not define - * element-based versions of the equals and hashCode + *
{@code Deque} implementations generally do not define + * element-based versions of the {@code equals} and {@code hashCode} * methods, but instead inherit the identity-based versions from class - * Object. + * {@code Object}. * - *
This interface is a member of the Java Collections - * Framework. + *
This interface is a member of the
+ *
+ * Java Collections Framework.
*
* @author Doug Lea
* @author Josh Bloch
* @since 1.6
- * @param This method is equivalent to {@link #add}.
*
@@ -207,8 +220,8 @@ public interface Deque This method is equivalent to {@link #addLast}.
*
* @param e the element to add
- * @return true (as specified by {@link Collection#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
@@ -375,7 +390,7 @@ public interface Deque This method is equivalent to {@link #offerLast}.
*
* @param e the element to add
- * @return true if the element was added to this deque, else
- * false
+ * @return {@code true} if the element was added to this deque, else
+ * {@code false}
* @throws ClassCastException if the class of the specified element
* prevents it from being added to this deque
* @throws NullPointerException if the specified element is null and this
@@ -397,8 +412,8 @@ public interface Deque This method is equivalent to {@link #removeFirst()}.
*
@@ -410,11 +425,11 @@ public interface Deque This method is equivalent to {@link #pollFirst()}.
*
- * @return the first element of this deque, or null if
+ * @return the first element of this deque, or {@code null} if
* this deque is empty
*/
E poll();
@@ -435,24 +450,48 @@ public interface Deque This method is equivalent to {@link #peekFirst()}.
*
* @return the head of the queue represented by this deque, or
- * null if this deque is empty
+ * {@code null} if this deque is empty
*/
E peek();
+ /**
+ * Adds all of the elements in the specified collection at the end
+ * of this deque, as if by calling {@link #addLast} on each one,
+ * in the order that they are returned by the collection's iterator.
+ *
+ * When using a capacity-restricted deque, it is generally preferable
+ * to call {@link #offer(Object) offer} separately on each element.
+ *
+ * An exception encountered while trying to add an element may result
+ * in only some of the elements having been successfully added when
+ * the associated exception is thrown.
+ *
+ * @param c the elements to be inserted into this deque
+ * @return {@code true} if this deque changed as a result of the call
+ * @throws IllegalStateException if not all the elements can be added at
+ * this time due to insertion restrictions
+ * @throws ClassCastException if the class of an element of the specified
+ * collection prevents it from being added to this deque
+ * @throws NullPointerException if the specified collection contains a
+ * null element and this deque 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 deque
+ */
+ boolean addAll(Collection extends E> c);
// *** Stack methods ***
/**
* Pushes an element onto the stack represented by this deque (in other
* words, at the head of this deque) if it is possible to do so
- * immediately without violating capacity restrictions, returning
- * true upon success and throwing an
- * IllegalStateException if no space is currently available.
+ * immediately without violating capacity restrictions, throwing an
+ * {@code IllegalStateException} if no space is currently available.
*
* This method is equivalent to {@link #addFirst}.
*
@@ -486,35 +525,37 @@ public interface Deque This method is equivalent to {@link #removeFirstOccurrence}.
+ * This method is equivalent to {@link #removeFirstOccurrence(Object)}.
*
* @param o element to be removed from this deque, if present
- * @return true if an element was removed as a result of this call
+ * @return {@code true} if an element was removed as a result of this call
* @throws ClassCastException if the class of the specified element
- * is incompatible with this deque (optional)
+ * is incompatible with this deque
+ * (optional)
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements (optional)
+ * deque does not permit null elements
+ * (optional)
*/
boolean remove(Object o);
/**
- * Returns true if this deque contains the specified element.
- * More formally, returns true if and only if this deque contains
- * at least one element e such that
- * (o==null ? e==null : o.equals(e)).
+ * Returns {@code true} if this deque contains the specified element.
+ * More formally, returns {@code true} if and only if this deque contains
+ * at least one element {@code e} such that {@code Objects.equals(o, e)}.
*
* @param o element whose presence in this deque is to be tested
- * @return true if this deque contains the specified element
- * @throws ClassCastException if the type of the specified element
- * is incompatible with this deque (optional)
+ * @return {@code true} if this deque contains the specified element
+ * @throws ClassCastException if the class of the specified element
+ * is incompatible with this deque
+ * (optional)
* @throws NullPointerException if the specified element is null and this
- * deque does not permit null elements (optional)
+ * deque does not permit null elements
+ * (optional)
*/
boolean contains(Object o);
@@ -523,7 +564,7 @@ public interface Deque