Queue, Stack, Deque, LinkedList

Stack是一个类。

class Stack extends Vector 

public class Vector
    extends AbstractList
    implements List, RandomAccess, Cloneable, java.io.Serializable

Queue是接口。定义如下方法：

public interface Queue extends Collection {
    boolean add(E e);
    boolean offer(E e);
    E remove();
    E poll();
    E element();
    E peek();
}

Deque是Queue的子接口，定义了如下方法：

public interface Deque extends Queue {
    void addFirst(E e);
    void addLast(E e);
    boolean offerFirst(E e);
    boolean offerLast(E e);
    E removeFirst();
    E removeLast();
    E pollFirst();
    E pollLast();
    E getFirst();
    E getLast();
    E peekFirst();
    E peekLast();
    boolean removeFirstOccurrence(Object o);
    boolean add(E e);
    boolean offer(E e);
    E remove();
    E poll();
    E element();
    E peek();
    void push(E e);
    E pop();
    boolean remove(Object o);
    boolean contains(Object o);
    public int size();
    Iterator iterator();
    Iterator descendingIterator();

LinkedList是Deque的实现类。

public class LinkedList
    extends AbstractSequentialList
    implements List, Deque, Cloneable, java.io.Serializable