Package org.apache.tomcat.util.digester

Class ArrayStack<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractList<E>
java.util.ArrayList<E>
org.apache.tomcat.util.digester.ArrayStack<E>
Type Parameters:
E - Type of object in this stack
All Implemented Interfaces:
Serializable, Cloneable, Iterable<E>, Collection<E>, List<E>, RandomAccess
public class ArrayStack<E> extends ArrayList<E>

Imported copy of the ArrayStack class from Commons Collections, which was the only direct dependency from Digester.

WARNING - This class is public solely to allow it to be used from subpackages of org.apache.commons.digester. It should not be considered part of the public API of Commons Digester. If you want to use such a class yourself, you should use the one from Commons Collections directly.

An implementation of the Stack API that is based on an ArrayList instead of a Vector, so it is not synchronized to protect against multi-threaded access. The implementation is therefore operates faster in environments where you do not need to worry about multiple thread contention.

Unlike Stack, ArrayStack accepts null entries.

Since:
Digester 1.6 (from Commons Collections 1.0)
See Also:

  • Constructor Details

    • ArrayStack

      public ArrayStack()
      Constructs a new empty ArrayStack. The initial size is controlled by ArrayList and is currently 10.

    • ArrayStack

      public ArrayStack(int initialSize)
      Constructs a new empty ArrayStack with an initial size.
      Parameters:
      initialSize - the initial size to use
      Throws:
      IllegalArgumentException - if the specified initial size is negative

  • Method Details

    • empty

      public boolean empty()
      Return true if this stack is currently empty.

      This method exists for compatibility with java.util.Stack. New users of this class should use isEmpty instead.

      Returns:
      true if the stack is currently empty

    • peek

      public E peek() throws EmptyStackException
      Returns the top item off of this stack without removing it.
      Returns:
      the top item on the stack
      Throws:
      EmptyStackException - if the stack is empty

    • peek

      public E peek(int n) throws EmptyStackException
      Returns the n'th item down (zero-relative) from the top of this stack without removing it.
      Parameters:
      n - the number of items down to go
      Returns:
      the n'th item on the stack, zero relative
      Throws:
      EmptyStackException - if there are not enough items on the stack to satisfy this request

    • pop

      public E pop() throws EmptyStackException
      Pops the top item off of this stack and return it.
      Returns:
      the top item on the stack
      Throws:
      EmptyStackException - if the stack is empty

    • push

      public E push(E item)
      Pushes a new item onto the top of this stack. The pushed item is also returned. This is equivalent to calling add.
      Parameters:
      item - the item to be added
      Returns:
      the item just pushed