ArrayList | +--org.apache.commons.collections.ArrayStackAll Implemented Interfaces:
java.util.Stack
Constructs a new empty ArrayStack. |
ArrayStack(int initialSize) Constructs a new empty ArrayStack with an initial size. |
boolean | empty() Return true if this stack is currently empty. |
Object | get() Returns the element on the top of the stack. |
Object | peek() Returns the top item off of this stack without removing it. |
Object | peek(int n) Returns the n'th item down (zero-relative) from the top of this stack without removing it. |
Object | pop() Pops the top item off of this stack and return it. |
Object | push(Object item) Pushes a new item onto the top of this stack. |
Object | remove() Removes the element on the top of the stack. |
int | search(Object object) Returns the one-based position of the distance from the top that the specified object exists on this stack, where the top-most element is considered to be at distance 1. |
public ArrayStack()
ArrayStack
. The initial size
is controlled by ArrayList
and is currently 10.
public ArrayStack(int initialSize)
ArrayStack
with an initial size.
- if the specified initial size
is negativepublic boolean empty()
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.
public Object get()
BufferUnderflowException
- if the stack is emptypublic Object peek()
- if the stack is emptypublic Object peek(int n)
- if there are not enough items on the
stack to satisfy this requestpublic Object pop()
- if the stack is emptypublic Object push(Object item)
add
.
public Object remove()
BufferUnderflowException
- if the stack is emptypublic int search(Object object)
1
. If the object is not
present on the stack, return -1
instead. The
equals()
method is used to compare to the items
in this stack.
ArrayList
instead of aVector
, 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. The removal order of anArrayStack
is based on insertion order: The most recently added element is removed first. The iteration order is not the same as the removal order. The iterator returns elements from the bottom up, whereas the remove() method removes them from the top down. UnlikeStack
,ArrayStack
accepts null entries.