org.apache.tapestry5.ioc.util
Class Stack<E>

java.lang.Object
  org.apache.tapestry5.ioc.util.Stack<E>

Type Parameters:

E - the type of elements stored in the map

public class Stack<E>
extends Object

A simple, streamlined implementation of Stack. The implementation is not threadsafe.

See Also:

CollectionFactory.newStack()

Constructor Summary

Stack()
Normal constructor supporting an initial size of 20.

Stack(int initialSize)

Method Summary

void	clear() Clears the stack, the same as popping off all elements.
int	getDepth() Returns the number of items currently in the stack.
Object[]	getSnapshot() Returns a snapshot of the current state of the stack as an array of objects.
boolean	isEmpty() Returns true if the stack is empty.
E	peek() Returns the top element of the stack without affecting the stack.
E	pop() Pops the top element off the stack and returns it.
void	push(E item) Pushes a new item onto the stack.
String	toString() Describes the stack, listing the element in order of depth (top element first).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Stack

public Stack()

Normal constructor supporting an initial size of 20.

Stack

public Stack(int initialSize)

Parameters:

initialSize - the initial size of the internal array (which will be expanded as necessary). For best efficiency, set this to the maximum depth of the stack.

Method Detail

isEmpty

public boolean isEmpty()

Returns true if the stack is empty.

getDepth

public int getDepth()

Returns the number of items currently in the stack.

clear

public void clear()

Clears the stack, the same as popping off all elements.

push

public void push(E item)

Pushes a new item onto the stack.

pop

public E pop()

Pops the top element off the stack and returns it.

Returns:

the top element of the stack

Throws:

IllegalStateException - if the stack is empty

peek

public E peek()

Returns the top element of the stack without affecting the stack.

Returns:

top element on the stack

Throws:

IllegalStateException - if the stack is empty

toString

public String toString()

Describes the stack, listing the element in order of depth (top element first).

Overrides:

toString in class Object

Returns:

string description of the stack

getSnapshot

public Object[] getSnapshot()

Returns a snapshot of the current state of the stack as an array of objects. The first object is the deepest in the stack, the last object is the most shallowest (most recently pushed onto the stack). The returned array may be manipulated (it is a copy).

Returns:

the stack as an object array