Package edu.uiuc.ncsa.security.core.util

Class Pool<T>

java.lang.Object

edu.uiuc.ncsa.security.core.util.Pool<T>

Direct Known Subclasses:

ConnectionPool

public abstract class Pool<T>
extends Object

A pool of items, that is to say, a managed list that keeps valid items on it and can create or destroy them as needed. when pushing and popping off a stack.

Supremely useful with SQL connections. This does check for validity as a matter of course.

Created by Jeff Gaynor
on Mar 12, 2010 at 3:48:20 PM

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	DEEP_DEBUG	Set true if you want to see a ton of low level debugging for this.
static int	INFINITE
protected int	inUse
protected int	maxSize
protected Queue<T>	stack
protected int	totalCreated
protected int	totalDestroyed

Constructor Summary

Constructors

Constructor	Description
Pool()

Method Summary

Modifier and Type	Method	Description
abstract T	create()	Create a new, ready-to-use object for the pool
abstract void	destroy(T object)	Destroy an object that is no longer needed.
T	doCreate()
void	doDestroy(T item)	Destroying an item reduces the number of in-use items.
int	getMaxSize()	Get the maximum number of items
Queue<T>	getStack()
boolean	isValid(T object)	Is this item still good? If not it will be removed from the pool so a new one can be created.
T	pop()	Pop an object off the stack if there is one, otherwise, create one.
void	push(T object)	Check an object into the pool.
void	setMaxSize(int c)	Set the maximum number of items.
String	toString()
protected void	trace(String x)

Methods inherited from class java.lang.Object

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

Field Detail

INFINITE

public static final int INFINITE

See Also:

Constant Field Values

maxSize

protected int maxSize

totalCreated

protected int totalCreated

totalDestroyed

protected int totalDestroyed

inUse

protected int inUse

DEEP_DEBUG

protected boolean DEEP_DEBUG

Set true if you want to see a ton of low level debugging for this.

stack

protected Queue<T> stack

Constructor Detail

Pool

public Pool()

Method Detail

trace

protected void trace(String x)

getStack

public Queue<T> getStack()

create

public abstract T create()
                  throws PoolException

Create a new, ready-to-use object for the pool

Returns:

the object

Throws:

PoolException

destroy

public abstract void destroy(T object)
                      throws PoolException

Destroy an object that is no longer needed.

Parameters:

object - the object

Throws:

PoolException

isValid

public boolean isValid(T object)
                throws PoolException

Is this item still good? If not it will be removed from the pool so a new one can be created. Default is to return true.

Throws:

PoolException

pop

public T pop()
      throws PoolException

Pop an object off the stack if there is one, otherwise, create one.

Returns:

the object

Throws:

PoolException

doCreate

public T doCreate()
           throws PoolException

Throws:

PoolException

doDestroy

public void doDestroy(T item)
               throws PoolException

Destroying an item reduces the number of in-use items. Do not call this on an item that hasn't been checked out.

Parameters:

item - the item

Throws:

PoolException

setMaxSize

public void setMaxSize(int c)

Set the maximum number of items.

Parameters:

c -

getMaxSize

public int getMaxSize()

Get the maximum number of items

Returns:

capacity

push

public void push(T object)
          throws PoolException

Check an object into the pool. If the pool is at capacity, destroy the object.

Parameters:

object - the object

Throws:

PoolException

toString

public String toString()

Overrides:

toString in class Object