com.sapportals.portal.prt.util
Class AbstractPool

java.lang.Object
  |
  +--com.sapportals.portal.prt.util.AbstractPool

Direct Known Subclasses:

StringBufferPool

public abstract class AbstractPool

extends java.lang.Object

Manages a pool of objects. Unused objects are removed after a certain period of time. The maximum number of objects managed by the pool is by default 100.
This property can be overriden when constructing the pool

Version:

$Revision: #3 $
$File:$ , $Revision:$ Last modified on $Date:$ by $Author:$ using $Change:$ Copyright (c) SAP Portals Europe GmbH 2001

Field Summary

protected int	mm_maxPoolSize
protected java.util.List	mm_unlocked Contains pool objects that are available for use

Constructor Summary

AbstractPool(int initialCapacity)
Construct a pool given an initial capacity and the maximum number set to 100 to manage

AbstractPool(int initialCapacity, int nbInitialInstance)
Construct a pool given an initial capacity and the number of initial items to manage

AbstractPool(int initialCapacity, int nbInitialInstance, int maxNumberObjects)
Construct a pool given an initial capacity and the maximum number of items to manage

Method Summary

protected abstract java.lang.Object	createPoolObject() Factory method to create pool objects
protected abstract void	expirePoolObject(java.lang.Object o) Callback when object are not managed anymore by the pool.
java.lang.Object	getPoolObject() Returns an object from the pool. If no object was available, the object factory is called to instantiate an object
void	releasePoolObject(java.lang.Object o) Tells the pool to release an object and make it available in the pool.
protected abstract boolean	validatePoolObject(java.lang.Object o) Method called to validate an object that has been put back in the pool

Methods inherited from class java.lang.Object

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

Field Detail

mm_maxPoolSize

protected int mm_maxPoolSize

mm_unlocked

protected java.util.List mm_unlocked

Contains pool objects that are available for use

Constructor Detail

AbstractPool

public AbstractPool(int initialCapacity)

Construct a pool given an initial capacity and the maximum number set to 100 to manage

Parameters:

initialCapacity - the initial container capacity

AbstractPool

public AbstractPool(int initialCapacity,
                    int nbInitialInstance)

Construct a pool given an initial capacity and the number of initial items to manage

Parameters:

initialCapacity - the initial container capacity. You should here choose a value that is as close as the given maxNumberObjects.

nbInitialInstance - the initial number of objects to manage in the pool

AbstractPool

public AbstractPool(int initialCapacity,
                    int nbInitialInstance,
                    int maxNumberObjects)

Construct a pool given an initial capacity and the maximum number of items to manage

Parameters:

initialCapacity - the initial container capacity. You should here choose a value that is as close as the given maxNumberObjects.

nbInitialInstance - the initial number of objects to manage in the pool

maxNumberObjects - the maximum number of objects to manage in the pool. value -1 means infinite.

Method Detail

createPoolObject

protected abstract java.lang.Object createPoolObject()
                                              throws java.lang.Exception

Factory method to create pool objects

Returns:

the object to be pooled

Throws:

java.lang.Exception -

validatePoolObject

protected abstract boolean validatePoolObject(java.lang.Object o)

Method called to validate an object that has been put back in the pool

Parameters:

o - the object to validate

Returns:

true is the object is valid for reuse.

expirePoolObject

protected abstract void expirePoolObject(java.lang.Object o)

Callback when object are not managed anymore by the pool.

Parameters:

o - the object that is to be expired

getPoolObject

public java.lang.Object getPoolObject()
                               throws java.lang.Exception

Returns an object from the pool.
If no object was available, the object factory is called to instantiate an object

Returns:

an object coming form the pool, either newly created or and old valid one.

Throws:

java.lang.Exception -

releasePoolObject

public void releasePoolObject(java.lang.Object o)

Tells the pool to release an object and make it available in the pool. If the maximum number of pool objects is reached, the object is not managed anymore by the pool.

Parameters:

o - the object to release.