All Known Implementing Classes:
    BasePoolableObjectFactory, LargePoolableObjectFactory, SimpleFactory, PoolableObjectFactoryAdaptor, SimpleFactory, SmallPoolableObjectFactory, SleepingObjectFactory, SynchronizedPoolableObjectFactory

By contract, when an ObjectPool delegates to a PoolableObjectFactory ,

1. makeObject is called whenever a new instance is needed.
2. activateObject is invoked on every instance that has been passivated before it is borrowed from the pool.
3. validateObject is invoked on activated instances to make sure they can be borrowed from the pool. validateObject may also be used to test an instance being returned to the pool before it is passivated . It will only be invoked on an activated instance.
4. passivateObject is invoked on every instance when it is returned to the pool.
5. destroyObject is invoked on every instance when it is being "dropped" from the pool (whether due to the response from validateObject, or for reasons specific to the pool implementation.) There is no guarantee that the instance being destroyed will be considered active, passive or in a generally consistent state.

PoolableObjectFactory must be thread-safe. The only promise an ObjectPool makes is that the same instance of an object will not be passed to more than one method of a PoolableObjectFactory at a time.

Also see:

ObjectPool
author: Rodney - Waldhoff

author: Sandy - McArthur

version: $ - Revision: 480413 $ $Date: 2006-11-28 22:16:05 -0700 (Tue, 28 Nov 2006) $

since: Pool - 1.0

 public  void activateObject(Object obj) throws Exception
Reinitialize an instance to be returned by the pool.

 public  void destroyObject(Object obj) throws Exception
Destroys an instance no longer needed by the pool.

It is important for implementations of this method to be aware
that there is no guarantee about what state obj
will be in and the implementation should be prepared to handle
unexpected errors.


Also, an implementation must take in to consideration that
instances lost to the garbage collector may never be destroyed.

 public Object makeObject() throws Exception
Creates an instance that can be served by the pool.
Instances returned from this method should be in the
same state as if they had been
 activated . They will not be
activated before being served by the pool.

 public  void passivateObject(Object obj) throws Exception
Uninitialize an instance to be returned to the idle object pool.

 public boolean validateObject(Object obj)
Ensures that the instance is safe to be returned by the pool.
Returns false if obj should be destroyed.