org.vibur.objectpool

Interface PoolObjectFactory<T>

Type Parameters:

T - the type of objects held in the client object pool

public interface PoolObjectFactory<T>

Defines the interface that will be implemented by the factory used by the object pools defined in the package, in order to control the lifecycle of the objects in the pools.

Author:

Simeon Malchev

Method Summary

Modifier and Type	Method and Description
T	create() Creates a new object for the calling object pool.
void	destroy(T obj) A method which will be called when an object from the object pool needs to be destroyed, which is when the readyToTake(T) or readyToRestore(T) methods have returned false, or when the pool is shrinking its size (via calling reduceCreatedBy/To), or when the pool is terminating.
boolean	readyToRestore(T obj) A validation/passivation hook which will be called by the restore methods of ConcurrentPool when an object taken before that from the object pool is about to be restored (returned back) to the pool.
boolean	readyToTake(T obj) A validation/activation hook which will be called by the take... methods of ConcurrentPool when an object from the object pool is requested by the application.

Method Detail

create

T create()

Creates a new object for the calling object pool. This object is presumed to be ready (and valid) for immediate use. Should never return null.

This method will be called by the constructors of ConcurrentPool, and by any of its take... methods if they were able to obtain a permit from the counting Semaphore guarding the pool, but there was no ready and valid object in the pool. I.e., this is the case when a new object is created lazily in the pool upon request.

Returns:

a new object for this object pool

readyToTake

boolean readyToTake(T obj)

A validation/activation hook which will be called by the take... methods of ConcurrentPool when an object from the object pool is requested by the application. This is an optional operation which concrete implementation may simply always return true.

If there is a particular activation or validation which needs to be done for the taken from the pool object, this is the ideal place where it can be done.

Parameters:

obj - an object which is taken from the object pool and which is to be given to the calling application

Returns:

true if the validation/activation is successful, false otherwise

See Also:

readyToRestore(T)

readyToRestore

boolean readyToRestore(T obj)

A validation/passivation hook which will be called by the restore methods of ConcurrentPool when an object taken before that from the object pool is about to be restored (returned back) to the pool. This is an optional operation which concrete implementation may simply always return true.

If there is a particular passivation or validation which needs to be done for the restored to the pool object, this is the ideal place where it can be done.

Parameters:

obj - an object which has been taken before that from this object pool and which is now to be restored to the pool

Returns:

true if the validation/passivation is successful, false otherwise

See Also:

readyToTake(T)

destroy

void destroy(T obj)

A method which will be called when an object from the object pool needs to be destroyed, which is when the readyToTake(T) or readyToRestore(T) methods have returned false, or when the pool is shrinking its size (via calling reduceCreatedBy/To), or when the pool is terminating. The simplest implementation of this method may simply do nothing, however if there are any allocated resources associated with the to-be-destroyed object, like network connections or similar, this is the ideal place where they can be de-allocated.

Parameters:

obj - an object from the pool which needs to be destroyed