Package org.apache.commons.pool

Class PoolUtils.SynchronizedPoolableObjectFactory<T>

java.lang.Object

org.apache.commons.pool.PoolUtils.SynchronizedPoolableObjectFactory<T>

All Implemented Interfaces:

PoolableObjectFactory<T>

Enclosing class:

PoolUtils

private static class PoolUtils.SynchronizedPoolableObjectFactory<T>
extends Object
implements PoolableObjectFactory<T>

A fully synchronized PoolableObjectFactory that wraps a PoolableObjectFactory and synchronizes access to the wrapped factory methods.

Note: This should not be used on pool implementations that already provide proper synchronization such as the pools provided in the Commons Pool library.

Field Summary

Fields

Modifier and Type	Field	Description
private final PoolableObjectFactory<T>	factory	Wrapped factory
private final Object	lock	Synchronization lock

Constructor Summary

Constructors

Constructor	Description
SynchronizedPoolableObjectFactory(PoolableObjectFactory<T> factory)	Create a SynchronizedPoolableObjectFactory wrapping the given factory.

Method Summary

Modifier and Type	Method	Description
void	activateObject(T obj)	Reinitialize an instance to be returned by the pool.
void	destroyObject(T obj)	Destroys an instance no longer needed by the pool.
T	makeObject()	Creates an instance that can be served by the pool.
void	passivateObject(T obj)	Uninitialize an instance to be returned to the idle object pool.
String	toString()
boolean	validateObject(T obj)	Ensures that the instance is safe to be returned by the pool.

Methods inherited from class java.lang.Object

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

Field Details

lock

private final Object lock

Synchronization lock

factory

private final PoolableObjectFactory<T> factory

Wrapped factory

Constructor Details

SynchronizedPoolableObjectFactory

SynchronizedPoolableObjectFactory(PoolableObjectFactory<T> factory)
                           throws IllegalArgumentException

Create a SynchronizedPoolableObjectFactory wrapping the given factory.

Parameters:

factory - underlying factory to wrap

Throws:

IllegalArgumentException - if the factory is null

Method Details

makeObject

public T 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.

Specified by:

makeObject in interface PoolableObjectFactory<T>

Returns:

an instance that can be served by the pool.

Throws:

Exception - if there is a problem creating a new instance, this will be propagated to the code requesting an object.

destroyObject

public void destroyObject(T 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.

Specified by:

destroyObject in interface PoolableObjectFactory<T>

Parameters:

obj - the instance to be destroyed

Throws:

Exception - should be avoided as it may be swallowed by the pool implementation.

See Also:

• PoolableObjectFactory.validateObject(T)
• ObjectPool.invalidateObject(T)

validateObject

public boolean validateObject(T obj)

Ensures that the instance is safe to be returned by the pool. Returns false if obj should be destroyed.

Specified by:

validateObject in interface PoolableObjectFactory<T>

Parameters:

obj - the instance to be validated

Returns:

false if obj is not valid and should be dropped from the pool, true otherwise.

activateObject

public void activateObject(T obj)
                    throws Exception

Reinitialize an instance to be returned by the pool.

Specified by:

activateObject in interface PoolableObjectFactory<T>

Parameters:

obj - the instance to be activated

Throws:

Exception - if there is a problem activating obj, this exception may be swallowed by the pool.

See Also:

• PoolableObjectFactory.destroyObject(T)

passivateObject

public void passivateObject(T obj)
                     throws Exception

Uninitialize an instance to be returned to the idle object pool.

Specified by:

passivateObject in interface PoolableObjectFactory<T>

Parameters:

obj - the instance to be passivated

Throws:

Exception - if there is a problem passivating obj, this exception may be swallowed by the pool.

See Also:

• PoolableObjectFactory.destroyObject(T)

toString

public String toString()

Overrides:

toString in class Object