Package org.apache.commons.pool2

Class PoolUtils.SynchronizedKeyedPooledObjectFactory<K,V>

java.lang.Object

org.apache.commons.pool2.PoolUtils.SynchronizedKeyedPooledObjectFactory<K,V>

Type Parameters:

K - pooled object factory key type

V - pooled object factory value type

All Implemented Interfaces:

KeyedPooledObjectFactory<K,V>

Enclosing class:

PoolUtils

private static final class PoolUtils.SynchronizedKeyedPooledObjectFactory<K,V>
extends Object
implements KeyedPooledObjectFactory<K,V>

A fully synchronized KeyedPooledObjectFactory that wraps a KeyedPooledObjectFactory 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 KeyedPooledObjectFactory<K,V>	keyedFactory	Wrapped factory
private final ReentrantReadWriteLock.WriteLock	writeLock	Synchronization lock

Constructor Summary

Constructors

Constructor	Description
SynchronizedKeyedPooledObjectFactory(KeyedPooledObjectFactory<K,V> keyedFactory)	Creates a SynchronizedKeyedPooledObjectFactory wrapping the given factory.

Method Summary

Modifier and Type	Method	Description
void	activateObject(K key, PooledObject<V> p)	Reinitializes an instance to be returned by the pool.
void	destroyObject(K key, PooledObject<V> p)	Destroys an instance no longer needed by the pool.
PooledObject<V>	makeObject(K key)	Creates an instance that can be served by the pool and wrap it in a PooledObject to be managed by the pool.
void	passivateObject(K key, PooledObject<V> p)	Uninitializes an instance to be returned to the idle object pool.
String	toString()
boolean	validateObject(K key, PooledObject<V> p)	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

Methods inherited from interface org.apache.commons.pool2.KeyedPooledObjectFactory

destroyObject

Field Details

writeLock

private final ReentrantReadWriteLock.WriteLock writeLock

Synchronization lock

keyedFactory

private final KeyedPooledObjectFactory<K,V> keyedFactory

Wrapped factory

Constructor Details

SynchronizedKeyedPooledObjectFactory

SynchronizedKeyedPooledObjectFactory(KeyedPooledObjectFactory<K,V> keyedFactory)
                              throws IllegalArgumentException

Creates a SynchronizedKeyedPooledObjectFactory wrapping the given factory.

Parameters:

keyedFactory - underlying factory to wrap

Throws:

IllegalArgumentException - if the factory is null

Method Details

activateObject

public void activateObject(K key,
 PooledObject<V> p)
                    throws Exception

Reinitializes an instance to be returned by the pool.

Specified by:

activateObject in interface KeyedPooledObjectFactory<K,V>

Parameters:

key - the key used when selecting the object

p - a PooledObject wrapping the instance to be activated

Throws:

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

See Also:

• KeyedPooledObjectFactory.destroyObject(K, org.apache.commons.pool2.PooledObject<V>)

destroyObject

public void destroyObject(K key,
 PooledObject<V> p)
                   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 KeyedPooledObjectFactory<K,V>

Parameters:

key - the key used when selecting the instance

p - a PooledObject wrapping the instance to be destroyed

Throws:

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

See Also:

• KeyedPooledObjectFactory.validateObject(K, org.apache.commons.pool2.PooledObject<V>)
• KeyedObjectPool.invalidateObject(K, V)

makeObject

public PooledObject<V> makeObject(K key)
                           throws Exception

Creates an instance that can be served by the pool and wrap it in a PooledObject to be managed by the pool.

Specified by:

makeObject in interface KeyedPooledObjectFactory<K,V>

Parameters:

key - the key used when constructing the object

Returns:

a PooledObject wrapping 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.

passivateObject

public void passivateObject(K key,
 PooledObject<V> p)
                     throws Exception

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

Specified by:

passivateObject in interface KeyedPooledObjectFactory<K,V>

Parameters:

key - the key used when selecting the object

p - a PooledObject wrapping the instance to be passivated

Throws:

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

See Also:

• KeyedPooledObjectFactory.destroyObject(K, org.apache.commons.pool2.PooledObject<V>)

toString

public String toString()

Overrides:

toString in class Object

validateObject

public boolean validateObject(K key,
 PooledObject<V> p)

Ensures that the instance is safe to be returned by the pool.

Specified by:

validateObject in interface KeyedPooledObjectFactory<K,V>

Parameters:

key - the key used when selecting the object

p - a PooledObject wrapping the instance to be validated

Returns:

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