Package org.apache.commons.pool
Interface KeyedPoolableObjectFactory<K,V>
-
- Type Parameters:
K- the type of keys in this poolV- the type of objects held in this pool
- All Known Implementing Classes:
BaseKeyedPoolableObjectFactory
public interface KeyedPoolableObjectFactory<K,V>An interface defining life-cycle methods for instances to be served by aKeyedObjectPool.By contract, when an
KeyedObjectPooldelegates to aKeyedPoolableObjectFactory,-
makeObjectis called whenever a new instance is needed. -
activateObjectis invoked on every instance that has beenpassivatedbefore it isborrowedfrom the pool. -
validateObjectis invoked onactivatedinstances to make sure they can beborrowedfrom the pool.validateObjectmay also be used to test an instance beingreturnedto the pool before it ispassivated. It will only be invoked on an activated instance. -
passivateObjectis invoked on every instance when it is returned to the pool. -
destroyObjectis invoked on every instance when it is being "dropped" from the pool (whether due to the response fromvalidateObject, 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.
KeyedPoolableObjectFactorymust be thread-safe. The only promise anKeyedObjectPoolmakes is that the same instance of an object will not be passed to more than one method of aKeyedPoolableObjectFactoryat a time.- Since:
- Pool 1.0
- Version:
- $Revision: 1222388 $ $Date: 2011-12-22 13:28:27 -0500 (Thu, 22 Dec 2011) $
- Author:
- Rodney Waldhoff, Sandy McArthur
- See Also:
KeyedObjectPool
-
-
Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description voidactivateObject(K key, V obj)Reinitialize an instance to be returned by the pool.voiddestroyObject(K key, V obj)Destroy an instance no longer needed by the pool.VmakeObject(K key)Create an instance that can be served by the pool.voidpassivateObject(K key, V obj)Uninitialize an instance to be returned to the idle object pool.booleanvalidateObject(K key, V obj)Ensures that the instance is safe to be returned by the pool.
-
-
-
Method Detail
-
makeObject
V makeObject(K key) throws java.lang.Exception
Create an instance that can be served by the pool.- Parameters:
key- the key used when constructing the object- Returns:
- an instance that can be served by the pool.
- Throws:
java.lang.Exception- if there is a problem creating a new instance, this will be propagated to the code requesting an object.
-
destroyObject
void destroyObject(K key, V obj) throws java.lang.Exception
Destroy 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
objwill 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.
- Parameters:
key- the key used when selecting the instanceobj- the instance to be destroyed- Throws:
java.lang.Exception- should be avoided as it may be swallowed by the pool implementation.- See Also:
validateObject(K, V),KeyedObjectPool.invalidateObject(K, V)
-
validateObject
boolean validateObject(K key, V obj)
Ensures that the instance is safe to be returned by the pool. Returnsfalseifobjshould be destroyed.- Parameters:
key- the key used when selecting the objectobj- the instance to be validated- Returns:
falseifobjis not valid and should be dropped from the pool,trueotherwise.
-
activateObject
void activateObject(K key, V obj) throws java.lang.Exception
Reinitialize an instance to be returned by the pool.- Parameters:
key- the key used when selecting the objectobj- the instance to be activated- Throws:
java.lang.Exception- if there is a problem activatingobj, this exception may be swallowed by the pool.- See Also:
destroyObject(K, V)
-
passivateObject
void passivateObject(K key, V obj) throws java.lang.Exception
Uninitialize an instance to be returned to the idle object pool.- Parameters:
key- the key used when selecting the objectobj- the instance to be passivated- Throws:
java.lang.Exception- if there is a problem passivatingobj, this exception may be swallowed by the pool.- See Also:
destroyObject(K, V)
-
-