K - the type of keys in this poolV - the type of objects held in this poolpublic interface KeyedPoolableObjectFactory<K,V>
KeyedObjectPool.
By contract, when an KeyedObjectPool
delegates to a KeyedPoolableObjectFactory,
makeObject
is called whenever a new instance is needed.
activateObject
is invoked on every instance that has been
passivated before it is
borrowed from the pool.
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.
passivateObject
is invoked on every instance when it is returned to the pool.
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.
KeyedPoolableObjectFactory must be thread-safe. The only promise
an KeyedObjectPool makes is that the same instance of an object will not
be passed to more than one method of a KeyedPoolableObjectFactory
at a time.
KeyedObjectPool| Modifier and Type | Method and Description |
|---|---|
void |
activateObject(K key,
V obj)
Reinitialize an instance to be returned by the pool.
|
void |
destroyObject(K key,
V obj)
Destroy an instance no longer needed by the pool.
|
V |
makeObject(K key)
Create an instance that can be served by the pool.
|
void |
passivateObject(K key,
V obj)
Uninitialize an instance to be returned to the idle object pool.
|
boolean |
validateObject(K key,
V obj)
Ensures that the instance is safe to be returned by the pool.
|
V makeObject(K key) throws Exception
key - the key used when constructing the objectException - if there is a problem creating a new instance,
this will be propagated to the code requesting an object.void destroyObject(K key, V obj) throws Exception
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.
key - the key used when selecting the instanceobj - the instance to be destroyedException - should be avoided as it may be swallowed by
the pool implementation.validateObject(K, V),
KeyedObjectPool.invalidateObject(K, V)boolean validateObject(K key, V obj)
false if obj should be destroyed.key - the key used when selecting the objectobj - the instance to be validatedfalse if obj is not valid and should
be dropped from the pool, true otherwise.void activateObject(K key, V obj) throws Exception
key - the key used when selecting the objectobj - the instance to be activatedException - if there is a problem activating obj,
this exception may be swallowed by the pool.destroyObject(K, V)void passivateObject(K key, V obj) throws Exception
key - the key used when selecting the objectobj - the instance to be passivatedException - if there is a problem passivating obj,
this exception may be swallowed by the pool.destroyObject(K, V)Copyright © 2000-2021 Apache Software Foundation. All Rights Reserved.