org.apache.commons.pool
public interface KeyedObjectPool
A keyed pool pools instances of multiple types. Each type may be accessed using an arbitrary key.
Example of use:
Object obj = null; Object key = "Key"; try { obj = pool.borrowObject(key); //...use the object... } catch(Exception e) { //...handle any exceptions... } finally { // make sure the object is returned to the pool if(null != obj) { pool.returnObject(key,obj); } } |
KeyedObjectPool implementations may choose to store at most
one instance per key value, or may choose to maintain a pool of instances
for each key (essentially creating a java.util.Map Map
of
pools
).
Version: $Revision: 155430 $ $Date: 2005-02-26 08:13:28 -0500 (Sat, 26 Feb 2005) $
Method Summary | |
---|---|
void | addObject(Object key)
Create an object using my factory or other
implementation dependent mechanism, and place it into the pool.
addObject() is useful for "pre-loading" a pool with idle objects.
|
Object | borrowObject(Object key)
Obtain an instance from my pool
for the specified key.
|
void | clear()
Clears my pool, removing all pooled instances
(optional operation).
|
void | clear(Object key)
Clears the specified pool, removing all
pooled instances corresponding to
the given key (optional operation).
|
void | close()
Close this pool, and free any resources associated with it. |
int | getNumActive(Object key)
Returns the number of instances
currently borrowed from but not yet returned
to my pool corresponding to the
given key (optional operation).
|
int | getNumActive()
Returns the total number of instances
current borrowed from my pool but not
yet returned (optional operation).
|
int | getNumIdle(Object key)
Returns the number of instances
corresponding to the given key
currently idle in my pool (optional operation).
|
int | getNumIdle()
Returns the total number of instances
currently idle in my pool (optional operation).
|
void | invalidateObject(Object key, Object obj)
Invalidates an object from the pool
By contract, obj MUST have been obtained
using borrowObject
or a related method as defined in an implementation
or sub-interface
using a key that is equivalent to the one used to
borrow the Object in the first place.
|
void | returnObject(Object key, Object obj)
Return an instance to my pool.
|
void | setFactory(KeyedPoolableObjectFactory factory)
Sets the factory I use
to create new instances (optional operation). |
factory
or other
implementation dependent mechanism, and place it into the pool.
addObject() is useful for "pre-loading" a pool with idle objects.
(Optional operation). returnObject
,
or a related method as defined in an implementation
or sub-interface,
using a key that is equivalent to the one used to
borrow the instance in the first place.
Parameters: key the key used to obtain the object
Returns: an instance from my pool.
Throws: UnsupportedOperationException when this implementation doesn't support the operation
Parameters: key the key to clear
Throws: UnsupportedOperationException when this implementation doesn't support the operation
Parameters: key the key
Returns: the number of instances corresponding to the given key currently borrowed in my pool
Throws: UnsupportedOperationException when this implementation doesn't support the operation
Returns: the total number of instances currently borrowed from my pool
Throws: UnsupportedOperationException when this implementation doesn't support the operation
Parameters: key the key
Returns: the number of instances corresponding to the given key currently idle in my pool
Throws: UnsupportedOperationException when this implementation doesn't support the operation
Returns: the total number of instances currently idle in my pool
Throws: UnsupportedOperationException when this implementation doesn't support the operation
borrowObject
or a related method as defined in an implementation
or sub-interface
using a key that is equivalent to the one used to
borrow the Object in the first place.
This method should be used when an object that has been borrowed is determined (due to an exception or other problem) to be invalid. If the connection should be validated before or after borrowing, then the PoolableObjectFactory method should be used instead.
Parameters: obj a borrowed
instance to be returned.
borrowObject
or a related method as defined in an implementation
or sub-interface
using a key that is equivalent to the one used to
borrow the Object in the first place.
Parameters: key the key used to obtain the object obj a borrowed
instance to be returned.
factory
I use
to create new instances (optional operation).Parameters: factory the KeyedPoolableObjectFactory I use to create new instances.
Throws: IllegalStateException when the factory cannot be set at this time UnsupportedOperationException when this implementation doesn't support the operation