| org.apache.commons.pool.KeyedObjectPool
All known Subclasses: org.apache.commons.pool.BaseKeyedObjectPool, org.apache.commons.pool.impl.StackKeyedObjectPool, org.apache.commons.pool.impl.GenericKeyedObjectPool,
| KeyedObjectPool | | public interface KeyedObjectPool (Code) | | A "keyed" pooling interface.
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
ObjectPool pools ).
See Also: KeyedPoolableObjectFactory
See Also: KeyedObjectPoolFactory
See Also: ObjectPool
author:
Rodney Waldhoff
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
KeyedObjectPool.setFactory factory or other
implementation dependent mechanism, and place it into the pool. | | 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
KeyedObjectPool.borrowObject 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
KeyedPoolableObjectFactory factory I use
to create new instances (optional operation). |
| addObject | | void addObject(Object key) throws Exception(Code) | | Create an object using my
KeyedObjectPool.setFactory 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).
|
| borrowObject | | Object borrowObject(Object key) throws Exception(Code) | | Obtain an instance from my pool
for the specified key.
By contract, clients MUST return
the borrowed object using
KeyedObjectPool.returnObject(java.lang.Object,java.lang.Object) 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 an instance from my pool. |
| close | | void close() throws Exception(Code) | | Close this pool, and free any resources associated with it.
|
| getNumActive | | int getNumActive(Object key) throws UnsupportedOperationException(Code) | | Returns the number of instances
currently borrowed from but not yet returned
to my pool corresponding to the
given key (optional operation).
Throws
UnsupportedOperationException if this information is not available.
Parameters:
key - the key the number of instances corresponding to the given key currently borrowed in my pool
throws:
UnsupportedOperationException - when this implementation doesn't support the operation |
| invalidateObject | | void invalidateObject(Object key, Object obj) throws Exception(Code) | | Invalidates an object from the pool
By contract, obj MUST have been obtained
using
KeyedObjectPool.borrowObject 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.validateObject method should be
used instead.
Parameters:
obj - a KeyedObjectPool.borrowObject borrowed instance to be returned. |
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