T
- the type of objects held in this poolpublic class SoftReferenceObjectPool<T> extends BaseObjectPool<T> implements ObjectPool<T>
SoftReference
based
ObjectPool
.Constructor and Description |
---|
SoftReferenceObjectPool(PoolableObjectFactory<T> factory)
Create a
SoftReferenceObjectPool with the specified factory. |
Modifier and Type | Method and Description |
---|---|
void |
addObject()
Create an object, and place it into the pool.
|
T |
borrowObject()
Borrow an object from the pool.
|
void |
clear()
Clears any objects sitting idle in the pool.
|
void |
close()
Close this pool, and free any resources associated with it.
|
PoolableObjectFactory<T> |
getFactory()
Returns the
PoolableObjectFactory used by this pool to create and manage object instances. |
int |
getNumActive()
Return the number of instances currently borrowed from this pool.
|
int |
getNumIdle()
Returns an approximation not less than the of the number of idle instances in the pool.
|
void |
invalidateObject(T obj)
Invalidates an object from the pool.
|
void |
returnObject(T obj)
Returns an instance to the pool after successful validation and passivation.
|
isClosed
public SoftReferenceObjectPool(PoolableObjectFactory<T> factory)
SoftReferenceObjectPool
with the specified factory.factory
- object factory to use.public void addObject() throws java.lang.Exception
Create an object, and place it into the pool. addObject() is useful for "pre-loading" a pool with idle objects.
Before being added to the pool, the newly created instance is
validated
and
passivated
. If validation
fails, the new instance is destroyed
.
Exceptions generated by the factory makeObject
or passivate
are
propagated to the caller. Exceptions destroying instances are silently swallowed.
addObject
in interface ObjectPool<T>
addObject
in class BaseObjectPool<T>
java.lang.IllegalStateException
- if invoked on a closed
pooljava.lang.Exception
- when the factory
has a problem creating or passivating an object.public T borrowObject() throws java.lang.Exception
Borrow an object from the pool. If there are no idle instances available in the pool, the configured
factory's PoolableObjectFactory.makeObject()
method is invoked to create a new instance.
All instances are activated
and
validated
before being returned by this
method. If validation fails or an exception occurs activating or validating an idle instance,
the failing instance is destroyed
and another
instance is retrieved from the pool, validated and activated. This process continues until either the
pool is empty or an instance passes validation. If the pool is empty on activation or
it does not contain any valid instances, the factory's makeObject
method is used
to create a new instance. If the created instance either raises an exception on activation or
fails validation, NoSuchElementException
is thrown. Exceptions thrown by MakeObject
are propagated to the caller; but other than ThreadDeath
or VirtualMachineError
,
exceptions generated by activation, validation or destroy methods are swallowed silently.
borrowObject
in interface ObjectPool<T>
borrowObject
in class BaseObjectPool<T>
java.util.NoSuchElementException
- if a valid object cannot be providedjava.lang.IllegalStateException
- if invoked on a closed
pooljava.lang.Exception
- if an exception occurs creating a new instancepublic void clear()
clear
in interface ObjectPool<T>
clear
in class BaseObjectPool<T>
public void close() throws java.lang.Exception
Close this pool, and free any resources associated with it. Invokes
clear()
to destroy and remove instances in the pool.
Calling addObject()
or borrowObject()
after invoking
this method on a pool will cause them to throw an
IllegalStateException
.
close
in interface ObjectPool<T>
close
in class BaseObjectPool<T>
java.lang.Exception
- never - exceptions clearing the pool are swallowedpublic PoolableObjectFactory<T> getFactory()
PoolableObjectFactory
used by this pool to create and manage object instances.public int getNumActive()
getNumActive
in interface ObjectPool<T>
getNumActive
in class BaseObjectPool<T>
public int getNumIdle()
getNumIdle
in interface ObjectPool<T>
getNumIdle
in class BaseObjectPool<T>
public void invalidateObject(T obj) throws java.lang.Exception
Invalidates an object from the pool.
By contract, obj
must have been obtained
using borrowObject
.
This method should be used when an object that has been borrowed is determined (due to an exception or other problem) to be invalid.
invalidateObject
in interface ObjectPool<T>
invalidateObject
in class BaseObjectPool<T>
obj
- a borrowed
instance to be disposed.java.lang.Exception
public void returnObject(T obj) throws java.lang.Exception
Returns an instance to the pool after successful validation and passivation. The returning instance is destroyed if any of the following are true:
validation
failspassivation
throws an exceptionExceptions passivating or destroying instances are silently swallowed. Exceptions validating instances are propagated to the client.
returnObject
in interface ObjectPool<T>
returnObject
in class BaseObjectPool<T>
obj
- instance to return to the pooljava.lang.Exception
Copyright © 2001-2012 Apache Software Foundation. Documenation generated July 25 2016.