public class SoftReferenceObjectPool extends BaseObjectPool implements ObjectPool
SoftReference
based
ObjectPool
.Constructor and Description |
---|
SoftReferenceObjectPool()
Deprecated.
to be removed in pool 2.0. Use
SoftReferenceObjectPool(PoolableObjectFactory) . |
SoftReferenceObjectPool(PoolableObjectFactory factory)
Create a
SoftReferenceObjectPool with the specified factory. |
SoftReferenceObjectPool(PoolableObjectFactory factory,
int initSize)
Deprecated.
because this is a SoftReference pool, prefilled idle obejects may be garbage collected before they are used.
To be removed in Pool 2.0.
|
Modifier and Type | Method and Description |
---|---|
void |
addObject()
Create an object, and place it into the pool.
|
Object |
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 |
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(Object obj)
Invalidates an object from the pool.
|
void |
returnObject(Object obj)
Returns an instance to the pool after successful validation and passivation.
|
void |
setFactory(PoolableObjectFactory factory)
Deprecated.
to be removed in pool 2.0
|
assertOpen, isClosed
public SoftReferenceObjectPool()
SoftReferenceObjectPool(PoolableObjectFactory)
.SoftReferenceObjectPool
without a factory.
setFactory
should be called
before any attempts to use the pool are made.
Generally speaking you should prefer the SoftReferenceObjectPool(PoolableObjectFactory)
constructor.public SoftReferenceObjectPool(PoolableObjectFactory factory)
SoftReferenceObjectPool
with the specified factory.factory
- object factory to use.public SoftReferenceObjectPool(PoolableObjectFactory factory, int initSize) throws Exception, IllegalArgumentException
SoftReferenceObjectPool
with the specified factory and initial idle object count.factory
- object factory to use.initSize
- initial size to attempt to prefill the pool.Exception
- when there is a problem prefilling the pool.IllegalArgumentException
- when factory
is null
.public Object borrowObject() throws 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
borrowObject
in class BaseObjectPool
NoSuchElementException
- if a valid object cannot be providedIllegalStateException
- if invoked on a closed
poolException
- if an exception occurs creating a new instancepublic void returnObject(Object obj) throws 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
returnObject
in class BaseObjectPool
obj
- instance to return to the poolException
public void invalidateObject(Object obj) throws 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
invalidateObject
in class BaseObjectPool
obj
- a borrowed
instance to be disposed.Exception
public void addObject() throws 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
addObject
in class BaseObjectPool
IllegalStateException
- if invoked on a closed
poolException
- when the factory
has a problem creating or passivating an object.public int getNumIdle()
getNumIdle
in interface ObjectPool
getNumIdle
in class BaseObjectPool
public int getNumActive()
getNumActive
in interface ObjectPool
getNumActive
in class BaseObjectPool
public void clear()
clear
in interface ObjectPool
clear
in class BaseObjectPool
public void close() throws 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
close
in class BaseObjectPool
Exception
- never - exceptions clearing the pool are swallowedpublic void setFactory(PoolableObjectFactory factory) throws IllegalStateException
factory
this pool uses
to create new instances. Trying to change
the factory
while there are borrowed objects will
throw an IllegalStateException
.setFactory
in interface ObjectPool
setFactory
in class BaseObjectPool
factory
- the PoolableObjectFactory
used to create new instances.IllegalStateException
- when the factory cannot be set at this timepublic PoolableObjectFactory getFactory()
PoolableObjectFactory
used by this pool to create and manage object instances.Copyright © 2023. All rights reserved.