org.springframework.aop.target
Class AbstractPoolingTargetSource

java.lang.Object
  org.springframework.aop.target.AbstractPrototypeTargetSource
      org.springframework.aop.target.AbstractPoolingTargetSource

All Implemented Interfaces:

BeanFactoryAware, DisposableBean, InitializingBean, PoolingConfig, TargetSource

Direct Known Subclasses:

CommonsPoolTargetSource

public abstract class AbstractPoolingTargetSource

extends AbstractPrototypeTargetSource

implements PoolingConfig, DisposableBean

Abstract uperclass for pooling TargetSources that maintains a pool of target instances, acquiring and releasing a target object from the pool for each method invocation. This class is independent of pooling technology.

Subclasses must implement the getTarget() and releaseTarget() methods to work with their chosen pool. The newPrototypeInstance() method inherited from AbstractPrototypeTargetSource can be used to create objects to put in the pool. Subclasses must also implement some of the monitoring methods from the PoolingConfig interface. This class provides the getPoolingConfigMixin() method to return an IntroductionAdvisor making these stats available on proxied objects.

This class implements DisposableBean to force subclasses to implement a destroy() method to close down their pool.

Version:

$Id: AbstractPoolingTargetSource.java,v 1.7 2004/03/18 02:46:13 trisberg Exp $

Author:

Rod Johnson

Field Summary

Fields inherited from class org.springframework.aop.target.AbstractPrototypeTargetSource

logger

Constructor Summary

AbstractPoolingTargetSource()

Method Summary

protected abstract void	createPool(BeanFactory beanFactory) Create the pool.
int	getMaxSize() Return the maximum size of the pool.
DefaultIntroductionAdvisor	getPoolingConfigMixin()
abstract java.lang.Object	getTarget() Acquire an object from the pool.
abstract void	releaseTarget(java.lang.Object target) Return the given object to the pool.
void	setBeanFactory(BeanFactory beanFactory) Set the owning BeanFactory.
void	setMaxSize(int maxSize) Set the maximum size of the pool.

Methods inherited from class org.springframework.aop.target.AbstractPrototypeTargetSource

afterPropertiesSet, getTargetBeanName, getTargetClass, isStatic, newPrototypeInstance, setTargetBeanName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.springframework.aop.target.PoolingConfig

getActive, getFree

Methods inherited from interface org.springframework.beans.factory.DisposableBean

destroy

Constructor Detail

AbstractPoolingTargetSource

public AbstractPoolingTargetSource()

Method Detail

setMaxSize

public void setMaxSize(int maxSize)

Set the maximum size of the pool.

Parameters:

maxSize - the size for the pool

getMaxSize

public int getMaxSize()

Return the maximum size of the pool.

Specified by:

getMaxSize in interface PoolingConfig

Returns:

the size of the pool

setBeanFactory

public final void setBeanFactory(BeanFactory beanFactory)
                          throws BeansException

Description copied from class: AbstractPrototypeTargetSource

Set the owning BeanFactory. We need to save a reference so that we can use the getBean() method on every invocation.

Specified by:

setBeanFactory in interface BeanFactoryAware

Overrides:

setBeanFactory in class AbstractPrototypeTargetSource

Throws:

BeansException

createPool

protected abstract void createPool(BeanFactory beanFactory)
                            throws java.lang.Exception

Create the pool.

Parameters:

beanFactory - owning BeanFactory, in case we need collaborators from it (normally our own properties are sufficient)

Throws:

java.lang.Exception - to avoid placing constraints on pooling APIs

getTarget

public abstract java.lang.Object getTarget()
                                    throws java.lang.Exception

Acquire an object from the pool.

Specified by:

getTarget in interface TargetSource

Returns:

an object from the pool

Throws:

java.lang.Exception - we may need to deal with checked exceptions from pool APIs, so we're forgiving with our exception signature, although we don't like APIs that throw Exception

releaseTarget

public abstract void releaseTarget(java.lang.Object target)
                            throws java.lang.Exception

Return the given object to the pool.

Specified by:

releaseTarget in interface TargetSource

Parameters:

target - object that must have been acquired from the pool via a call to acquireTarget()

Throws:

java.lang.Exception - to allow pooling APIs to throw exception

getPoolingConfigMixin

public DefaultIntroductionAdvisor getPoolingConfigMixin()

Returns:

an IntroductionAdvisor that providing a mixin exposing statistics about the pool maintained by this object