Class AbstractPoolingTargetSource

All Implemented Interfaces:
Serializable, PoolingConfig, TargetClassAware, TargetSource, Aware, BeanFactoryAware, DisposableBean
Direct Known Subclasses:
CommonsPool2TargetSource

public abstract class AbstractPoolingTargetSource extends AbstractPrototypeBasedTargetSource implements PoolingConfig, DisposableBean
Abstract base class for pooling TargetSource implementations which maintain a pool of target instances, acquiring and releasing a target object from the pool for each method invocation. This abstract base class is independent of concrete pooling technology; see the subclass CommonsPool2TargetSource for a concrete example.

Subclasses must implement the getTarget() and releaseTarget(java.lang.Object) methods based on their chosen object pool. The AbstractPrototypeBasedTargetSource.newPrototypeInstance() method inherited from AbstractPrototypeBasedTargetSource can be used to create objects in order to put them into the pool.

Subclasses must also implement some monitoring methods from the PoolingConfig interface. The getPoolingConfigMixin() method makes these stats available on proxied objects through an IntroductionAdvisor.

This class implements the DisposableBean interface in order to force subclasses to implement a DisposableBean.destroy() method, closing down their object pool.

Author:
Rod Johnson, Juergen Hoeller
See Also:
  • Constructor Details

    • AbstractPoolingTargetSource

      public AbstractPoolingTargetSource()
  • Method Details

    • setMaxSize

      public void setMaxSize(int maxSize)
      Set the maximum size of the pool. Default is -1, indicating no size limit.
    • getMaxSize

      public int getMaxSize()
      Return the maximum size of the pool.
      Specified by:
      getMaxSize in interface PoolingConfig
    • setBeanFactory

      public final void setBeanFactory(BeanFactory beanFactory) throws BeansException
      Description copied from class: AbstractBeanFactoryBasedTargetSource
      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 AbstractPrototypeBasedTargetSource
      Parameters:
      beanFactory - owning BeanFactory (never null). The bean can immediately call methods on the factory.
      Throws:
      BeansException - in case of initialization errors
      See Also:
    • createPool

      protected abstract void createPool() throws Exception
      Create the pool.
      Throws:
      Exception - to avoid placing constraints on pooling APIs
    • getTarget

      public abstract @Nullable Object getTarget() throws Exception
      Acquire an object from the pool.
      Specified by:
      getTarget in interface TargetSource
      Returns:
      an object from the pool
      Throws:
      Exception - we may need to deal with checked exceptions from pool APIs, so we're forgiving with our exception signature
    • releaseTarget

      public abstract void releaseTarget(Object target) throws 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 getTarget()
      Throws:
      Exception - to allow pooling APIs to throw exception
      See Also:
    • getPoolingConfigMixin

      public DefaultIntroductionAdvisor getPoolingConfigMixin()
      Return an IntroductionAdvisor that provides a mixin exposing statistics about the pool maintained by this object.