Class LazyInitTargetSource

java.lang.Object

org.springframework.aop.target.AbstractBeanFactoryBasedTargetSource

org.springframework.aop.target.LazyInitTargetSource

All Implemented Interfaces:

Serializable, TargetClassAware, TargetSource, Aware, BeanFactoryAware

public class LazyInitTargetSource
extends AbstractBeanFactoryBasedTargetSource

TargetSource that lazily accesses a singleton bean from a BeanFactory.

Useful when a proxy reference is needed on initialization but the actual target object should not be initialized until first use. When the target bean is defined in an ApplicationContext (or a BeanFactory that is eagerly pre-instantiating singleton beans) it must be marked as "lazy-init" too, else it will be instantiated by said ApplicationContext (or BeanFactory) on startup.

For example:

<bean id="serviceTarget" class="example.MyService" lazy-init="true">
  ...
</bean>

<bean id="service" class="org.springframework.aop.framework.ProxyFactoryBean">
  <property name="targetSource">
    <bean class="org.springframework.aop.target.LazyInitTargetSource">
      <property name="targetBeanName"><idref local="serviceTarget"/></property>
    </bean>
  </property>
</bean>

The "serviceTarget" bean will not get initialized until a method on the "service" proxy gets invoked.

Subclasses can extend this class and override the postProcessTargetObject(Object) to perform some additional processing with the target object when it is first loaded.

Since:

1.1.4

Author:

Juergen Hoeller, Rob Harrop

See Also:

• BeanFactory.getBean(String)
• postProcessTargetObject(Object)
• Serialized Form

Field Summary

Fields inherited from class AbstractBeanFactoryBasedTargetSource

logger, targetBeanName

Constructor Summary

Constructors

Constructor	Description
LazyInitTargetSource()

Method Summary

Modifier and Type	Method	Description
Object	getTarget()	Return a target instance.
protected void	postProcessTargetObject(Object targetObject)	Subclasses may override this method to perform additional processing on the target object when it is first loaded.

Methods inherited from class AbstractBeanFactoryBasedTargetSource

copyFrom, equals, getBeanFactory, getTargetBeanName, getTargetClass, hashCode, setBeanFactory, setTargetBeanName, setTargetClass, toString

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface TargetSource

isStatic, releaseTarget

Constructor Details

LazyInitTargetSource

public LazyInitTargetSource()

Method Details

getTarget

public Object getTarget()
                 throws BeansException

Description copied from interface: TargetSource

Return a target instance. Invoked immediately before the AOP framework calls the "target" of an AOP method invocation.

Returns:

the target object which contains the joinpoint, or null if there is no actual target instance

Throws:

BeansException

postProcessTargetObject

protected void postProcessTargetObject(Object targetObject)

Subclasses may override this method to perform additional processing on the target object when it is first loaded.

Parameters:

targetObject - the target object that has just been instantiated (and configured)