org.springframework.beans.factory.config
Class AbstractFactoryBean

java.lang.Object
  extended by org.springframework.beans.factory.config.AbstractFactoryBean
All Implemented Interfaces:
FactoryBean, InitializingBean
Direct Known Subclasses:
ListFactoryBean, MapFactoryBean, ObjectFactoryCreatingFactoryBean, SetFactoryBean

public abstract class AbstractFactoryBean
extends Object
implements FactoryBean, InitializingBean

Simple template superclass for FactoryBean implementations thats allows for creating a singleton or a prototype, depending on a flag.

If the "singleton" flag is "true" (the default), this class will create once on initialization and subsequently return the singleton instance. Else, this class will create a new instance each time. Subclasses are responsible for implementing the abstract createInstance template method to actually create the objects to expose.

Since:
1.0.2
Author:
Juergen Hoeller, Keith Donald
See Also:
setSingleton(boolean), createInstance()

Field Summary
protected  Log logger
          Logger available to subclasses
 
Constructor Summary
AbstractFactoryBean()
           
 
Method Summary
 void afterPropertiesSet()
          Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected abstract  Object createInstance()
          Template method that subclasses must override to construct the object returned by this factory.
 Object getObject()
          Return an instance (possibly shared or independent) of the object managed by this factory.
 boolean isSingleton()
          Is the bean managed by this factory a singleton or a prototype?
 void setSingleton(boolean singleton)
          Set if a singleton should be created, or a new object on each request else.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.springframework.beans.factory.FactoryBean
getObjectType
 

Field Detail

logger

protected final Log logger
Logger available to subclasses

Constructor Detail

AbstractFactoryBean

public AbstractFactoryBean()
Method Detail

setSingleton

public final void setSingleton(boolean singleton)
Set if a singleton should be created, or a new object on each request else. Default is true (a singleton).


isSingleton

public final boolean isSingleton()
Description copied from interface: FactoryBean
Is the bean managed by this factory a singleton or a prototype? That is, will getObject() always return the same object?

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

Specified by:
isSingleton in interface FactoryBean
Returns:
if this bean is a singleton

afterPropertiesSet

public final void afterPropertiesSet()
                              throws Exception
Description copied from interface: InitializingBean
Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:
afterPropertiesSet in interface InitializingBean
Throws:
Exception - in the event of misconfiguration (such as failure to set an essential property) or if initialization fails.

getObject

public final Object getObject()
                       throws Exception
Description copied from interface: FactoryBean
Return an instance (possibly shared or independent) of the object managed by this factory. As with a BeanFactory, this allows support for both the Singleton and Prototype design pattern.

If this method returns null, the factory will consider the FactoryBean as not fully initialized and throw a corresponding FactoryBeanNotInitializedException.

Specified by:
getObject in interface FactoryBean
Returns:
an instance of the bean (should not be null; a null value will be considered as an indication of incomplete initialization)
Throws:
Exception - in case of creation errors
See Also:
FactoryBeanNotInitializedException

createInstance

protected abstract Object createInstance()
                                  throws Exception
Template method that subclasses must override to construct the object returned by this factory.

Invoked on initialization of this FactoryBean in case of a singleton; else, on each getObject() call.

Returns:
the object returned by this factory
Throws:
Exception - if an exception occured during object creation
See Also:
getObject()


Copyright (c) 2002-2005 The Spring Framework Project.