Top Description Inners Fields Constructors Methods
org.springframework.beans.factory.config

public Class ObjectFactoryCreatingFactoryBean

extends AbstractFactoryBean<ObjectFactory<Object>>
Class Inheritance
Imports
java.io.Serializable, org.springframework.beans.BeansException, org.springframework.beans.factory.BeanFactory, .ObjectFactory, org.springframework.lang.Nullable, org.springframework.util.Assert

A org.springframework.beans.factory.FactoryBean implementation that returns a value which is an org.springframework.beans.factory.ObjectFactory that in turn returns a bean sourced from a org.springframework.beans.factory.BeanFactory.

As such, this may be used to avoid having a client object directly calling org.springframework.beans.factory.BeanFactory#getBean(String) to get a (typically prototype) bean from a org.springframework.beans.factory.BeanFactory, which would be a violation of the inversion of control principle. Instead, with the use of this class, the client object can be fed an org.springframework.beans.factory.ObjectFactory instance as a property which directly returns only the one target bean (again, which is typically a prototype bean).

A sample config in an XML-based org.springframework.beans.factory.BeanFactory might look as follows:

<beans>

   <!-- Prototype bean since we have state -->
   <bean id="myService" class="a.b.c.MyService" scope="prototype"/>

   <bean id="myServiceFactory"
       class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBean">
     <property name="targetBeanName"><idref local="myService"/></property>
   </bean>

   <bean id="clientBean" class="a.b.c.MyClientBean">
     <property name="myServiceFactory" ref="myServiceFactory"/>
   </bean>

</beans>

The attendant MyClientBean class implementation might look something like this:

package a.b.c;

 import org.springframework.beans.factory.ObjectFactory;

 public class MyClientBean {

   private ObjectFactory<MyService> myServiceFactory;

   public void setMyServiceFactory(ObjectFactory<MyService> myServiceFactory) {
     this.myServiceFactory = myServiceFactory;
   }

   public void someBusinessMethod() {
     // get a 'fresh', brand new MyService instance
     MyService service = this.myServiceFactory.getObject();
     // use the service object to effect the business logic...
   }
 }

An alternate approach to this application of an object creational pattern would be to use the ServiceLocatorFactoryBean to source (prototype) beans. The ServiceLocatorFactoryBean approach has the advantage of the fact that one doesn't have to depend on any Spring-specific interface such as org.springframework.beans.factory.ObjectFactory, but has the disadvantage of requiring runtime class generation. Please do consult the ServiceLocatorFactoryBean JavaDoc for a fuller discussion of this issue.

Authors
Colin Sampaleanu, Juergen Hoeller
Since
1.0.2
See Also
org.springframework.beans.factory.ObjectFactory, ServiceLocatorFactoryBean

Nested and Inner Type Summary

Modifier and TypeClass and Description
private static class
ObjectFactoryCreatingFactoryBean.TargetBeanObjectFactory

Independent inner class - for serialization purposes.

Field Summary

Modifier and TypeField and Description
private String
Inherited from org.springframework.beans.factory.config.AbstractFactoryBean:
logger

Constructor Summary

AccessConstructor and Description
public

Method Summary

Modifier and TypeMethod and Description
public void
protected ObjectFactory<Object>
createInstance()

Implements abstract org.springframework.beans.factory.config.AbstractFactoryBean.createInstance.

Template method that subclasses must override to construct the object returned by this factory.

public Class<?>
getObjectType()

Implements abstract org.springframework.beans.factory.config.AbstractFactoryBean.getObjectType.

Implements org.springframework.beans.factory.FactoryBean.getObjectType.

This abstract method declaration mirrors the method in the FactoryBean interface, for a consistent offering of abstract template methods.

public void
setTargetBeanName(String targetBeanName)

Set the name of the target bean.

Inherited from org.springframework.beans.factory.config.AbstractFactoryBean:
destroydestroyInstancegetBeanFactorygetBeanTypeConvertergetEarlySingletonInterfacesgetObjectisSingletonsetBeanClassLoadersetBeanFactorysetSingleton

Field Detail

targetBeanNameback to summary
private String targetBeanName
Annotations
@Nullable

Constructor Detail

ObjectFactoryCreatingFactoryBeanback to summary
public ObjectFactoryCreatingFactoryBean()

Method Detail

afterPropertiesSetback to summary
public void afterPropertiesSet() throws Exception

Overrides org.springframework.beans.factory.config.AbstractFactoryBean.afterPropertiesSet.

Implements org.springframework.beans.factory.InitializingBean.afterPropertiesSet.

Doc from org.springframework.beans.factory.config.AbstractFactoryBean.afterPropertiesSet.

Eagerly create the singleton instance, if necessary.

Annotations
@Override
Exceptions
Exception:

Doc from org.springframework.beans.factory.InitializingBean.afterPropertiesSet.

in the event of misconfiguration (such as failure to set an essential property) or if initialization fails for any other reason

createInstanceback to summary
protected ObjectFactory<Object> createInstance()

Implements abstract org.springframework.beans.factory.config.AbstractFactoryBean.createInstance.

Doc from org.springframework.beans.factory.config.AbstractFactoryBean.createInstance.

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:ObjectFactory<Object>

the object returned by this factory

Annotations
@Override
getObjectTypeback to summary
public Class<?> getObjectType()

Implements abstract org.springframework.beans.factory.config.AbstractFactoryBean.getObjectType.

Implements org.springframework.beans.factory.FactoryBean.getObjectType.

Doc from org.springframework.beans.factory.config.AbstractFactoryBean.getObjectType.

This abstract method declaration mirrors the method in the FactoryBean interface, for a consistent offering of abstract template methods.

Returns:Class<?>

Doc from org.springframework.beans.factory.FactoryBean.getObjectType.

the type of object that this FactoryBean creates, or null if not known at the time of the call

Annotations
@Override
setTargetBeanNameback to summary
public void setTargetBeanName(String targetBeanName)

Set the name of the target bean.

The target does not have to be a non-singleton bean, but realistically always will be (because if the target bean were a singleton, then said singleton bean could simply be injected straight into the dependent object, thus obviating the need for the extra level of indirection afforded by this factory approach).

org.springframework.beans.factory.config back to summary

private Class ObjectFactoryCreatingFactoryBean.TargetBeanObjectFactory

extends Object
implements ObjectFactory<Object>, Serializable
Class Inheritance
  • java.lang.Object
  • org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBean.TargetBeanObjectFactory
All Implemented Interfaces
java.io.Serializable, org.springframework.beans.factory.ObjectFactory
Annotations
@SuppressWarnings:serial

Independent inner class - for serialization purposes.

Field Summary

Modifier and TypeField and Description
private final BeanFactory
private final String

Constructor Summary

AccessConstructor and Description
public
TargetBeanObjectFactory(BeanFactory beanFactory, String targetBeanName)

Method Summary

Modifier and TypeMethod and Description
public Object
getObject()

Implements org.springframework.beans.factory.ObjectFactory.getObject.

Return an instance (possibly shared or independent) of the object managed by this factory.

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

beanFactoryback to summary
private final BeanFactory beanFactory
targetBeanNameback to summary
private final String targetBeanName

Constructor Detail

TargetBeanObjectFactoryback to summary
public TargetBeanObjectFactory(BeanFactory beanFactory, String targetBeanName)

Method Detail

getObjectback to summary
public Object getObject() throws BeansException

Implements org.springframework.beans.factory.ObjectFactory.getObject.

Doc from org.springframework.beans.factory.ObjectFactory.getObject.

Return an instance (possibly shared or independent) of the object managed by this factory.

Returns:Object

the resulting instance

Annotations
@Override
Exceptions
BeansException:
in case of creation errors