Spring Framework

org.springframework.ui.velocity
Class VelocityEngineFactoryBean

java.lang.Object
  extended by org.springframework.ui.velocity.VelocityEngineFactory
      extended by org.springframework.ui.velocity.VelocityEngineFactoryBean
All Implemented Interfaces:
Aware, FactoryBean<org.apache.velocity.app.VelocityEngine>, InitializingBean, ResourceLoaderAware

public class VelocityEngineFactoryBean
extends VelocityEngineFactory
implements FactoryBean<org.apache.velocity.app.VelocityEngine>, InitializingBean, ResourceLoaderAware

Factory bean that configures a VelocityEngine and provides it as bean reference. This bean is intended for any kind of usage of Velocity in application code, e.g. for generating email content. For web views, VelocityConfigurer is used to set up a VelocityEngine for views.

The simplest way to use this class is to specify a "resourceLoaderPath"; you do not need any further configuration then. For example, in a web application context:

 <bean id="velocityEngine" class="org.springframework.ui.velocity.VelocityEngineFactoryBean">
   <property name="resourceLoaderPath" value="/WEB-INF/velocity/"/>
 </bean>
See the base class VelocityEngineFactory for configuration details.

Author:
Juergen Hoeller
See Also:
VelocityEngineFactory.setConfigLocation(org.springframework.core.io.Resource), VelocityEngineFactory.setVelocityProperties(java.util.Properties), VelocityEngineFactory.setResourceLoaderPath(java.lang.String), VelocityConfigurer

Field Summary
 
Fields inherited from class org.springframework.ui.velocity.VelocityEngineFactory
logger
 
Constructor Summary
VelocityEngineFactoryBean()
           
 
Method Summary
 void afterPropertiesSet()
          Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
 org.apache.velocity.app.VelocityEngine getObject()
          Return an instance (possibly shared or independent) of the object managed by this factory.
 java.lang.Class<? extends org.apache.velocity.app.VelocityEngine> getObjectType()
          Return the type of object that this FactoryBean creates, or null if not known in advance.
 boolean isSingleton()
          Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?
 
Methods inherited from class org.springframework.ui.velocity.VelocityEngineFactory
createVelocityEngine, getResourceLoader, initSpringResourceLoader, initVelocityResourceLoader, isPreferFileSystemAccess, newVelocityEngine, postProcessVelocityEngine, setConfigLocation, setOverrideLogging, setPreferFileSystemAccess, setResourceLoader, setResourceLoaderPath, setVelocityProperties, setVelocityPropertiesMap
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.springframework.context.ResourceLoaderAware
setResourceLoader
 

Constructor Detail

VelocityEngineFactoryBean

public VelocityEngineFactoryBean()
Method Detail

afterPropertiesSet

public void afterPropertiesSet()
                        throws java.io.IOException,
                               org.apache.velocity.exception.VelocityException
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:
java.io.IOException
org.apache.velocity.exception.VelocityException

getObject

public org.apache.velocity.app.VelocityEngine getObject()
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 FactoryBean is not fully initialized yet at the time of the call (for example because it is involved in a circular reference), throw a corresponding FactoryBeanNotInitializedException.

As of Spring 2.0, FactoryBeans are allowed to return null objects. The factory will consider this as normal value to be used; it will not throw a FactoryBeanNotInitializedException in this case anymore. FactoryBean implementations are encouraged to throw FactoryBeanNotInitializedException themselves now, as appropriate.

Specified by:
getObject in interface FactoryBean<org.apache.velocity.app.VelocityEngine>
Returns:
an instance of the bean (can be null)
See Also:
FactoryBeanNotInitializedException

getObjectType

public java.lang.Class<? extends org.apache.velocity.app.VelocityEngine> getObjectType()
Description copied from interface: FactoryBean
Return the type of object that this FactoryBean creates, or null if not known in advance.

This allows one to check for specific types of beans without instantiating objects, for example on autowiring.

In the case of implementations that are creating a singleton object, this method should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

NOTE: Autowiring will simply ignore FactoryBeans that return null here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

Specified by:
getObjectType in interface FactoryBean<org.apache.velocity.app.VelocityEngine>
Returns:
the type of object that this FactoryBean creates, or null if not known at the time of the call
See Also:
ListableBeanFactory.getBeansOfType(java.lang.Class)

isSingleton

public boolean isSingleton()
Description copied from interface: FactoryBean
Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

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

NOTE: This method returning false does not necessarily indicate that returned objects are independent instances. An implementation of the extended SmartFactoryBean interface may explicitly indicate independent instances through its SmartFactoryBean.isPrototype() method. Plain FactoryBean implementations which do not implement this extended interface are simply assumed to always return independent instances if the isSingleton() implementation returns false.

Specified by:
isSingleton in interface FactoryBean<org.apache.velocity.app.VelocityEngine>
Returns:
whether the exposed object is a singleton
See Also:
FactoryBean.getObject(), SmartFactoryBean.isPrototype()

Spring Framework