The Spring Framework

org.springframework.transaction.jta
Class JotmFactoryBean

java.lang.Object
  extended by org.springframework.transaction.jta.JotmFactoryBean
All Implemented Interfaces:
DisposableBean, FactoryBean

public class JotmFactoryBean
extends Object
implements FactoryBean, DisposableBean

FactoryBean that retrieves the JTA UserTransaction/TransactionManager for ObjectWeb's JOTM. Will retrieve an already active JOTM instance if found (e.g. if running in JOnAS), else create a new local JOTM instance.

With JOTM, the same object implements both the UserTransaction and the TransactionManager interface, as returned by this FactoryBean.

A local JOTM instance is well-suited for working in conjunction with ObjectWeb's XAPool, e.g. with bean definitions like the following:

 <bean id="jotm" class="org.springframework.transaction.jta.JotmFactoryBean"/>

 <bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager">
   <property name="userTransaction" ref="jotm"/>
 </bean>

 <bean id="innerDataSource" class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown">
   <property name="transactionManager" ref="jotm"/>
   <property name="driverName" value="..."/>
   <property name="url" value="..."/>
   <property name="user" value="..."/>
   <property name="password" value="..."/>
 </bean>

 <bean id="dataSource" class="org.enhydra.jdbc.pool.StandardXAPoolDataSource" destroy-method="shutdown">
   <property name="dataSource" ref="innerDataSource"/>
   <property name="user" value="..."/>
   <property name="password" value="..."/>
   <property name="maxSize" value="..."/>
 </bean>
Note that Spring's JtaTransactionManager will automatically detect that the passed-in UserTransaction reference also implements the TransactionManager interface. Hence, it is not necessary to specify a separate reference for JtaTransactionManager's "transactionManager" property.

Implementation note: This FactoryBean uses JOTM's static access method to obtain the JOTM Current object, which implements both the UserTransaction and the TransactionManager interface, as mentioned above.

Since:
21.01.2004
Author:
Juergen Hoeller
See Also:
JtaTransactionManager.setUserTransaction(javax.transaction.UserTransaction), JtaTransactionManager.setTransactionManager(javax.transaction.TransactionManager), Current

Constructor Summary
JotmFactoryBean()
           
 
Method Summary
 void destroy()
          Stop the local JOTM instance, if created by this FactoryBean.
 org.objectweb.jotm.Jotm getJotm()
          Return the JOTM instance created by this factory bean, if any.
 Object getObject()
          Return an instance (possibly shared or independent) of the object managed by this factory.
 Class 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?
 void setDefaultTimeout(int defaultTimeout)
          Set the default transaction timeout for the JOTM instance.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

JotmFactoryBean

public JotmFactoryBean()
                throws NamingException
Throws:
NamingException
Method Detail

setDefaultTimeout

public void setDefaultTimeout(int defaultTimeout)
Set the default transaction timeout for the JOTM instance.

Should only be called for a local JOTM instance, not when accessing an existing (shared) JOTM instance.


getJotm

public org.objectweb.jotm.Jotm getJotm()
Return the JOTM instance created by this factory bean, if any. Will be null if an already active JOTM instance is used.

Application code should never need to access this.


getObject

public Object 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
Returns:
an instance of the bean (can be null)
See Also:
FactoryBeanNotInitializedException

getObjectType

public Class 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
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
Returns:
whether the exposed object is a singleton
See Also:
FactoryBean.getObject(), SmartFactoryBean.isPrototype()

destroy

public void destroy()
Stop the local JOTM instance, if created by this FactoryBean.

Specified by:
destroy in interface DisposableBean

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