public class TransactionAwarePersistenceManagerFactoryProxy extends java.lang.Object implements FactoryBean<PersistenceManagerFactory>
javax.jdo.PersistenceManagerFactory, returning the current thread-bound PersistenceManager (the Spring-managed transactional PersistenceManager or the single OpenPersistenceManagerInView PersistenceManager) on
getPersistenceManager(), if any.
getPersistenceManager() calls get seamlessly
PersistenceManager.close calls get forwarded to
The main advantage of this proxy is that it allows DAOs to work with a plain JDO PersistenceManagerFactory reference, while still participating in Spring's (or a J2EE server's) resource and transaction management. DAOs will only rely on the JDO API in such a scenario, without any Spring dependencies.
Note that the behavior of this proxy matches the behavior that the JDO spec defines for a PersistenceManagerFactory as exposed by a JCA connector, when deployed in a J2EE server. Hence, DAOs could seamlessly switch between a JNDI PersistenceManagerFactory and this proxy for a local PersistenceManagerFactory, receiving the reference through Dependency Injection. This will work without any Spring API dependencies in the DAO code!
It is usually preferable to write your JDO-based DAOs with Spring's
JdoTemplate, offering benefits such as consistent data access
exceptions instead of JDOExceptions at the DAO layer. However, Spring's
resource and transaction management (and Dependency Injection) will work
for DAOs written against the plain JDO API as well.
Of course, you can still access the target PersistenceManagerFactory even when your DAOs go through this proxy, by defining a bean reference that points directly at your target PersistenceManagerFactory bean.
|Modifier and Type||Class and Description|
Invocation handler that delegates getPersistenceManager calls on the PersistenceManagerFactory proxy to PersistenceManagerFactoryUtils for being aware of thread-bound transactions.
Invocation handler that delegates close calls on PersistenceManagers to PersistenceManagerFactoryUtils for being aware of thread-bound transactions.
|Modifier and Type||Field and Description|
|Constructor and Description|
|Modifier and Type||Method and Description|
Return an instance (possibly shared or independent) of the object managed by this factory.
Return the type of object that this FactoryBean creates, or
Return the target JDO PersistenceManagerFactory that this proxy delegates to.
Return whether the PersistenceManagerFactory proxy is allowed to create a non-transactional PersistenceManager when no transactional PersistenceManager can be found for the current thread.
Is the object managed by this factory a singleton? That is, will
Set whether the PersistenceManagerFactory proxy is allowed to create a non-transactional PersistenceManager when no transactional PersistenceManager can be found for the current thread.
Set the target JDO PersistenceManagerFactory that this proxy should delegate to.
private PersistenceManagerFactory target
private boolean allowCreate
private PersistenceManagerFactory proxy
public void setTargetPersistenceManagerFactory(PersistenceManagerFactory target)
public PersistenceManagerFactory getTargetPersistenceManagerFactory()
public void setAllowCreate(boolean allowCreate)
Default is "true". Can be turned off to enforce access to
transactional PersistenceManagers, which safely allows for DAOs
written to get a PersistenceManager without explicit closing
call without corresponding
protected boolean isAllowCreate()
public PersistenceManagerFactory getObject()
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
As of Spring 2.0, FactoryBeans are allowed to return
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.
public java.lang.Class<? extends PersistenceManagerFactory> getObjectType()
nullif 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.
nullif not known at the time of the call
public boolean isSingleton()
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
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
may explicitly indicate independent instances through its
SmartFactoryBean.isPrototype() method. Plain
implementations which do not implement this extended interface are
simply assumed to always return independent instances if the
isSingleton() implementation returns