public class

SpringPersistenceManagerProxyBean

extends JdoAccessor
implements FactoryBean<T>
java.lang.Object
   ↳ org.springframework.orm.jdo.JdoAccessor
     ↳ org.springframework.orm.jdo.support.SpringPersistenceManagerProxyBean

Class Overview

Proxy that implements the javax.jdo.PersistenceManager interface, delegating to the current thread-bound PersistenceManager (the Spring-managed transactional PersistenceManager or the single OpenPersistenceManagerInView PersistenceManager, if any) on each invocation. This class makes such a Spring-style PersistenceManager proxy available for bean references.

The main advantage of this proxy is that it allows DAOs to work with a plain JDO PersistenceManager reference in JDO 2.1 style (see javax.jdo.PersistenceManagerFactory#getPersistenceManagerProxy()), while still participating in Spring's resource and transaction management.

The behavior of this proxy matches the behavior that the JDO 2.1 spec defines for a PersistenceManager proxy. Hence, DAOs could seamlessly switch between StandardPersistenceManagerProxyBean and this Spring-style proxy, receiving the reference through Dependency Injection. This will work without any Spring API dependencies in the DAO code!

Note: In contrast to StandardPersistenceManagerProxyBean, this proxy works with JDO 2.0 and higher. It does not require JDO 2.1.

Summary

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Inherited Fields
From class org.springframework.orm.jdo.JdoAccessor
Public Constructors
SpringPersistenceManagerProxyBean()
Public Methods
void afterPropertiesSet()
Eagerly initialize the JDO dialect, creating a default one for the specified PersistenceManagerFactory if none set.
PersistenceManager getObject()
Return an instance (possibly shared or independent) of the object managed by this factory.
Class<? extends PersistenceManager> 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 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.

void setAllowCreate(boolean allowCreate)
Set whether the PersistenceManagerFactory proxy is allowed to create a non-transactional PersistenceManager when no transactional PersistenceManager can be found for the current thread.
void setPersistenceManagerInterface(Class<? extends PersistenceManager> persistenceManagerInterface)
Specify the PersistenceManager interface to expose, possibly including vendor extensions.
Protected Methods
Class<? extends PersistenceManager> getPersistenceManagerInterface()
Return the PersistenceManager interface to expose.
boolean isAllowCreate()
Return whether the PersistenceManagerFactory proxy is allowed to create a non-transactional PersistenceManager when no transactional PersistenceManager can be found for the current thread.
[Expand]
Inherited Methods
From class org.springframework.orm.jdo.JdoAccessor
From class java.lang.Object
From interface org.springframework.beans.factory.FactoryBean
From interface org.springframework.beans.factory.InitializingBean

Public Constructors

public SpringPersistenceManagerProxyBean ()

Public Methods

public void afterPropertiesSet ()

Eagerly initialize the JDO dialect, creating a default one for the specified PersistenceManagerFactory if none set.

public PersistenceManager getObject ()

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.

Returns
  • an instance of the bean (can be null)

public Class<? extends PersistenceManager> getObjectType ()

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.

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

public boolean isSingleton ()

Is the object managed by this factory a singleton? That is, will 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 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.

Returns
  • whether the exposed object is a singleton

public void setAllowCreate (boolean allowCreate)

Set whether the PersistenceManagerFactory proxy is allowed to create a non-transactional PersistenceManager when no transactional PersistenceManager can be found for the current thread.

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 (i.e. a PersistenceManagerFactory.getPersistenceManager() call without corresponding PersistenceManager.close() call).

See Also
  • org.springframework.orm.jdo.PersistenceManagerFactoryUtils#getPersistenceManager(javax.jdo.PersistenceManagerFactory, boolean)

public void setPersistenceManagerInterface (Class<? extends PersistenceManager> persistenceManagerInterface)

Specify the PersistenceManager interface to expose, possibly including vendor extensions.

Default is the standard javax.jdo.PersistenceManager interface.

Protected Methods

protected Class<? extends PersistenceManager> getPersistenceManagerInterface ()

Return the PersistenceManager interface to expose.

protected boolean isAllowCreate ()

Return whether the PersistenceManagerFactory proxy is allowed to create a non-transactional PersistenceManager when no transactional PersistenceManager can be found for the current thread.