org.springframework.orm.jdo.support
Class SpringPersistenceManagerProxyBean

java.lang.Object
  org.springframework.orm.jdo.support.SpringPersistenceManagerProxyBean

All Implemented Interfaces:

FactoryBean<PersistenceManager>, InitializingBean

public class SpringPersistenceManagerProxyBean
extends java.lang.Object
implements FactoryBean<PersistenceManager>, InitializingBean

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.

Since:

3.0

Author:

Juergen Hoeller

See Also:

StandardPersistenceManagerProxyBean, javax.jdo.PersistenceManagerFactory#getPersistenceManagerProxy(), PersistenceManagerFactoryUtils.getPersistenceManager(PersistenceManagerFactory, boolean), PersistenceManagerFactoryUtils.releasePersistenceManager(PersistenceManager, PersistenceManagerFactory)

persistenceManagerFactory

private PersistenceManagerFactory persistenceManagerFactory

jdoDialect

private JdoDialect jdoDialect

persistenceManagerInterface

private java.lang.Class<? extends PersistenceManager> persistenceManagerInterface

allowCreate

private boolean allowCreate

proxy

private PersistenceManager proxy

SpringPersistenceManagerProxyBean

public SpringPersistenceManagerProxyBean()

setPersistenceManagerFactory

public void setPersistenceManagerFactory(PersistenceManagerFactory persistenceManagerFactory)

Set the target PersistenceManagerFactory for this proxy.

getPersistenceManagerFactory

protected PersistenceManagerFactory getPersistenceManagerFactory()

Return the target PersistenceManagerFactory for this proxy.

setJdoDialect

public void setJdoDialect(JdoDialect jdoDialect)

Set the JDO dialect to use for this proxy.

Default is a DefaultJdoDialect based on the PersistenceManagerFactory's underlying DataSource, if any.

getJdoDialect

protected JdoDialect getJdoDialect()

Return the JDO dialect to use for this proxy.

setPersistenceManagerInterface

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

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

Default is the standard javax.jdo.PersistenceManager interface.

getPersistenceManagerInterface

protected java.lang.Class<? extends PersistenceManager> getPersistenceManagerInterface()

Return the PersistenceManager interface to expose.

setAllowCreate

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)

isAllowCreate

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.

afterPropertiesSet

public void afterPropertiesSet()

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

getObject

public PersistenceManager 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<PersistenceManager>

Returns:

an instance of the bean (can be null)

See Also:

FactoryBeanNotInitializedException

getObjectType

public java.lang.Class<? extends PersistenceManager> 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<PersistenceManager>

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<PersistenceManager>

Returns:

whether the exposed object is a singleton

See Also:

FactoryBean.getObject(), SmartFactoryBean.isPrototype()