org.springframework.remoting.rmi
Class RmiProxyFactoryBean

java.lang.Object
  org.springframework.remoting.support.RemoteAccessor
      org.springframework.remoting.support.UrlBasedRemoteAccessor
          org.springframework.remoting.support.RemoteInvocationBasedAccessor
              org.springframework.remoting.rmi.RmiClientInterceptor
                  org.springframework.remoting.rmi.RmiProxyFactoryBean

All Implemented Interfaces:

Advice, Interceptor, MethodInterceptor, BeanClassLoaderAware, FactoryBean, InitializingBean

public class RmiProxyFactoryBean
extends RmiClientInterceptor
implements FactoryBean, BeanClassLoaderAware

FactoryBean for RMI proxies, supporting both conventional RMI services and RMI invokers. Exposes the proxied service for use as a bean reference, using the specified service interface. Proxies will throw Spring's unchecked RemoteAccessException on remote invocation failure instead of RMI's RemoteException.

The service URL must be a valid RMI URL like "rmi://localhost:1099/myservice". RMI invokers work at the RmiInvocationHandler level, using the same invoker stub for any service. Service interfaces do not have to extend java.rmi.Remote or throw java.rmi.RemoteException. Of course, in and out parameters have to be serializable.

With conventional RMI services, this proxy factory is typically used with the RMI service interface. Alternatively, this factory can also proxy a remote RMI service with a matching non-RMI business interface, i.e. an interface that mirrors the RMI service methods but does not declare RemoteExceptions. In the latter case, RemoteExceptions thrown by the RMI stub will automatically get converted to Spring's unchecked RemoteAccessException.

The major advantage of RMI, compared to Hessian and Burlap, is serialization. Effectively, any serializable Java object can be transported without hassle. Hessian and Burlap have their own (de-)serialization mechanisms, but are HTTP-based and thus much easier to setup than RMI. Alternatively, consider Spring's HTTP invoker to combine Java serialization with HTTP-based transport.

Since:

13.05.2003

Author:

Juergen Hoeller

See Also:

RemoteAccessor.setServiceInterface(java.lang.Class), UrlBasedRemoteAccessor.setServiceUrl(java.lang.String), RmiClientInterceptor, RmiServiceExporter, Remote, RemoteException, RemoteAccessException, HessianProxyFactoryBean, BurlapProxyFactoryBean, HttpInvokerProxyFactoryBean

Field Summary

Fields inherited from class org.springframework.remoting.support.RemoteAccessor

logger

Constructor Summary

RmiProxyFactoryBean()

Method Summary

void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
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	setBeanClassLoader(ClassLoader classLoader) Callback that supplies the bean class loader to a bean instance.

Methods inherited from class org.springframework.remoting.rmi.RmiClientInterceptor

doInvoke, doInvoke, getStub, invoke, isConnectFailure, lookupStub, prepare, refreshAndRetry, setCacheStub, setLookupStubOnStartup, setRefreshStubOnConnectFailure, setRegistryClientSocketFactory

Methods inherited from class org.springframework.remoting.support.RemoteInvocationBasedAccessor

createRemoteInvocation, getRemoteInvocationFactory, recreateRemoteInvocationResult, setRemoteInvocationFactory

Methods inherited from class org.springframework.remoting.support.UrlBasedRemoteAccessor

getServiceUrl, setServiceUrl

Methods inherited from class org.springframework.remoting.support.RemoteAccessor

getServiceInterface, setServiceInterface

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RmiProxyFactoryBean

public RmiProxyFactoryBean()

Method Detail

setBeanClassLoader

public void setBeanClassLoader(ClassLoader classLoader)

Description copied from interface: BeanClassLoaderAware

Callback that supplies the bean class loader to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean's InitializingBean.afterPropertiesSet() method or a custom init-method.

Specified by:

setBeanClassLoader in interface BeanClassLoaderAware

Parameters:

classLoader - the owning class loader; may be null in which case a default ClassLoader must be used, for example the ClassLoader obtained via ClassUtils.getDefaultClassLoader()

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

Overrides:

afterPropertiesSet in class RmiClientInterceptor

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()