public class

RmiProxyFactoryBean

extends RmiClientInterceptor
implements BeanClassLoaderAware FactoryBean<T>
java.lang.Object
   ↳ org.springframework.remoting.support.RemotingSupport
     ↳ 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

Class Overview

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.

See Also

Summary

[Expand]
Inherited Fields
From class org.springframework.remoting.support.RemotingSupport
Public Constructors
RmiProxyFactoryBean()
Public Methods
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? 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.

[Expand]
Inherited Methods
From class org.springframework.remoting.rmi.RmiClientInterceptor
From class org.springframework.remoting.support.RemoteInvocationBasedAccessor
From class org.springframework.remoting.support.UrlBasedRemoteAccessor
From class org.springframework.remoting.support.RemoteAccessor
From class org.springframework.remoting.support.RemotingSupport
From class java.lang.Object
From interface org.springframework.beans.factory.BeanClassLoaderAware
From interface org.springframework.beans.factory.FactoryBean
From interface org.springframework.beans.factory.InitializingBean

Public Constructors

public RmiProxyFactoryBean ()

Public Methods

public void afterPropertiesSet ()

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.

public Object 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<?> 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