org.springframework.remoting.rmi

Class RmiProxyFactoryBean

  • All Implemented Interfaces:
    Advice, Interceptor, MethodInterceptor, Aware, BeanClassLoaderAware, FactoryBean<java.lang.Object>, InitializingBean


    public class RmiProxyFactoryBean
    extends RmiClientInterceptor
    implements FactoryBean<java.lang.Object>, 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, is serialization. Effectively, any serializable Java object can be transported without hassle. Hessian has its own (de-)serialization mechanisms, but is 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, HttpInvokerProxyFactoryBean
    • Constructor Detail

      • RmiProxyFactoryBean

        public RmiProxyFactoryBean()
    • Method Detail

      • afterPropertiesSet

        public void afterPropertiesSet()
        Description copied from interface: InitializingBean
        Invoked by the containing BeanFactory after it has set all bean properties and satisfied BeanFactoryAware, ApplicationContextAware etc.

        This method allows the bean instance to perform validation of its overall configuration and final initialization when all bean properties have been set.

        Specified by:
        afterPropertiesSet in interface InitializingBean
        Overrides:
        afterPropertiesSet in class RmiClientInterceptor
      • getObject

        public java.lang.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<java.lang.Object>
        Returns:
        an instance of the bean (can be null)
        See Also:
        FactoryBeanNotInitializedException
      • getObjectType

        public java.lang.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<java.lang.Object>
        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<T>)
      • 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.

        The default implementation returns true, since a FactoryBean typically manages a singleton instance.

        Specified by:
        isSingleton in interface FactoryBean<java.lang.Object>
        Returns:
        whether the exposed object is a singleton
        See Also:
        FactoryBean.getObject(), SmartFactoryBean.isPrototype()