org.springframework.ejb.access

## Class SimpleRemoteSlsbInvokerInterceptor

- java.lang.Object
- - org.springframework.jndi.JndiAccessor
  - - org.springframework.jndi.JndiLocatorSupport
    - - org.springframework.jndi.JndiObjectLocator
      - - org.springframework.ejb.access.AbstractSlsbInvokerInterceptor
        - - org.springframework.ejb.access.AbstractRemoteSlsbInvokerInterceptor
          - - org.springframework.ejb.access.SimpleRemoteSlsbInvokerInterceptor

- All Implemented Interfaces:
    Advice, Interceptor, MethodInterceptor, DisposableBean, InitializingBean
  Direct Known Subclasses:
    SimpleRemoteStatelessSessionProxyFactoryBean

      public class SimpleRemoteSlsbInvokerInterceptor
      extends AbstractRemoteSlsbInvokerInterceptor
      implements DisposableBean

  Basic invoker for a remote Stateless Session Bean. Designed for EJB 2.x, but works for EJB 3 Session Beans as well.

  "Creates" a new EJB instance for each invocation, or caches the session bean instance for all invocations (see `setCacheSessionBean(boolean)`). See `JndiObjectLocator` for info on how to specify the JNDI location of the target EJB.

  In a bean container, this class is normally best used as a singleton. However, if that bean container pre-instantiates singletons (as do the XML ApplicationContext variants) you may have a problem if the bean container is loaded before the EJB container loads the target EJB. That is because by default the JNDI lookup will be performed in the init method of this class and cached, but the EJB will not have been bound at the target location yet. The best solution is to set the "lookupHomeOnStartup" property to "false", in which case the home will be fetched on first access to the EJB. (This flag is only true by default for backwards compatibility reasons).

  This invoker is typically used with an RMI business interface, which serves as super-interface of the EJB component interface. Alternatively, this invoker can also proxy a remote SLSB with a matching non-RMI business interface, i.e. an interface that mirrors the EJB business methods but does not declare RemoteExceptions. In the latter case, RemoteExceptions thrown by the EJB stub will automatically get converted to Spring's unchecked RemoteAccessException.

  Since:
    09.05.2003
  Author:
    Rod Johnson, Juergen Hoeller
  See Also:
    `RemoteAccessException`, `AbstractSlsbInvokerInterceptor.setLookupHomeOnStartup(boolean)`, `AbstractSlsbInvokerInterceptor.setCacheHome(boolean)`, `AbstractRemoteSlsbInvokerInterceptor.setRefreshHomeOnConnectFailure(boolean)`

- - ### Field Summary

    - ### Fields inherited from class org.springframework.jndi.JndiLocatorSupport

      `CONTAINER_PREFIX`

    - ### Fields inherited from class org.springframework.jndi.JndiAccessor

      `logger`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `SimpleRemoteSlsbInvokerInterceptor()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `destroy()` Remove the cached session bean instance, if necessary.
    `protected Object` | `doInvoke(MethodInvocation invocation)` This implementation "creates" a new EJB instance for each invocation.
    `protected Object` | `getSessionBeanInstance()` Return an EJB component instance to delegate the call to.
    `protected void` | `refreshHome()` Reset the cached session bean instance, if necessary.
    `protected void` | `releaseSessionBeanInstance(EJBObject ejb)` Release the given EJB instance.
    `void` | `setCacheSessionBean(boolean cacheSessionBean)` Set whether to cache the actual session bean object.

    - ### Methods inherited from class org.springframework.ejb.access.AbstractRemoteSlsbInvokerInterceptor

      `getCreateMethod, invokeInContext, isConnectFailure, isHomeRefreshable, lookup, newSessionBeanInstance, refreshAndRetry, removeSessionBeanInstance, setHomeInterface, setRefreshHomeOnConnectFailure`

    - ### Methods inherited from class org.springframework.ejb.access.AbstractSlsbInvokerInterceptor

      `afterPropertiesSet, create, getHome, invoke, setCacheHome, setExposeAccessContext, setLookupHomeOnStartup`

    - ### Methods inherited from class org.springframework.jndi.JndiObjectLocator

      `getExpectedType, getJndiName, setExpectedType, setJndiName`

    - ### Methods inherited from class org.springframework.jndi.JndiLocatorSupport

      `convertJndiName, isResourceRef, lookup, lookup, setResourceRef`

    - ### Methods inherited from class org.springframework.jndi.JndiAccessor

      `getJndiEnvironment, getJndiTemplate, setJndiEnvironment, setJndiTemplate`

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### SimpleRemoteSlsbInvokerInterceptor

          public SimpleRemoteSlsbInvokerInterceptor()

  - ### Method Detail

    - #### setCacheSessionBean

          public void setCacheSessionBean(boolean cacheSessionBean)

      Set whether to cache the actual session bean object.

      Off by default for standard EJB compliance. Turn this flag on to optimize session bean access for servers that are known to allow for caching the actual session bean object.

      See Also:
        `AbstractSlsbInvokerInterceptor.setCacheHome(boolean)`

    - #### doInvoke

          protected Object doInvoke(MethodInvocation invocation)
                             throws Throwable

      This implementation "creates" a new EJB instance for each invocation. Can be overridden for custom invocation strategies.

      Alternatively, override `getSessionBeanInstance()` and `releaseSessionBeanInstance(javax.ejb.EJBObject)` to change EJB instance creation, for example to hold a single shared EJB component instance.

      Specified by:
        `doInvoke` in class `AbstractRemoteSlsbInvokerInterceptor`
      Parameters:
        `invocation` - the AOP method invocation
      Returns:
        the invocation result, if any
      Throws:
        `Throwable` - in case of invocation failure
      See Also:
        `AbstractSlsbInvokerInterceptor.getHome()`, `AbstractRemoteSlsbInvokerInterceptor.newSessionBeanInstance()`

    - #### getSessionBeanInstance

          protected Object getSessionBeanInstance()
                                           throws NamingException,
                                                  InvocationTargetException

      Return an EJB component instance to delegate the call to.

      The default implementation delegates to `AbstractRemoteSlsbInvokerInterceptor.newSessionBeanInstance()`.

      Returns:
        the EJB component instance
      Throws:
        `NamingException` - if thrown by JNDI
        `InvocationTargetException` - if thrown by the create method
      See Also:
        `AbstractRemoteSlsbInvokerInterceptor.newSessionBeanInstance()`

    - #### releaseSessionBeanInstance

          protected void releaseSessionBeanInstance(EJBObject ejb)

      Release the given EJB instance.

      The default implementation delegates to `AbstractRemoteSlsbInvokerInterceptor.removeSessionBeanInstance(javax.ejb.EJBObject)`.

      Parameters:
        `ejb` - the EJB component instance to release
      See Also:
        `AbstractRemoteSlsbInvokerInterceptor.removeSessionBeanInstance(javax.ejb.EJBObject)`

    - #### refreshHome

          protected void refreshHome()
                              throws NamingException

      Reset the cached session bean instance, if necessary.
      Overrides:
        `refreshHome` in class `AbstractSlsbInvokerInterceptor`
      Throws:
        `NamingException` - if thrown by the JNDI lookup
      See Also:
        `JndiObjectLocator.lookup()`, `AbstractSlsbInvokerInterceptor.getCreateMethod(java.lang.Object)`

    - #### destroy

          public void destroy()

      Remove the cached session bean instance, if necessary.
      Specified by:
        `destroy` in interface `DisposableBean`