Spring Framework

org.springframework.jms.remoting
Class JmsInvokerServiceExporter

java.lang.Object
  extended by org.springframework.remoting.support.RemotingSupport
      extended by org.springframework.remoting.support.RemoteExporter
          extended by org.springframework.remoting.support.RemoteInvocationBasedExporter
              extended by org.springframework.jms.remoting.JmsInvokerServiceExporter
All Implemented Interfaces:
Aware, BeanClassLoaderAware, InitializingBean, SessionAwareMessageListener<javax.jms.Message>

public class JmsInvokerServiceExporter
extends RemoteInvocationBasedExporter
implements SessionAwareMessageListener<javax.jms.Message>, InitializingBean

JMS message listener that exports the specified service bean as a JMS service endpoint, accessible via a JMS invoker proxy.

Note that this class implements Spring's SessionAwareMessageListener interface, since it requires access to the active JMS Session. Hence, this class can only be used with message listener containers which support the SessionAwareMessageListener interface (e.g. Spring's DefaultMessageListenerContainer).

Thanks to James Strachan for the original prototype that this JMS invoker mechanism was inspired by!

Since:
2.0
Author:
Juergen Hoeller, James Strachan
See Also:
JmsInvokerClientInterceptor, JmsInvokerProxyFactoryBean

Field Summary
 
Fields inherited from class org.springframework.remoting.support.RemotingSupport
logger
 
Constructor Summary
JmsInvokerServiceExporter()
           
 
Method Summary
 void afterPropertiesSet()
          Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected  javax.jms.Message createResponseMessage(javax.jms.Message request, javax.jms.Session session, RemoteInvocationResult result)
          Create the invocation result response message.
protected  RemoteInvocation onInvalidRequest(javax.jms.Message requestMessage)
          Callback that is invoked by readRemoteInvocation(javax.jms.Message) when it encounters an invalid request message.
 void onMessage(javax.jms.Message requestMessage, javax.jms.Session session)
          Callback for processing a received JMS message.
protected  RemoteInvocation readRemoteInvocation(javax.jms.Message requestMessage)
          Read a RemoteInvocation from the given JMS message.
 void setIgnoreInvalidRequests(boolean ignoreInvalidRequests)
          Set whether invalidly formatted messages should be discarded.
 void setMessageConverter(MessageConverter messageConverter)
          Specify the MessageConverter to use for turning request messages into RemoteInvocation objects, as well as RemoteInvocationResult objects into response messages.
protected  void writeRemoteInvocationResult(javax.jms.Message requestMessage, javax.jms.Session session, RemoteInvocationResult result)
          Send the given RemoteInvocationResult as a JMS message to the originator.
 
Methods inherited from class org.springframework.remoting.support.RemoteInvocationBasedExporter
getRemoteInvocationExecutor, invoke, invokeAndCreateResult, setRemoteInvocationExecutor
 
Methods inherited from class org.springframework.remoting.support.RemoteExporter
checkService, checkServiceInterface, getExporterName, getProxyForService, getService, getServiceInterface, setInterceptors, setRegisterTraceInterceptor, setService, setServiceInterface
 
Methods inherited from class org.springframework.remoting.support.RemotingSupport
getBeanClassLoader, overrideThreadContextClassLoader, resetThreadContextClassLoader, setBeanClassLoader
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

JmsInvokerServiceExporter

public JmsInvokerServiceExporter()
Method Detail

setMessageConverter

public void setMessageConverter(MessageConverter messageConverter)
Specify the MessageConverter to use for turning request messages into RemoteInvocation objects, as well as RemoteInvocationResult objects into response messages.

Default is a SimpleMessageConverter, using a standard JMS ObjectMessage for each invocation / invocation result object.

Custom implementations may generally adapt Serializables into special kinds of messages, or might be specifically tailored for translating RemoteInvocation(Result)s into specific kinds of messages.


setIgnoreInvalidRequests

public void setIgnoreInvalidRequests(boolean ignoreInvalidRequests)
Set whether invalidly formatted messages should be discarded. Default is "true".

Switch this flag to "false" to throw an exception back to the listener container. This will typically lead to redelivery of the message, which is usually undesirable - since the message content will be the same (that is, still invalid).


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

onMessage

public void onMessage(javax.jms.Message requestMessage,
                      javax.jms.Session session)
               throws javax.jms.JMSException
Description copied from interface: SessionAwareMessageListener
Callback for processing a received JMS message.

Implementors are supposed to process the given Message, typically sending reply messages through the given Session.

Specified by:
onMessage in interface SessionAwareMessageListener<javax.jms.Message>
Parameters:
requestMessage - the received JMS message (never null)
session - the underlying JMS Session (never null)
Throws:
javax.jms.JMSException - if thrown by JMS methods

readRemoteInvocation

protected RemoteInvocation readRemoteInvocation(javax.jms.Message requestMessage)
                                         throws javax.jms.JMSException
Read a RemoteInvocation from the given JMS message.

Parameters:
requestMessage - current request message
Returns:
the RemoteInvocation object (or null in case of an invalid message that will simply be ignored)
Throws:
javax.jms.JMSException - in case of message access failure

writeRemoteInvocationResult

protected void writeRemoteInvocationResult(javax.jms.Message requestMessage,
                                           javax.jms.Session session,
                                           RemoteInvocationResult result)
                                    throws javax.jms.JMSException
Send the given RemoteInvocationResult as a JMS message to the originator.

Parameters:
requestMessage - current request message
session - the JMS Session to use
result - the RemoteInvocationResult object
Throws:
javax.jms.JMSException - if thrown by trying to send the message

createResponseMessage

protected javax.jms.Message createResponseMessage(javax.jms.Message request,
                                                  javax.jms.Session session,
                                                  RemoteInvocationResult result)
                                           throws javax.jms.JMSException
Create the invocation result response message.

The default implementation creates a JMS ObjectMessage for the given RemoteInvocationResult object. It sets the response's correlation id to the request message's correlation id, if any; otherwise to the request message id.

Parameters:
request - the original request message
session - the JMS session to use
result - the invocation result
Returns:
the message response to send
Throws:
javax.jms.JMSException - if creating the messsage failed

onInvalidRequest

protected RemoteInvocation onInvalidRequest(javax.jms.Message requestMessage)
                                     throws javax.jms.JMSException
Callback that is invoked by readRemoteInvocation(javax.jms.Message) when it encounters an invalid request message.

The default implementation either discards the invalid message or throws a MessageFormatException - according to the "ignoreInvalidRequests" flag, which is set to "true" (that is, discard invalid messages) by default.

Parameters:
requestMessage - the invalid request message
Returns:
the RemoteInvocation to expose for the invalid request (typically null in case of an invalid message that will simply be ignored)
Throws:
javax.jms.JMSException - in case of the invalid request supposed to lead to an exception (instead of ignoring it)
See Also:
readRemoteInvocation(javax.jms.Message), setIgnoreInvalidRequests(boolean)

Spring Framework