C# Class Spring.Messaging.Nms.Listener.Adapter.MessageListenerAdapter

Message listener adapter that delegates the handling of messages to target listener methods via reflection, with flexible message type conversion. Allows listener methods to operate on message content types, completely independent from the NMS API.

By default, the content of incoming messages gets extracted before being passed into the target listener method, to let the target method operate on message content types such as String or byte array instead of the raw Message. Message type conversion is delegated to a Spring IMessageConverter. By default, a SimpleMessageConverter will be used. (If you do not want such automatic message conversion taking place, then be sure to set the MessageConverter property to null.)

If a target listener method returns a non-null object (typically of a message content type such as String or byte array), it will get wrapped in a NMS Message and sent to the response destination (either the NMS "reply-to" destination or the defaultResponseDestination specified.

The sending of response messages is only available when using the ISessionAwareMessageListener entry point (typically through a Spring message listener container). Usage as standard NMS MessageListener does not support the generation of response messages.

Consult the reference documentation for examples of method signatures compliant with this adapter class.

Inheritance: IMessageListener, ISessionAwareMessageListener

Show file Open project: spring-projects/spring-net Class Usage Examples

Public Properties

Property	Type	Description
ORIGINAL_DEFAULT_HANDLER_METHOD	string

Public Methods

Method	Description
MessageListenerAdapter ( ) : System	Initializes a new instance of the MessageListenerAdapter class with default settings.
MessageListenerAdapter ( object handlerObject ) : System	Initializes a new instance of the MessageListenerAdapter class for the given handler object
OnMessage ( IMessage message ) : void	Standard JMS {@link MessageListener} entry point. Delegates the message to the target listener method, with appropriate conversion of the message arguments In case of an exception, the HandleListenerException method will be invoked. Note Does not support sending response messages based on result objects returned from listener methods. Use the ISessionAwareMessageListener entry point (typically through a Spring message listener container) for handling result objects as well.
OnMessage ( IMessage message, ISession session ) : void	Spring ISessionAwareMessageListener entry point. Delegates the message to the target listener method, with appropriate conversion of the message argument. If the target method returns a non-null object, wrap in a NMS message and send it back.

Protected Methods

Method	Description
BuildMessage ( ISession session, Object result ) : IMessage	Builds a JMS message to be sent as response based on the given result object.
GetHandlerMethodName ( IMessage originalIMessage, object extractedMessage ) : string	Gets the name of the listener method that is supposed to handle the given message. The default implementation simply returns the configured default listener method, if any.
GetResponseDestination ( IMessage request, IMessage response, ISession session ) : IDestination	Determine a response destination for the given message. The default implementation first checks the JMS Reply-To Destination of the supplied request; if that is not `null` it is returned; if it is `null`, then the configured DefaultResponseDestination default response destination is returned; if this too is `null`, then an InvalidDestinationExceptionis thrown.
HandleListenerException ( Exception ex ) : void	Handle the given exception that arose during listener execution. The default implementation logs the exception at error level. This method only applies when used as standard NMS MessageListener. In case of the Spring ISessionAwareMessageListener mechanism, exceptions get handled by the caller instead.
HandleResult ( object result, IMessage request, ISession session ) : void	Handles the given result object returned from the listener method, sending a response message back.
InitDefaultStrategies ( ) : void	Initialize the default implementations for the adapter's strategies.
PostProcessProducer ( IMessageProducer producer, IMessage response ) : void	Post-process the given message producer before using it to send the response. The default implementation is empty.
PostProcessResponse ( IMessage request, IMessage response ) : void	Post-process the given response message before it will be sent. The default implementation sets the response's correlation id to the request message's correlation id.
ResolveDefaultResponseDestination ( ISession session ) : IDestination	Resolves the default response destination into a Destination, using this accessor's IDestinationResolver in case of a destination name.
SendResponse ( ISession session, IDestination destination, IMessage response ) : void	Sends the given response message to the given destination.

Private Methods

Method	Description
ExtractMessage ( IMessage message ) : object	Extract the message body from the given message.

Method Details

BuildMessage() protected method

Builds a JMS message to be sent as response based on the given result object.

If there was an error in message conversion if thrown by NMS API methods

protected BuildMessage ( ISession session, Object result ) : IMessage
session	ISession	The JMS Session to operate on.
result	Object	The content of the message, as returned from the listener method.
return	IMessage

GetHandlerMethodName() protected method

Gets the name of the listener method that is supposed to handle the given message. The default implementation simply returns the configured default listener method, if any.

if thrown by NMS API methods

protected GetHandlerMethodName ( IMessage originalIMessage, object extractedMessage ) : string
originalIMessage	IMessage	The NMS request message.
extractedMessage	object	The converted JMS request message, /// to be passed into the listener method as argument.
return	string

GetResponseDestination() protected method

Determine a response destination for the given message.

The default implementation first checks the JMS Reply-To Destination of the supplied request; if that is not null it is returned; if it is null, then the configured DefaultResponseDestination default response destination is returned; if this too is null, then an InvalidDestinationExceptionis thrown.

if thrown by NMS API methods if no destination can be determined.

protected GetResponseDestination ( IMessage request, IMessage response, ISession session ) : IDestination
request	IMessage	The original incoming message.
response	IMessage	The outgoing message about to be sent.
session	ISession	The session to operate on.
return	IDestination

HandleListenerException() protected method

Handle the given exception that arose during listener execution. The default implementation logs the exception at error level.

This method only applies when used as standard NMS MessageListener. In case of the Spring ISessionAwareMessageListener mechanism, exceptions get handled by the caller instead.

protected HandleListenerException ( Exception ex ) : void
ex	System.Exception	The exception to handle.
return	void

HandleResult() protected method

Handles the given result object returned from the listener method, sending a response message back.

protected HandleResult ( object result, IMessage request, ISession session ) : void
result	object	The result object to handle (never `null`).
request	IMessage	The original request message.
session	ISession	The session to operate on (may be `null`).
return	void

InitDefaultStrategies() protected method

Initialize the default implementations for the adapter's strategies.

protected InitDefaultStrategies ( ) : void
return	void

MessageListenerAdapter() public method

Initializes a new instance of the MessageListenerAdapter class with default settings.

public MessageListenerAdapter ( ) : System
return	System

MessageListenerAdapter() public method

Initializes a new instance of the MessageListenerAdapter class for the given handler object

public MessageListenerAdapter ( object handlerObject ) : System
handlerObject	object	The delegate object.
return	System

OnMessage() public method

Standard JMS {@link MessageListener} entry point.

Delegates the message to the target listener method, with appropriate conversion of the message arguments

In case of an exception, the HandleListenerException method will be invoked. Note Does not support sending response messages based on result objects returned from listener methods. Use the ISessionAwareMessageListener entry point (typically through a Spring message listener container) for handling result objects as well.

public OnMessage ( IMessage message ) : void
message	IMessage	The incoming message.
return	void

OnMessage() public method

Spring ISessionAwareMessageListener entry point.

Delegates the message to the target listener method, with appropriate conversion of the message argument. If the target method returns a non-null object, wrap in a NMS message and send it back.

public OnMessage ( IMessage message, ISession session ) : void
message	IMessage	The incoming message.
session	ISession	The session to operate on.
return	void

PostProcessProducer() protected method

Post-process the given message producer before using it to send the response. The default implementation is empty.

protected PostProcessProducer ( IMessageProducer producer, IMessage response ) : void
producer	IMessageProducer	The producer that will be used to send the message.
response	IMessage	The outgoing message about to be sent.
return	void

PostProcessResponse() protected method

Post-process the given response message before it will be sent. The default implementation sets the response's correlation id to the request message's correlation id.

if thrown by NMS API methods

protected PostProcessResponse ( IMessage request, IMessage response ) : void
request	IMessage	The original incoming message.
response	IMessage	The outgoing JMS message about to be sent.
return	void

ResolveDefaultResponseDestination() protected method

Resolves the default response destination into a Destination, using this accessor's IDestinationResolver in case of a destination name.

protected ResolveDefaultResponseDestination ( ISession session ) : IDestination
session	ISession	The session to operate on.
return	IDestination

SendResponse() protected method

Sends the given response message to the given destination.

protected SendResponse ( ISession session, IDestination destination, IMessage response ) : void
session	ISession	The session to operate on.
destination	IDestination	The destination to send to.
response	IMessage	The outgoing message about to be sent.
return	void

Property Details

ORIGINAL_DEFAULT_HANDLER_METHOD public static property

The default handler method name.

public static string ORIGINAL_DEFAULT_HANDLER_METHOD
return	string