[jboss-jira] [JBoss JIRA] Commented: (JBESB-192) Listener implementations need to perform the payload to Message wrapping, not the AbstractListener

Listener implementations need to perform the payload to Message wrapping, not the AbstractListener -------------------------------------------------------------------------------------------------- Key: JBESB-192 URL: http://jira.jboss.com/jira/browse/JBESB-192 Project: JBoss ESB Issue Type: Bug Security Level: Public(Everyone can see) Affects Versions: 4.0 Reporter: Tom Fennelly Assigned To: Mark Little Priority: Blocker Fix For: 4.1 I may be missing something here but, I think there's an issue with the Listeners/Action/Messages that probably requires more immediate attention. The AbstractListener calls the receive method of its implementation (DirectoryPoller etc) in order to get messages from the delivery channel associated with the implementation. At the moment, the receive method returns an Object[] and AbstractListener does the job of converting/wrapping these Objects into Message implementations before pushing the Message instances through the associated pipeline for processing. The AbstractListener also performs the job of triggering "lifecycle" events on the implementation i.e. processingError and processingComplete. In order for these method implementations to perform the appropriate "channel specific" tasks relating to the processing of the message, they need access to "special" info that should be hidden in the message and not accessible to anyone else other than that Listener impl. Hopefully this will make more sense through an example.... The DirectoryPoller listens on the Filesystem for file based message. It manage the lifecycle of these messages as follows: 1. Before it's receive method impl returns the java.io.File associated with the message, it renames the file to "working" so that the file is not picked up for processing again. In fact, it actually returns an extension of java.io.File (WorkingFile) which contains "hidden" info that the Listener uses when message lifecycle events are called (processingError and processingComplete). 2. In response to a call to it's "processingError" implementation, it should get passed the original message object it returned from it's receive method (WorkingFile). WorkingFile is a inner class to DirectoryPoller and it contains a few private methods that only WorkingFile and DirectoryPoller can call. In the case of processingError being called, the DirectoryPoller wants to call the private method "renameToError". 3. In response to a call to it's "processingComplete" implementation, the DirectoryPoller wants to call the private method "renameToDone". The Issue: The AbstractListener implementations should be doing the wrapping of the message payload objects in the relevant Message implementations (not the AbstractListener itself as is currently the case). This way, the channel specific listener implementation can add the channel specific info it needs to the message before returning it for pipeline processing (e.g. the rename to error/done file names etc in the case of the DirectoryPoller). This also means that the receive method definition would need to be changed to return a Message[] (instead of an Object[]) and the lifecycle management methods (processingError and processingComplete) changed to take type Message (Vs type Object). Without making these changes, the lifecycle info will very likely get lost in the pipeline because it's currently being set on the Message body/payload, which will very likely get changed during pipeline processing.