Hi, As it's documentation [1] mentions, the usage of the @Priority annotation should be defined by the classes it is used on:
"The effect of using the Priority annotation in any particular instance is defined by other specifications that define the use of a specific class. For example, the Interceptors specification defines the use of priorities on interceptors to control the order in which interceptors are called." Therefore, I suggest we use the @Priority annotation on components that need it and that like to specify the order in which they are *used* (i.e. perform their main task). Priorities on other behaviors that are added to a component (for example through interfaces like Initializable or Disposable, interfaces which are not components themselves) should provide their own specialized (behavior-driven) priority annotations (e.g. @DisposePriority, @InitializationPriority, etc.). Note: If we want to explore the possibility of using our own generic Priority annotation, we need to consider the fact that multiple annotations on the same java class is only supported [1] starting with java 1.8. Until then, the commonly used workaround [3] seems cumbersome to use. Thanks, Eduard ---------- [1] http://docs.oracle.com/javaee/7/api/javax/annotation/Priority.html [2] http://bugs.java.com/bugdatabase/view_bug.do?bug_id=7151010 [3] http://stackoverflow.com/questions/1554112/multiple-annotations-of-the-same-type-on-one-element On Thu, Mar 12, 2015 at 10:41 AM, [email protected] <[email protected]> wrote: > Hi devs, > > As part of http://jira.xwiki.org/browse/XWIKI-11905, Edy has started > using the Java @Priority annotation. > > This seems very good and I personally didn’t know about this annotation > before (maybe it’s been introduced not that long ago?). So for me it raises > the question of: do we want to use this annotation more and how does it > compare with what we’ve done so far. > > I can think of a few places that could have used it: > > * Macros.get/setPriority(). It should be possible to add support for > @Priority and modify MacroTransformation to use that annotation. > * Transformations. We have a jira issue opened for adding support for > Priority in Transformation’s executions (in TransformationManager). > * @DisposePriority (used by ECM). > * TranslationBundle.get/setPriority() > * … and probably some other places… > > However, I think there’s a namespacing problem. For example imagine that > we code a Macro and set @Priority on that Macro component. The ECM could > interpret it as a dispose priority while the MacroTransformation could > interpret it as an execution priority… > > Globally I think that use an annotation for expressing priority is great > and much better than what we’ve done in the past with get/setPriority() > methods. It’s better because priority is not a business concept and we’re > polluting the business interface with it. > > Now, in order to fix the namespacing issue, I think that the best solution > is that each module requiring some priority should introduce its own > annotation and should NOT depend on the @Priority one from the JDK (i.e. we > ban the usage of it). > > WDYT? > > Thanks > -Vincent > > > W > _______________________________________________ > devs mailing list > [email protected] > http://lists.xwiki.org/mailman/listinfo/devs > _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
