| Re: [m2e-users] Transforming class files in an M2E extension |
|
The consuming module only has the transformed classes on the classpath. The module with transformed classes does have the original classes on the classpath using an optional dependency. However, it does not seem to be a conflict between classes on the classpath. I tried generating an additional class (one that does not exist in the original classes), and this class is also not picked up. It seems Eclipse does not see classes in workspace modules when there is no source for those classes. Could this be the case?
Best regards, Emond Papegaaij
On Monday 20 January 2014 09:09:57 Igor Fedorenko wrote: > What does classpath of the consuming project look like? Does it include > both original classes and generated ones? > > Generally, I recommend against split packages (using OSGi terminology), > especially if you have exact the same classnames in different modules. > > -- > Regards, > Igor > > On 1/20/2014, 8:50, Emond Papegaaij wrote: > > We are generating new class files, based on existing class files. For > > example, if module a contains 'com.mycompany.Foo', we are generaing > > 'com.mycompany.Foo' in module b based on the class in module a. It's the > > same classname, but different bytecode. The files do contain the right > > contents on the file system (verified with javap). > > > > With "Eclipse does not see the generated classes", I mean that classes > > using these classes have compile errors, type completion does not work, > > 'Open type' does not work. I can see the files in the project explorer > > (in target/classes), but Eclipse does not seem to know about the types. > > > > The Maven Workspace Build view lists all classes produced by the plugin, > > so it seems BuildContext is working fine. > > > > Best regards, > > > > Emond Papegaaij > > > > On Monday 20 January 2014 07:57:34 Igor Fedorenko wrote: > > > Are you generating new class files or changing existing class files? > > > > > > > > > > > > Can you explain what "Eclipse does not see the generated classes" > > > means? > > > > > > > > > > > > Can you check if class file contents is as expected on filesystem? > > > > > > > > > > > > You may also want to check Maven Workspace Build view, which should > > > show > > > > > > if your mojo is executed, what input files it gets and what output > > > files > > > > > > it produces throw BuildContext API. (note that the view is "paused" by > > > > > > default, you need to click pause button to enable recording). > > > > > > > > > > > > -- > > > > > > Regards, > > > > > > Igor > > > > > > On 1/20/2014, 7:32, Emond Papegaaij wrote: > > > > I've changed the maven plugin to use BuildContext, but Eclipse is > > > > still > > > > > > > > having issues. It no longer triggers an endless build (even with > > > > > > > > runOnIncremental), but Eclipse does not see the generated classes. > > > > The > > > > > > > > transformed class files are visible in target/classes in Eclipse, but > > > > > > > > the modules depending on them do not see them. Also, 'Open type' does > > > > > > > > not show them. Did I miss anything? I do use > > > > > > > > buildContext.newFileOutputStream to generate the files. > > > > > > > > > > > > > > > > Best regards, > > > > > > > > > > > > > > > > Emond Papegaaij > > > > > > > > On Saturday 18 January 2014 22:18:19 you wrote: > > > > > You are right, both the transformer and the transformed classes are > > > > > > > > in the > > > > > > > > > same project, but that can be changed. The buildcontext approach > > > > > > > > seems the > > > > > > > > > easiest for now. If I understand it correctly, I only have to > > > > > improve > > > > > > > > > > the > > > > > > > > > > > > > > > > > > > > plugin to support incremental builds and use execute mapping in > > > > > m2e. > > > > > > > > > > Even > > > > > > > > > > > > > > > > > > > > if it does not work, I've at least improved the plugin :). I'll > > > > give it > > > > > > > a > > > > > > > > > > > > > > > > > > > > try next week. Thanks for the help. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Best regards, > > > > > > > > > > > > > > > > > > > > Emond Papegaaij > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Sat, Jan 18, 2014 at 5:34 PM, Igor Fedorenko > > > > > <igor@xxxxxxxxxxxxxx> > > > > > > > > wrote: > > > > > > If I read this correctly, you want to have both the transformer > > > > > > and > > > > > > > > > > > > the > > > > > > > > > > > > > > > > > > > > > > > > classes to be transformed in your workspace. This means that > > > > Eclipse > > > > > > > > workspace will have to first compile transformer classes and them > > > > > > > > > > > > > > > > > > > > > > > > immediately execute them. Even if this can be done, which I am > > > > > > not > > > > > > > > sure, > > > > > > > > > > I strongly advice against this because problems with > > > > transformer can > > > > > > > > crash your eclipse instance, for example. Tracking dependency > > > > between > > > > > > > > transformer and classes to be transformed is another problem. You > > > > > > > > > > > > > > > > > > > > > > > > probably want to move transformer to a separate project, deploy > > > > to a > > > > > > > > maven repository and consume it in a binary form. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > As for manipulating .class files inside Eclipse workspace, this > > > > > > is > > > > > > > > kinda > > > > > > > > > > tricky. I believe the correct way to do this is to implement > > > > > > > > > > > > > > > > > > > > > > > > org.eclipse.jdt.core.compiler.CompilationParticipant but this > > > > > > most > > > > > > > > > > > > > > > > > > > > > > > > likely means duplicating logic from javassist-maven-plugin. > > > > Wiki [1] > > > > > > > > gives some pointers how to "map" javassist-maven-plugin to m2e > > > > > > > > > > > > > > > > > > > > > > > > extension, but I don't have example that show use of > > > > > > > > > > > > > > > > > > > > > > > > CompilationParticipant. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > "Less" correct way, which may or may not work, is to invoke > > > > > > > > > > > > > > > > > > > > > > > > javassist-maven-plugin during Eclipse workspace build. I would > > > > > > > > recommend > > > > > > > > > > changing javassist-maven-plugin to use BuildContext API as > > > > explain in > > > > > > > > wiki [2] > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [1] http://wiki.eclipse.org/M2E_Extension_Development > > > > > > > > > > > > > > > > > > > > > > > > [2] http://wiki.eclipse.org/M2E_compatible_maven_plugins > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > > > > > > > > > > > Igor > > > > > > > > > > > > On 1/18/2014, 10:46, Emond Papegaaij wrote: > > > > > >> Hi all, > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> Having some issues with a maven plugin that transforms class > > > > > >> files > > > > > >> > > > > > >> in > > > > > >> > > > > > >> > > > > > >> > > > > > >> M2E (endless builds), I decided to try to write an extension (my > > > > > > > > first) > > > > > > > > > >> that handles the integration, but I need some help. The > > > > > >> > > > > > >> > > > > > >> > > > > > >> javassist-maven-plugin takes classes from the project class > > > > > >> path, > > > > > > > > passes > > > > > > > > > >> them through a transformer and writes new class files. A typical > > > > > > > > project > > > > > > > > > >> setup looks like this: > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> parent with modules: > > > > > >> > > > > > >> > > > > > >> > > > > > >> - module a with classes to be transformed > > > > > >> > > > > > >> > > > > > >> > > > > > >> - module b with transformer and javassist-maven-plugin, > > > > destination > > > > > > > >> of > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> transformed classes, has optional dependency on module a to stop > > > > > >> > > > > > >> > > > > > >> > > > > > >> transitive dependencies > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> - module c depends on transformed classes in module b > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> What I would like the M2E extension to do, is on changed > > > > classes in > > > > > > > >> module a, transform these classes, write them in module b and > > > > > >> > > > > > >> refresh > > > > > >> > > > > > >> > > > > > >> > > > > > >> those classes, triggering a build in module c. This being my > > > > > >> first > > > > > >> > > > > > >> > > > > > >> > > > > > >> extension, I read the introduction on writing extensions and > > > > > > > > managed to > > > > > > > > > >> setup a project in Eclipse, but that's were it ends. All > > > > examples I > > > > > > > >> could find are about generating source from source, not > > > > classes from > > > > > > > >> classes. Is there an existing extension I could use as an > > > > > >> example? > > > > > >> > > > > > >> If > > > > > >> > > > > > >> > > > > > >> > > > > > >> not, what would be a good approach for this plugin? Which M2E > > > > > > > > classes do > > > > > > > > > >> I need to look at? > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> Best regards, > > > > > >> > > > > > >> > > > > > >> > > > > > >> Emond Papegaaij > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> _______________________________________________ > > > > > >> > > > > > >> > > > > > >> > > > > > >> m2e-users mailing list > > > > > >> > > > > > >> > > > > > >> > > > > > >> m2e-users@xxxxxxxxxxx > > > > > >> > > > > > >> > > > > > >> > > > > > >> https://dev.eclipse.org/mailman/listinfo/m2e-users > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> _______________________________________________ > > > > > > > > > > > > m2e-users mailing list > > > > > > > > > > > > > > > > > > > > > > > > m2e-users@xxxxxxxxxxx > > > > > > > > > > > > > > > > > > > > > > > > https://dev.eclipse.org/mailman/listinfo/m2e-users > > > > > > > > _______________________________________________ > > > > > > > > m2e-users mailing list > > > > > > > > m2e-users@xxxxxxxxxxx > > > > > > > > https://dev.eclipse.org/mailman/listinfo/m2e-users > > > > > > _______________________________________________ > > > > > > m2e-users mailing list > > > > > > m2e-users@xxxxxxxxxxx > > > > > > https://dev.eclipse.org/mailman/listinfo/m2e-users > > > > _______________________________________________ > > m2e-users mailing list > > m2e-users@xxxxxxxxxxx > > https://dev.eclipse.org/mailman/listinfo/m2e-users > > _______________________________________________ > m2e-users mailing list > m2e-users@xxxxxxxxxxx > https://dev.eclipse.org/mailman/listinfo/m2e-users
|