I am working on an RCP project based on eclipse. It has been working fine but recently I thought I'd upgrade it to use a new eclipse version (3.2 -> 3.5).
After a bit of trouble, it was running on the new platform. Then I did something. Don't know what. The end result is that I'm now getting a classpath error when one of my plugins (A) tries to access a class in one of the dependent plugins (B) (also one of mine).
As far as I can see, Plugin A has Plugin B in its' dependency list and the compiler shows no errors. To test, I created a new Plugin C with one class and accessed the class from Plugin A. That works fine.
Does anyone have any hints for troubleshooting such issues? A checklist of settings to check? I've been struggling with this for hours and getting nowhere! Particularly frustrating as it was working until I changed something!
Thanks
Update
I should also say that the project is quite old and uses the plugin.xml and not the manifest. Could this be a problem? Is there a way to upgrade?
Some ideas:
Clean-and-build every project (maybe after a restart of Eclipse)
Check, whether the required packages are also exported
Check the Error log, maybe there is some unloadable plug-in, etc.
Check the Run configuration, whether every required plug-in is present there
If the problem does not happen in a Runtime workbench, but in an Exported RCP app, then check whether you compile the project with the same settings during export than in Eclipse
I hope, something helps about these.
You can try the following in your run configuration:
In the Main tab check Clear (workspace) under Workspace Data
In the Configuration tab check clear the configuration area before launching under Configuration Area
This helps me every time I encounter some strange ClassNotFound errors.
If I understand you correctly you have no compiler errors but when you run you get class not found exceptions? You could try PDE Tools > Update Classpath from the project's context menu to see if you declared any dependencies outside of the MANIFEST.MF file, which would result in compiling code that fails at runtime.
I developed for RCP quite a long ago, but if I'm not wrong, since 3.4 or 3.5 you have to declare in the plugin configration which packages/classes are exported for dependent plugins and which are not.
This is unlike the old convention of using 'internal' in the package to mark non-exported packages.
Since you have plugin.xml from very old version of eclipse, it might be the problem, as exported resources from one plugin to another were not enforced in Eclipse RCP 3.2.
One more complement, hope it helps.
Open plugin.xml, check "build" tab, see how "binary build" are configured. It affects which files will compiled and exported.
See binary build here : http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.pde.doc.user%2Fguide%2Ftools%2Feditors%2Fmanifest_editor%2Fbuild.htm
Related
Introduction
I have spend a lot of time to fix this bug
In our application we have a lot of generated code by cxf and jaxb which produces tons of warnings. We use the maven-build-helper plugin to add this code to our projects automatically.
By adding this enhancement, eclipse JDT enabled the possibility to set the javac -nowarn flag for specific source folders. Unluckily, by updating the maven project the flag gets lost. There are a few threads on SO where users got bugged by bug.
What I have tried so far
So i came up with a clever solution, javac has a nowarn flag. I set it to my maven-compiler-plugin and specified the directory. My maven build was fine, but my eclipse build wasn't. My research told me, that eclipse jdt does only use the maven-compiler-plugin source and target version. So my next step was to try to configure the EclipseCompiler, but this is not possible, because there is no possibility to add custom compiler Arguments in eclipse JDT.
Next Step. Inside of the .classpath file, eclipse JDT adds an ignore_optional_problems attribute for each ignored path. By updating the maven project inside of eclipse, this entry gets lost. So i started to write a maven "ignore-source-folder" plugin which should add the missing attribute. To run the plugin each time eclipse starts a build, i also created a m2e connector to refresh the .classpath file and everything should be fine.
By testing my plugin with my connector i realized, it works, but only 70% of the repetitions.
What happened?
Every time eclipse m2e/Jdt starts a new build, all classpath entries will be removed and populated again. When my maven plugin gets triggered by eclipse, a race condition starts.
So I started to analyze the code of jdt and m2e jdt. The ignore_optional_problems flag gets only once set manually inside of the patch which was provided to JDT and isn't stored somewhere else. By triggering a new build via m2e-jdt this information gets lost.
How to fix this problem
To fix this problem, some element has to be added or extended in jdt which contains all ignored folders. If a new build gets triggered and the classpath file gets newly generated by m2e-jdt this element should be checked for ignored paths. ClasspathEntryDescriptor seems to be a good place for it.
My problem
I checked out jdt and m2e jdt, but i have tons of errors inside of my IDE and i have no idea how to start. And even if I fix the code, I have no idea how to build and test it. I think my effort will be to high and we talk about 20 or 30 simple lines of code.
I am afraid if I add my results to the filed bug at eclipse, no one will care about it.
So, is there any developer able and willing to help me for this tiny job?
You need to "fix" the M2E's JDT project configurator. Probably somewhere in the m2e-core project. So, your change should obtain some kind of configuration flag from the project pom and create corresponding classpath entries for JDT.
I'll try keep this short. I have Eclipse with an installed M2E (Maven to Eclipse) plugin. I have a GAE (Google App Engine) project I'm working on. Everything is working ok apart from one really annoying thing: I have to stop/start the devserver every time I make a change.
If you have any experience with this setup then you might be able to answer this simple question?
I start the development server with "mvn appegnine:devserver" on the command line. Now I would expect that if I made changes to a *.jsp for example that those changes would automatically be updated on the devserver. Is this what happens with you?
I have noticed that if I make changes to *.jsp files under my target folder then devserver will see those changes and updates as I would expect. I think my problem lies with Eclipse not copying changes to target folder, but not sure if is even suppose to?
Does anyone have any suggestions on how I should progress investigating this? I've ran out of ideas :-/
I thank you in advance for any comments you may have.
P.s I know I can run "mvn package" to update files, but this is slow and the devserver runs out of memory after a do it twice.
This can be little painful, depending on how you want to work and which version of eclipse you're using.
Install the m2e-wtp plugin if you haven't. It's the secret sauce that makes appengine projects work in eclipse. Note this isn't m2e - but another plugin.
Install the GPE - the google plugin for eclipse if you haven't
Make sure your project is being managed by m2e as a maven project.
Go into your project properties - enable it as an appengine project using the GPE (listed under 'Google'). Don't forget to tick HRD while you're here.
Go to your project build path (Properties -> Java Build Path).
Ensure on the source tab that your src/main/resources doesnt have an ** exclusion.
Ensure on the libraries tab your have the three libraries 'JDK', 'Google Appengine' and 'Maven Dependencies' and nothing else
Ensure on the order and export tab that the appengine dependencies are above the maven dependencies.
It sounds pretty ridiculous - i'm not really sure why its still so painful, but that is a good recipe for success. Once that's done, this should allow you to run in debug from eclipse itself, with hotloading of code, jsps, css, scripts etc. I've had this work in helios, indigo and juno.
You can read more about the m2e-wtp setup instructions here. They refer to GWT but it's the same for appengine (I'm not sure why the emphasis on using GWT on GAE) because its actually about the correct setup of GPE and Maven.
You will also find that you may need to repeat some parts of step 5 pretty frequently - if your app isn't loading properly take a quick look to ensure that your resources haven't been excluded. This happens when you update your project configuration using the m2e plugin.
The wtp-m2e plugin updates the target folder as resources modified - so this should also resolve your issues running from the command line, but i can't vouch for that - I prefer to run straight out of eclipse.
I have the same problem as you, however I resolved with other way. I use FileSync plugin (which can be found in the market place).
With this plugin you configure an input directory (webapp) and output directory (target).
Any change made to the webapp will be passed to the target.
I have helped too.
You can use rsync like this:
rsync -r --existing src/main/webapp/ target/ROOT
where "ROOT" is the project build finalName.
The below point worked for me.
Ensure on the order and export tab that the appengine dependencies are above the maven dependencies.
Background
I'm currently trying to extend Junit (org.eclipse.jdt) in order to do some tracing.
Therefore I created my own plugin project which (among others) provides a class which should be used by the junit runtime plugin.
I have setup my project as a dependency for junit and the package containing my class is listed as "exported" in my Manifest in the runtime tab. If I run the plugins as an eclipse application everything builds and starts allright and.
Problem
However, if in the started eclipse I perform a "Run as Junit", I get a NoClassDefFoundError concerning my class. In my understanding this means, that at runtime my class is not visible in the started eclipse. I thus printed the classpath while running and like expected my plugin doesn't show up.
Do I have to add my plugin to the "runtime" settings of the junit plugin? In the Manifest, my package is not available under the "export -> add" button. I tried importing a jar of my plugin and configuring those exports manually here, but this did not help either.
My thought process kind of gets stuck with this "run in run" configuration...
Any help is welcome!
Digging deeper in the code I found that the reason for the error is, that the part which calls my code and throws the error is run in a seperately started VM which has its classpath set via code. Nothing was wrong with the configuration, it just was not used in this case.
So if you ever stumble upon a "VMRunnerConfiguration" while having classpath problems, this might be your problem. ;)
I've written an Eclipse RCP application that runs fine in Eclipse, however, packaging it to be a standalone application has been tricky. I've worked my way though a few class path errors, but now I'm getting a new one.
After running the export wizard and launching my application, it throws a ClassDefError and ClassNotFoundException, specifically it's looking for org.eclipse.ui.plugin.AbstractUIPlugin. I did not find this in my copy of the eclipse SDK, and I downloaded the SDK again to be sure, and still couldn't find it. I found a jar online that supposedly contained the fiel along with some other eclipse packages, however, I then got this:
NoSuchMethodError: org.eclipse.ui.plugin.AbstractUIPlugin: method ()V not found
I figure the problem is more I did something wrong rather than this class is actually missing, but I've gone though all the configurations and I'm sure all the required packages and dependencies are included. Any ideas?
Download and install the new version of adt plugin 21.0.0.
Does your application works when you run from Eclipse? If so then try to open your plugin.xml, go to Runtime and on the bottom right part of the window you should see Classpath. Try adding the required plugins there.
I downloaded the source code for the EMF based UML2 Plugin and changed a class in the org.eclipse.uml2.uml.edit project to remove special characters when returning string representations. Now when I export the projects and place the jar files either in the dropins directory or replace my current uml2 plugin jar files in plugins directory, The UML files are no longer recognized, in short my modified plugin does not install correctly (no error is thrown and I can see the files being picked up under Plugins->Target Platform) .
However, When I run the plugin as an eclipse application (from the workspace) I can see the changes I made being reflected in the new instance of eclipse.
What can I do to ensure that the plugin installs correctly?
Is there a documented procedure of how to build the uml2 plugin (or any comparable plugin) after modification?
Select the project and open the context menu. There is an entry PDE near the bottom of the menu. In there, you can find an entry to build the plugin for deployment. This gives you the features and plugins directory with the fixed files. Copy both into your Eclipse install.
Unless the UML2 plugins require some kind of magic build script, exporting the one plugin you changed and overwriting the original in your Eclipse installation should be the easiest solution. One potential problem which comes to mind is conflicting plugin version numbers: make sure you don't have two identical versions of your modified plugin in your Eclipse installation.
When debugging plugins which apparently don't work properly at runtime, I always look at Help > About Eclipse Platform > Configuration Details. This lists all the plugins found by Equinox during startup, along with their status (see the Javadoc of the org.osgi.framework.Bundle interface for explanation).
I faced the exact same problem as you describe here . I dont have any answer to your problem but i am sharing what worked for me .
I created a local update site of the plugin on my system. Create update site for your plug-in article explains very very nicely the steps needed to accomplish this .