Eclipse Debugger: Source not found for project references - eclipse

I am seeing a problem whereby the Eclipse Debugger cannot find the source for classes that are included as project references.
My application contains 2 types of referenced libraries: those in the Maven repository, and those that are included as part of a project reference to another project in my workspace.
The debugger has no issue showing source for any classes in the Maven repository.
However, when it tries to debug classes included using a project reference then it cannot find the source. Even when I click on the "Edit Source Lookup Path" and specify the location of the project it cannot find the source. I have confirmed that the class in question does exist in the project's output folder so I'm not sure what the problem is here.
Can someone please help?
Thanks

OK, I've resolved this almost as quick as I opened it.
The problem seems to have been caused by the way I was importing my application's project.
So in Eclipse, I imported this using m2e's File > Import > maven > Existing Maven Projects.
This resulted in dependencies that existed in my workspace being included as project references instead of actual jar file references to the Maven repository.
To get the actual jar file references to the Maven repository, I ran mvn eclipse:eclipse and my debugger was able to pick up the source code.
Is this a known problem with the m2e plugin?

Related

Importing multimodule maven project from Git into Eclipse/STS

I have been desperately trying to import a multimodule maven project from GIT into my (freshly installed) STS 3.9.4.
During the last hours I tried lots of solutions that were posted on stack overflow, but none of them worked for me.
These are the steps I did:
git cloned the repo from the command line (intentionally, because it didn't work either when I used the GIT integration of STS)
imported the project via File / Import / Maven / Existing Maven Projects
After the project was imported, it looks like this:
(please ignore the red icon at the top left, the problems persists even when this icon is not there)
I can Run As / Maven Install any pom.xml, but when I try to edit java sourcecode Eclipse tells me The resource is not on the build path of a Java project.
To fix this I tried:
convert to faceted form
added Java nature
Configure Build Path / Set as source folder
add buildcommand org.eclipse.jdt.core.javabuilder to .project
Being able to build is fine, but editing sourcecode without support for Organize Imports, Format Source, and so on is a real pain.
From your screenshot I assume the modules are nested within the directory of the reactor pom(=parent pom) and you have imported all of them as projects (reactor and modules).
Don't add a java builder to the "reactor" project.
Make sure not to open the java files from the projects corresponding to the reactor pom, but from src folder within the corresponding module projects.
The solution to this problem was somehow hidden, but in the end I have to say the reason was clear.
After I checked with a different multimodule project (https://github.com/Activiti/Activiti.git), I was sure that my STS and other components don't suffer from a generic problem. So the cause must be located in the project itself.
The multimodule project was setup correctly on the pom.xml level. But the topmost pom.xml was modified: most of the modules had been commented out:
The developer who introduced that change didn't experience any problems because he kept his already existing workspace. And the problem only occurs when a new workspace gets created and maven scans the pom files.

m2e (eclipse) Throwing error after converting to a maven project

I'm trying to convert an eclipse Java project to a Maven project. When I convert the project to a Maven project, the pom.xml displays the following error:
Cannot read lifecycle mapping metadata for artifact
org.apache.maven.plugins:maven-jar-plugin:maven-plugin:2.3.2:runtime
Cause: error in opening zip file
When I check the lifecycle file, it's blank. Any idea of why I can't convert this project without getting this error?
Thanks for the assistance!
If that file is empty, it might have been caused by a bad download of the maven artifact. Therefore check your proxy settings in Eclipse as well as in Maven itself (~/.m2/settings.xml)
One thing you can try is deleting the project(from the workspace, not from your computer!) and importing it as a maven project using the deleted project's folder as your source. I've had a lot of trouble in the past with converting projects with m2e, but deleting/re-importing always seems to do the trick.
To import an existing project as a maven project go to file->import and select "Existing Maven Project". Select your project's folder, and import. I realize it's basically the equivalent of "turn it off and turn it on again", but like I said, it has always worked for me in the past. At the very least it will help you narrow your scope.
Hope this helps!

Maven in eclipse not showing all folders

I am new to Maven and have been trying to get a project working with Eclipse, hibernate,Maven and mysql. I am stuck at the very first step. I have everything configured properly i think and if i create a new Maven project in eclipse it does not show me any folder under src/main or src/test. although if i go back to that folder in the workspace it has a src/main/java
FUrthermore the src/main/resources folder is not created at the time of project creation?
Any clue what the problem maybe or how i can fix it?
Thank you!
For your first problem, when you create a new Maven project the folders that get created depend on the archetype you choose. Assuming you chose quickstart, then it does create (assuming you chose com.example as your package in the wizard and example-project as your artifactId):
And it configures the project so that /src/main/java is in the Build Path. That said, if you are viewing your project in the Package Explorer view, then the packages are shown outside of the folder structure. So, you would see the the com.example.example_project package containing App.java in the build folder /src/main/java and you would see the com.example.example_project package containing AppTest.java in the build folder /src/test/java. These would show up above the libraries which is above non-build folders which is where you see the src folder.
To answer your second question, no, /src/main/resources is not generated assuming you chose the quickstart archetype (this is governed by the quickstart archetype and does the same thing whether generated in eclipse or on the command line).
And third, to fix this (I assume you mean add the resources folder), find the src/java folder (below the libraries), right click and choose New->Folder. Name it resources. Then right click your project, choose Maven->Update Project. This will cause maven eclipse to reconfigure the project according to the Maven configuration which will result in the /src/main/resources being added to the build path. As such, it will get moved above the libraries next to /src/main/java and /src/test/java.

Errors in exporting eclipse deployable plug-ins and fragments

I have an eclipse plug-in working fine within eclipse environment.
I wanted to export it into a jar file, so I chose Export > Deployable plug-ins and fragments.
I could get a jar file, but an error was reported.
Opening the log file, it reports that I have 1242 problems (191 errors, 1051 warnings). This is some copy from the error log.
2. ERROR in /Users/LSclipse/src/lsclipse/LSDiffRunner.java (at line 61)
import edu.washington.cs.induction.OnePipeLineScript;
^^^
The import edu cannot be resolved
----------
3. ERROR in /Users/LSclipse/src/lsclipse/LSDiffRunner.java (at line 261)
OnePipeLineScript.getMatchingForRefFinder(projName, proj1, proj1Loc
^^^^^^^^^^^^^^^^^
OnePipeLineScript cannot be resolved
Why I got errors? I had 2049 warnings, but no error when I compile the plugin in eclipse IDE.
ADDED
The main project references two other projects, and references many external libraries. I attach the package view and Java build path.
There were multiple issues involved for this problem. However, the core issue was that the project apimatching and originanalysis were not eclipse plugins but just java projects. As a result, those two projects were not included in the final jar file to break the build.
Symbolic linking the two projects into the main project
I solved this issue by symbolic link the src directory into the main eclipse plugin project.
ln -s /workspace/seal/edu.ucsc.originanalysis/src /LSclipse/originanalysis
ln -s /workspace/seal/edu.ucsc.apimatching/src /LSclipse/apimatching
From the Java Build Path/Source tab, I added those two included projects as source. Eclipse Java Missing required source folder: 'src'
Now I have eclipse plugin jar file without error.
Then click F-5 to refresh the project explorer and check they are java src directory.
Select the included projects in Build tab.
Updating bin.include and source.. in build.properties tab is important. One should understand that in bin.include the ordering is also critical. lib/cdtparser.jar and lib/cdtcore.jar should be placed prior to the user of them - origin analysis/.
Copying jar files for included project into main project
I also had to copy some jar files in those projects file into the main project, and select them in Binary Build tab.
And add tim in Runtime/Classpath tab.
Select the JavaSE-1.6 in Execution Environments.
I have lots of "Must Override a Superclass Method" errors. With the hint from this post - 'Must Override a Superclass Method' Errors after importing a project into Eclipse , I removed the J2SE-1.5 to resolve this issue.
You can not add third party libraries into class path of Java when developing a plug-in. It is the way to build standard Java application, but plug-in is a kind of OSGi bundle that has itself rule for class loading.
The correct way is adding third party libraries into the class path of your plug-in.
Add below declaration into MANIFEST.MF of your plug-in,
Bundle-ClassPath: lib/log4j-1.2.7.jar,
xml-apis.jar,
...
Check those links [1], [2] for understanding it.
This is what have a question on and see as potential solutions to potential problems.
Is this class comfing from a referenced jar or is it in the actual plugin edu.washington.cs.induction.OnePipeLineScript;
You seem to have a lot of soure folders and wondering if your build.properties file is showing any warnings and that you also have this defined for each of the source folders in your build.properties source.. = src/
Your external jar libraries appear to be in a folder that is of type source which is not correct. It should be a non-source folder (which you can tell a source folder by the package icon decorator) and you should make sure in your manifest editor that for runtime you have the lib checked so that it includes the jars in the build. To unmark it as a source folder select the drop down menu in your navigator view go to filters and uncheck .resources which will then show the .classpath file in that file you will see the folder to be kind="src" (i believe) remove that.
Somehow it also looks like you have linked source folders which is a practice I would not suggest and am not sure if that will cause problems when exporting the plugin. If you can avoid linked source folders that would be better.
Also it seems like you are confusing java build path configuration for plain java applications with plugins running in OSGI which is not configured through java build path but your manifest.editor So as a rule of thumb if its a plugin don't even bother trying to configure the java build path because OSGI is different, that could be causing issues as well
Select "Use class files complied in the workspace" in Options works for me.

How to get peer project source in eclipse and maven

creating a parent project with only a pom.xml, and lots of sub projects such as:
my-web
my-core
my-backoffice
etc. is easy, and the sonotype eclipse plugin does most of the work.
However, getting one project to know about the source in the other project seems to be hard. E.g. when you are debugging the my-web project, and step into my-core, eclipse doesnt know where to get the source.
Looking in the Java Build Path in eclipse, the maven plugin has added my-core as a folder under "Web App Libraries". I.e. its not using the my-core-0.0.1.SNAPSHOT.jar or similar, its using the raw java files. Great!
But how to tell maven to tell eclipse to look for the source in the same place?
Im not really sure where to start. Im guessing its possible to get maven to put the source in a special jar using the maven-soure-plugin, but this will usually be out of sync with the actual java files which the web project seems to be using directly.
A quick and dirty solution is to manually Edit the Java Build Path for each project, and add my-core and other dependant projects in the "Projects" tab. Is this best practice? Any other suggestions?
A quick and dirty solution is to
manually Edit the Java Build Path for
each project, and add my-core and
other dependant projects in the
"Projects" tab.
If this doesn't happen automatically you have a configuration problem.
My Guess would be that you have a version mismatch between the pom dependencies and the actual project versions. Or your projects have an unusual name template (m2eclipse resolves projects by their artifactId AFAIK)
Either way, what always helps is in your Debug configuration (Run > Debug Configurations ...) select the Source tab and just Add... the selected projects.