maven project in eclipse keeps normal package structure - eclipse

I am trying to import a maven project (import->existing maven project) into eclipse and it is showing up in eclipse using the generic java project structure as opposed to the maven one. I have tried several versions of the m2e connection and all have the same problem. So for example instead of the following folders/packages/files I have:
src/
main.java.my.package.name
myfile.java
test.java.my.package.name
testfile.java
etc.
instead of the maven project structure
src/main/java
my.package.name
myfile.java
etc.
Any assistance appreciated, thanks!

For the sake of completeness:
This happens sometimes due to a race condition in eclipse.
As you already found out: if it happens, it happens only once, on initial import. So your way was almost correct:
Remove all source paths
do not add them manually
instead, right-click on the project and select "Maven -> Update project" and accept the default settings. Now the source paths will be set correctly

Woops, right after posting I was able to get it to work.
I had to go to project -> build path -> Source and remove the src/ folder and add the src/main/java, src/main/resources, etc. folders and it all works now.
Thanks for looking y'all!

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.

How do I get my Eclipse-Maven project to automatically update its classpath when I change a dependency in my pom.xml file?

I’m using Eclipse Mars with Maven (v 3.3). When I update a dependency in my pom (change the version), my Eclipse-Maven project doesn’t pick it up, even when I right click my project, and select “Maven” -> “Update Project.” I know this because I do not see compilation errors in the Eclipse Java editor that I see when I build the project on the command line using
mvn clean install
When I remove the project from the workspace and re-import it, then things get back to normal. However this is a cumbersome process. How do I get my Maven-Eclipse project to automatically detect changes in my pom and update the project libraries appropriately?
And yes, in the “Project” menu, “Build Automatically” is checked.
When you import the project into Eclipse, use Eclipse's own built-in Maven support (aka, m2e). I recommend against using mvn eclipse:eclipse as it doesn't give the best results (as you're seeing). Maven is a build and dependency management tool, not an IDE; expecting it to manage IDE-specific stuff is silly, in my opinion (I realize the Maven team thinks differently, that Maven should be responsible for managing your IDE, but that's nonsense).
So if you have the project available on your system, delete any Eclipse-specific files (typically just .classpath, .project, and folder .settings), they were generated by mvn eclipse:eclipse and you don't want them interfering with the "proper" import process described here. Then inside Eclipse, use File > Import > Maven > Existing Maven Projects to import the project. That should result in better integration between Eclipse and maven, including automatically updating the Eclipse build path when the pom is changed.
As a quick check, after doing the import that way, you should see a group called Maven Dependencies in the Libraries tab of the project's Build Path (in Properties dialog). Like this:
If you want the Eclipse project configuration to be automatically updated every time the pom is changed, there's a (experimental) setting for that under Preferences > Maven. Be aware that doing so might not be desirable, though - as mentioned in this feature request, it's a somewhat lengthy process that touches a bunch of stuff in the Eclipse Project; doing that automatically on every pom.xml change could end up being more trouble than it's worth.
Three Mandatory checks you should do for automatic update in your classpath
Your Repository is not in-sync with your Eclipse IDE, Please check the below settings in your IDE.
Right Click your any POM.xml from your IDE and check for the Maven profile which should be auto-activated. Also offline and Force update check box shouldn't be enabled. Please refer the below image.
Always check for your user settings which should reflect your local maven settings.xml, as shown in the below figure.
After performing all these checks, refresh your Eclipse Work-space to get these changes reflected.
Eclipse should be updating your classpath. If it's not, that implies something is going wrong.
It's hard to say what the problem could be exactly without knowing more about your project's pom.xml. More information might be necessary to solve the issue, but I'll just make a stab in the dark:
Open the .project file in your project's root folder and check the ordering of builders and natures there. It might be possible that some other nature on the project is also causing maven2Nature to fail. Move maven nature up and see if that helps any.
Alternatively you might be thinking that Eclipse does not update your dependencies because it does not add some some error indicators in the project that should be there with new dependencies. If that's the case try cleaning the current project (project>clean...). Maven in Eclipse does not necessarily trigger a full rebuild when dependencies are updated.
If none of this works, closing/opening the project might solve the issue quicker than re-importing.
What you wrote, should work. Did you check this:
does "pure" mvn install from terminal see your changes in POM?
maybe some Maybe plugin is buggy, cached some dependencies in target, and mvn clean install is needed
you can run Eclipse in a new workspace, and import your project there, sometimes it helps in case of such strange problems
instead of importing Maven project to Eclipse via m2eclipse, you can try to create Eclipse files via the old mvn eclipse:eclipse and see what happens then
does it work well when you try to import your Maven project to other IDE, the free IntelliJ Community Edition for example?
As a last resort, you can delete your current Eclipse installation and install a new version. When you add several plugins, they might interfere with one another and create weird behavior. After you do that, do not import your Maven project into your workspace, but rather create a new one and copy and paste the files that you had.

pom.xml greyed out when importing maven project into eclipse

In eclipse Mars, I could always clone a git repository and then import it as a maven project. But this time, the pom.xml is greyed out. On the next screen only the pom of another project is showing and I can't proceed.
Are you sure you have not already imported the project into the workspace? Maybe you just don't see it. One reason can be that you are using working sets and the project is not in the group you'd expect it to be in?
If the project is already imported into your workspace, and you are trying to import another copy of the same project that resides in a different folder, you can try adding some string for Name Template under Advanced and the importing.

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.

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.