m2eclipse not finding maven dependencies, artifacts not found

Question

I'm using m2eclipse as my maven 2 plugin for eclipse. I'm brand new to maven, so my mistake might be simple, although searching has not yielded any solutions for me. I can run maven from the command line and it build successfully. However if I import as an existing maven project, or use mvn eclipse:eclipse and then import I get the artifacts not found in my POM file resulting in no maven dependencies being loaded at all.

What's odd is that I have 2 projects, both children to a parent pom packaged project. One child loads all my maven dependencies while the other cannot find any and says my pom file is missing artifacts. Again, I can install and package them all just fine from the command line.

I even tried loading my projects into netbeans which worked flawlessly, however I am required to use eclipse.

Any ideas on how to fix this?

Update

Directory structure, pom files layout:

--main
  --pom.xml   (is a pom package that is the parent to two other projects)
  --ProjectA
    --pom.xml
  --ProjectB
    --pom.xml

Main is the parent project of both ProjectA and ProjectB. ProjectB has ProjectA as a dependency. Apprently m2eclipse is not happy about that depedency. As soon as I remove the dependency of ProjectA from ProjectB's pom file all the maven dependencies are found by eclipse.

- com.company.myproj:app:6.6.0:jar Missing: ---------- 1) com.company.myproj:main:pom:${myproj.version} ---------- 1 required artifact is missing. for artifact: com.company.myproj:main:pom:$
 {myproj.version} from the specified remote repositories: apache-incubating (http://people.apache.org/repo/m2-incubating-repository/, releases=true, snapshots=true), central (http://
 repo1.maven.org/maven2, releases=true, snapshots=false)

However, I still need ProjectB to have that dependency for ProjectA. The error message seems to be m2eclipse looking for ProjectA in a remote repo. Project A should only be in .m2 directory, but I'm not sure how to tell m2eclipse to look there.

I think this may be just a m2eclipse specific issue because using mvn from the command line works fine and like I said previously, netbeans loads the projects and dependencies just fine.

Answer 1

I had this issue for dependencies that were created in other projects. Downloaded thirdparty dependencies showed up fine in the build path, but not a library that I had created.

SOLUTION: In the project that is not building correctly, right-click on the project and choose Properties, and then Maven. Uncheck the box labeled "Resolve dependencies from Workspace projects", hit Apply, and then OK. Right-click again on your project and do a Maven->Update Snapshots (or Update Dependencies) and your errors should go away when your project rebuilds (automatically if you have auto-build enabled).

Answer 2

It sounds like your m2eclipse install is using the embedded Maven, which has its own repository (located under user home) and settings.

If you open up the Maven preferences (Window->Preferences->Maven->Installations, you can add your Maven installation by selecting Add... then browsing to the M2_HOME directory.

_{(source: sonatype.com)}

For more details see the m2eclipse book

Answer 3

For me maven was downloading the dependency but was unable to add it to the classpath. I saw my .classpath of the project,it didnt have any maven-related entry. When I added

<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER"/>

the issue got resolved for me.

Answer 4

One of the reason I found was why it doesn't find a jar from repository might be because the .pom file for that particular jar might be missing or corrupt. Just correct it and try to load from local repository.

Answer 5

Okay I fixed this thing. Had to first convert the projects to Maven Projects, then remove them from the Eclipse workspace, and then re-import them.

Answer 6

I had problems with using m2eclipse (i.e. it did not appear to be installed at all) but I develop a project using IAM - maven plugin for eclipse supported by Eclipse Foundation (or hosted or something like that).

I had sometimes problems as sometimes some strange error appeared for project (it couldn't move something) but simple command (run from eclipse as task or from console) + refresh (F5) solved all problems:

mvn clean

However please note that I created project in eclipse. However I modified pom.xml by hand.

Answer 7

This could be a problem if you are using a custom 'Settings.xml', with a different <localRepository> configured in it.

Eclipse will be using the default installation of MAVEN, and will be using the default location for the User to look for the local Maven repository, which on Linux systems would be '/home/${USER}/.m2/'

Eclipse can be easily configured to use the customized 'Settings.xml', by doing the following: Goto -> Window -> Preferences -> Select 'Maven' -> Select 'User Settings'

1. Under 'User Settings', select the custom 'Settings.xml' file, for 'User Settings' by clicking 'Browse' and selecting the customized 'Settings.xml'.
2. Click on 'Update Settings', if the 'Local Repository' Textbox does not show the custom location from the file above, just key in the location and click 'Reindex'.
3. Click 'OK'

After this, you could proceed to select your project from the 'Project Explorer', right click, Select 'Maven' > 'Update Project'. Make sure that your project is selected (ticked) in the Window, and click 'OK'.

This should help to resolve the issue, if using custom 'Settings.xml' for Maven.

Hope it helps.