I've got several projects in Eclipse (all are Maven projects) and one main project (also Maven project) which depends on the rest. I tried add this dependency by setting java build path (right click on project -> preferences -> java build path -> (tab) projects -> add). But there is a problem while executing maven install goal - this is compilation error: ... (class) ... "cannot be resolved" ... - this is definitely looks like maven does't see my resources from other projects. Eclipse is only warning me something like this: "Classpath entry /my-subproject1 will not be exported or published. Runtime ClassNotFoundExceptions may result." These warnings referenced to each subproject and occurs in main project. There is no error messages from Eclipse. In my main project, where I'm importing classes from subprojects, I can right-click on one of the import and choose "Open declaration" and there is valid reference to class from one of my subproject - so it looks like Eclipse sees my dependencies (there is no eclipse errors while building workspace - only these warnings mentioned above) from other projects, but maven doesn't see them while compilation.
Have you got any ideas how can I fix this?
Thanks for help.
You have to declare your dependencies in the pom.xml for Maven. Maven doesn't recognize any Eclipse specific configurations (like Build Path etc.): Maven Tutorial
If you use the m2eclipse plugin, it will configure your Eclipse build path according to your pom.xml configuration
Isn't this maven problem?
Maven needs jar file made from other project inside maven repository.
I don't know much about maven eclipse plugin but so far, in my observation, it seems like it works this way.
So that this case need to build other project so that create it's jar file.
But this takes so much time.
Related
I have a maven project that uses other small projects. And I added them to master's pom file.
So my Eclipse project properties looks like following:
>Master project
>Java Resources
>Libraries
>JRE System Library
>Maven dependencies
>smallProj1.jar
>smallProj2.jar
The thing is I do not have the all code for smallProj1 and smallProj2 and whenever add them to my workspace Eclipse overrides the maven dependencies and simply calls the two projects instead the jar files from my local maven repository and then I have all over the code those red underlines. Project properties in Eclipse looks as following after I add them to my workspace:
>Master project
>smallProj1
>smallProj2
>Java Resources
>Libraries
>JRE System Library
>Maven dependencies
>smallProj1 (not jar anymore - folder)
>smallProj2 (not jar anymore - folder)
Since I also want to have a look to smallProj1 and smallProj2 code while I am coding, I want to keep them both in my workspace. But I want my Master project to use the jar files that I provided, not the small projects in the workspace.
Any ideas on that?
You could right click on a project and set "Maven" -> "Disable Workspace Resolution". This will let Maven find the dependencies from Maven and not within the workspace. I don't think it is possible to do this on a dependency basis.
But I think in your case it would be better to fix the broken smallProjX in your workspace (as they exactly contain the code you need), so that the master project could be build correctly.
I have a maven project that depends on a jar (say A). When running the project, it uses the jar under Maven dependencies.
I have the source of A with me and its opened as a project in Eclipse. When I run the project I need to use the source and not the jar. How do I tell Eclipse to use the source and not the jar?
m2eclipse does this by default, if that is a full Maven project. See the context menu in the screen shot of http://www.sonatype.com/books/m2eclipse-book/reference/eclipse.html#eclipse-sect-resolving-dependencies, where it says "Disable workspace resolution".
If you don't find that context menu entry for your project, then you probably have a Java project with a POM file, which is not marked as Maven project type in Eclipse. Use the context menu Configure->Convert to Maven project in that case.
I had problems with the workspace resolution of m2eclipse as well. It would recognize the dependency (A) and show a different icon in the dependency view (which indicates that the dependency is resolved from the workspace) but the classes were not found.
Only when I ran a mvn install on project A all artifacts were generated and the resolution started to work. Maybe that helps.
Also I found a couple of hints (related to not working workspace resulotion) that suggested to (re-)import the project again using "Existing Maven Projects" wizard.
I have multiple related projects open in a workspace in eclipse. One of the projects has a maven dependency on the output jar from another project. In this project, any references to the classes in the dependency always show up as red (unidentified) and I get no code completion or javadoc showing up for them. If I manually add the jar to the classpath, then I no longer have this problem. The thing is, I don't want to have to manually add the jar every time our revision changes, that's what Maven is for. Any ideas on how I can resolve this? it seems like a bug to me, but I'm not sure...
The correct way to do this is the following:
Make sure that m2e or m2eclipse (depending on your version of Eclipse) is installed: http://www.eclipse.org/m2e/
Use the dependencies section in the POM file exclusively, don't fiddle with the Eclipse project references. Right-click the project, then select Maven > Update Project Configuration to reset the project to the Maven default settings. This way, m2e has ownership of the dependencies.
If you don't have that option, you might need to enable the project for Maven usage. Right-click the project, then Maven > Enable Workspace Resolution or Maven > Enable Dependency Management.
Make sure all referenced projects are open in Eclipse and have the Maven nature enabled.
Check the Maven settings for each project, make sure that groupId, artifactId and version match with the projects you have open in Eclipse. So if the project you depend on has version 1.0.0-SNAPSHOT in Eclipse, make sure that the depending project's POM file references version 1.0.0-SNAPSHOT in the dependencies section.
Enable Workspace Resolution for each of the projects. Right-click the project, then Maven > Enable Workspace Resolution.
Finally, if the projects are still not resolved, right-click the project again, then Maven > Update Dependencies
This should solve your problem.
I had the same issue and resolved the problem by right-clicking on the project and selecting Maven -> Disable Workspace Resolution from the context menu. I had already tried updating the project from the POM file as described above.
In order to fix this typically you can copy the Eclipse .classpath file from a working project since there isn’t anything project specific here assuming you’re structured as a standard Maven project. This will tell Eclipse to allow Maven to manage the dependencies and build. There seems to be no easy way to do this from the Eclipse UI.
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.
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).
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
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.
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.
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.
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.
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'
Under 'User Settings', select the custom 'Settings.xml' file, for 'User Settings' by clicking 'Browse' and selecting the customized 'Settings.xml'.
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'.
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.
I'm having maven project on Eclipse with m2eclipse plugin. This project has some dependencies. Some of them are libraries as slf4j, apache-commons etc. But there are also mine libraries, that I'm developing simultaneously in eclipse. Unfortunately m2eclipse creates build path in such a way that my libraries are added to the classpath not as a JAR archives from M2 repository but as class files from /target/classes directory. For that reason I can not use maven-shade-plugin beacuse I'm gettin a message:
" Error creating shaded jar: error in opening zip file /home/user/workspace/my-project/project-a/target/classes".
When I'm building project-a from command line using mvn clean install everything works well - shaded JAR is generated. How to fix it?
After few hours of searching I've already found solution. This can be made by configurinng Maven Build Configuration
1. Select arrow on Run as.. button
2. Select Run configurations...
3. Select yours project Maven Builder
4. On the right tab (Main tab) deselect: Resolve Workspace artifacts.
Click Apply and build your project - all will work as you wish :).