Getting m2eclipse to match maven's classpath - java

I've got project with a few sub modules.
mvn clean install
works absolutely fine. But in Eclipse with the parent project open none of the maven dependencies are available and so all my Java source files are full of indicated compilation errors (they're not listed in the build path for the project). If I open one of the sub modules as a project there are no indicated compilation problems.
I've tried running
mvn clean install eclipse:clean eclipse:m2eclipsemvn clean install eclipse:clean eclipse:m2eclipse
and choosing project / update maven dependencies. Refreshing, closing and opening the project and Eclipse, etc.
Any ideas? Thanks in advance.

Getting m2eclipse to match maven's classpath
Just use Import... > Existing Maven Projects and import your multi-modules Maven project, that's all.
But in Eclipse with the parent project open none of the maven dependencies are available and so all my Java source files are full of indicated compilation errors (they're not listed in the build path for the project).
A parent project (i.e. with a pom packaging) is not a Java project, it's just there as a facility to make editing the parent pom.xml from the IDE possible (and that's already nice, importing nested projects inside Eclipse was initially not even possible).
If I open one of the sub modules as a project there are no indicated compilation problems.
That's how you are supposed to do things.
I've tried running (...)
You are not supposed to use the Maven Eclipse Plugin when using m2eclipse and this is not supported. Either use one or the other. If you decide to use m2eclipse, use Import... > Existing Maven Projects as suggested.

Related

Building an artifact from a modified maven project with Intellij

i am trying to build an artifact from a modified maven project imported in intellij (v2016.2).
Have managed to:
(1) Import/build a multi module maven project in intellij
(2) Successfully built/run an artifact as a single jar from the project
(3) Modified maven project by writing new classes with extra depedencies (via changing project's structure and adding new maven dependencies*)
(4) Successfully built & run modified project
however, when i try to run an artifact from the modified project (and even if it contains all the dependencies in the jar), it completely ignores all the extra functionality of the modified project (runs exactly as in (2))
What am I missing?
*note: havent touched any poms till now. All the dependencies added using File>Project Structure>Modules>Dependencies>add Library ...
If you don't see any change when running the project it's because you run the the previous build.
"Add Library" won't update your pom.xml. (Add maven dependency... will do)
To fix your maven project, you need to edit the pom.xml by hand to add the new libraries. (section dependencies)
Once it's done run mvn clean build from command line or from the maven project window (on the right edge of IntelliJ window).

Eclipse fix project setup by updating pom?

In an eclipse project, I referenced a class that was currently not in project's build path.
In the context sensitive pop-up that opens by hovering the mouse over the error, "Fix project setup" option has offered me to add a jar to the build path of the project. This jar is in my local maven repository.
However, the "correct" way to fix it is obviously by adding the relevant dependencies to my project's pom, instead of adding this jar to the build path of the project.
So is there a way to configure eclipse, so that it won't offer to add a maven repo jar to the build path, but it will offer to fix the project's pom?
This feature used to exist in m2eclipse (the predecessor of m2e), see e.g.
https://blog.sonatype.com/2010/03/adding-dependencies-using-m2eclipse/ which shows a "Search dependency for XXX" quickfix above the "Fix project setup..." quickfix.
Unfortunately it didn't make it into m2e, see https://www.eclipse.org/lists/m2e-users/msg01130.html
Make sure:
your project is fine outside of eclipse using only maven/pom, mvn
clean install (or similar) in an external shell/console
your eclipse project has maven nature
Eclipse -> Project -> Build Automatically is checked
Refresh your eclipse project
Do something in the pom.xml (save file) should trigger a build

Missing Java Build Path for Maven project

So I recently imported a project from Github into Eclipse and converted it to a Maven Project. However, when I try to add Libraries, the "Java Build Path" menu is missing from Properties. What's the issue and how can I fix it?
Generally you don't have to manipulate your build path entry manually when your project has the Maven nature, because that is already whay Maven is intended to do: "Manage your project dependencies" which means grabbing the needed versions, saving them into your local repository then use those downloaded artifacts in your project classpath when you run one of the mvn goals (depending on the dependencies scopes).

Errors after importing Maven project into Eclipse

I imported a Maven project into Eclipse. I was able to deploy it from the command line. In Eclipse it is full of red Xs. I have cleaned the project, updated the configuration and I ran the following command:
mvn -Declipse.workspace=<pathtoworksapce> eclipse:add-maven-repo
and I still have the same problem. The project is dependent on another project.
What I ended up doing was removing all of the projects in Eclipse, but not deleting the source files. Then instead of directly importing the code as Maven->Check out as Maven Projects with SCM, I selected Existing Maven Project and imported the code from my local machine. This got rid of the errors, but when I would right click on code and select "Open Declaration", I would get Error: Could not open the editor: The file does not exist" So I removed all projects again and this time I deleted all the ".project" files and repeated the import Existing Maven Project. So now there are no red Xs (dependency problems) and the lookup functionality within the code works.
Go to your master project and type the following :
mvn install
mvn eclipse:eclipse
After that, import your project. You can also install m2eclipse for better support. If you use gwt or any other framework which has a custom maven execution, you should also install plugins for those in Eclipse.

In eclipse, maven dependencies are overriding project dependencies

I have a "master project" that uses several "modules". The modules are in the pom.xml, but I also have the code for the modules as projects in Eclipse. I defined the modules as project dependencies both in "Properties|Project References" and in "Properties|Java Build Path". I also made sure all of the Eclipse projects are at the top of "Order and Export" in Java Build Path.
The master project is not recognizing changes to the modules within eclipse. When I press F3 to see the code, it opens java source from my .m2 directory. It's obviously ignoring my Eclipse projects. Am I missing some setting? What should I do?
You don't need to add the dependent projects into the Project references (at least when using m2eclipse-plugin), just add them as dependencies on your masters' pom.xml. I haven't had the need to touch the Build path since I've started using Maven in Eclipse.
Make sure you have enabled the Workspace resolution of the plugin by right clicking on project root -> Maven -> Enable Workspace Resolution. If it says "Disable Workspace Resolution", it is already enabled. You may also need to run "Update project configuration" under the same menu.
This way when you run your master-project from within Eclipse, any changes made to the other projects will be "visible" to the master (and you can actually use hot swap during runtime even on the other projects).
If you're using Maven, you pretty much want to commit to Maven. Even if you do configure Eclipse with Eclipse-specific dependencies, anytime you update your project configuration using Maven, it will do a complete rewrite of your configuration.
I strongly recommend converting any of your other project build dependencies into Maven-enabled projects that can be used as Maven dependencies.
In your specific case (through using the Maven modules), this means ensuring that each of your modules are imported into Eclipse as m2e-enabled projects. m2e will then automatically wire in the dependencies between modules and other dependent projects.
Im scratching my head as to why you would need your modules defined as dependencies on your top level project. Are you trying to avoid having to define the (cross) dependencies at a module level? In any case, as per other suggestions, first of all put your dependencies in the correct places in your POM, then either run
mvn eclipse:clean eclipse:eclipse
to update your Eclipse settings, or better still, make sure m2eclipse is installed and import your maven projects directly into the IDE.

Categories