How to teach Eclipse to include Maven source packages on the source path?

Question

How can I teach Eclipse with m2eclipse to include all source .jar in my local Maven repository in the source path when looking up library source files while debugging?

Answer 1

Go to Window->Preferences->Maven->Installations and ensure that Maven is configured to use your Maven installation rather than the embedder.

If it is not configured to do so, Select Add... and browse to the root of your Eclipse install, and OK the selection.

M2eclipse will then read your settings file, discover your local repository, and automatically attach the sources available in the local repository.

If m2eclipse is pointing at your local repository, you should be able to right-click and select Maven->Download Sources, or enable the preferences to download them automatically. If the sources are already present, they should simply be attached. See this answer for details and pretty screenshots.

If after following those steps sources are still not being attached, it suggests that there is something wrong with your Maven installation. You could attempt to update the m2eclipse plugin to the latest to see if it resolves the problem.

Answer 2

I was having this exact same problem-- I used the Maven Source Plugin to deploy the source to our repo, and when I included that project in a separate one, try as I might, it wouldn't include the source on the Eclipse build path. I had done this before for a previous job and I knew it was possible to have the source included on the buildpath so that Eclipse will automatically link the source in the integrated debugger simply by clicking "Download Sources" as described in the other answers.

Here is what I had (which was not working for me). I had gotten this snippet of code from the maven-source-plugin's webpage:

        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-source-plugin</artifactId>
        <executions>
            <execution>
                <id>attach-sources</id>
                <goals>
                    <goal>jar</goal>
                </goals>
            </execution>
        </executions>

This would package the source in a separate JAR and upload it to our repo, but it wouldn't automatically attach to the Eclipse debugger. Eventually, I found that I needed a <configuration><attach>true</attach></configuration> snippet included, like so:

        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-source-plugin</artifactId>
        <executions>
            <execution>
                <id>attach-sources</id>
                <goals>
                    <goal>jar</goal>
                </goals>
            </execution>
        </executions>
        <configuration>
            <attach>true</attach>
        </configuration>

After this, the source automatically attaches to the Eclipse debugger by right-clicking on the project in Package Explorer and doing "Maven > Download Sources".

I hope this solves your problem.

Answer 3

Keep in mind that depending on your m2eclipse version you might be affected by this problem. The problem breaks source code lookup when debugging.

Answer 4

I am also encountering the m2eclipse bug described by Anatoli. It's still unresolved and it seems to me that it's the cause for the questioner's problem as well.