M2E and having maven generated source folders as eclipse source folders

Question

I have a maven project in eclipse and have maven goals that run annotation processors to generate code. The output folder for this code is target/generated-sources/apt.

In order for Eclipse to see this generated code I need to add target/generated-sources/apt as a source folder to the Eclipse project.

However, this causes there to be an error of type "Maven Configuration Problem" saying

Project configuration is not up-to-date with pom.xml. Run project configuration update

I think I understand why this is the case as Eclipse has a different set of source folders to Maven's set. But I need this different set, as I need Eclipse to be able to see the generated source folders...

When doing a pure Maven built, these source folders will be included in the build, by Maven.

BTW, I have upgraded to the official Eclipse release of the Maven Eclipse plugin, m2e 1.0 - what used to be m2eclipse. I'd like to see if I can find a work around/solution to this with the m2e plugin before I have to go back to the old m2eclipse version.

Solution 1

You need to attach the source directory with the build-helper-plugin.

Like so:

 <plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>build-helper-maven-plugin</artifactId>
    <executions>
        <execution>
            <id>add-source</id>
            <phase>generate-sources</phase>
            <goals>
                <goal>add-source</goal>
            </goals>
            <configuration>
                <sources>
                    <source>${project.build.directory}/generated-sources/java/</source>
                </sources>
            </configuration>
        </execution>
    </executions>
 </plugin>

You will also need to:

• Install the "Apt M2E Connector" from the Eclipse Marketplace. To do so click the error in the Overview tab of your pom.xml and select "Discover".
• Ensure there are no plugin execution filters for the build-helper-maven-plugin (see https://www.eclipse.org/m2e/documentation/m2e-execution-not-covered.html)

Solution 2

Right-click the Error message:

Project configuration is not up-to-date with pom.xml Run project configuration update

in the Problems View and select Quick Fix and click Finish to select the default Update project configuration. This fixes it.

Solution 3

After switching to new versions of m2e/maven/apt,... i had builderrors because of the duplicated files, caused by the added buildpath by the buildhelper, so i needed to remove the "apt-generated"-Folders from the buildhelper.

To fix the Problem in Eclipse, not adding the "apt-generated"-folder via Update Maven Configuration in M2E, i've written a M2E Plugin to fix this problem. It adds the outputDirectories configured in the maven-apt-plugin to the buildpath of the Project.

https://apt-m2e.googlecode.com

Solution 4

In m2e 1.0 the handling of Maven plugins has changed. You might be lacking a specific m2e extension for your code generating plugin. Here is all the documentation I managed to find.

This bug report may also be relevant.

Solution 5

https://bugs.eclipse.org/bugs/show_bug.cgi?id=350081

request on CXF JIRA (see 1) to add lifecycle mappings in the cxf-codegen-plugin itself. This would require m2e 1.1 but I believe it is better approach than having connectors built outside of cxf project, assuming that lifecycle mapping API would change less frequently than cxf-codegen-plugin and cxf.

View more solutions