The default source folder for a Java Maven project is src/main/java. In the project on the right, the source folder is set to src via the following line in the pom.xml file:

<sourceDirectory>src</sourceDirectory>

If you remove the line or change the value, right-click the project and choose Maven > Update Project... to have Eclipse read the pom.xml file and update the source folder location accordingly.

I think the location depends on how the source is generated and handled.

1. The source code is generated automatically during the build process: Then i would use target/main/java/, target/test/java/ and so on. This code is not checked in into CVS since you can rebuild it fairly easy. In case you clean your project the target directory will be removed and the source will be rebuild.

2. The source code is generated manually by an external tool or similar: I would use generated/src/main/java/, generated/src/test/java/, generated/src/main/resources/ and so on. This code should be checked in. A benefit is, as soon you see that the top-level directory name is generated you know that all files/directories below are also generated. Also you have the standard maven directory structure under the top-level directory. Another point is that clean-up is easy, just delete generated and recreate it, without looking through many other directories (like in your example: src/main/generated-java and src/test/generated-java).

EDIT: Another nice solution would be to create a maven project which only contains the generated source like myproject-generated-1.0.3.jar. This project would be a dependency in your real application. Then you would just put your generated source int src/main/java.

Maven and other build management environments (e.g. gradle) are based on the assumption that you do automated testing via e.g. unit tests. For that you need extra code for testing that should not be included in your final product delivered to your customer.

Thus, everything that goes into src/main/java is per default packaged into the product that you would deliver for your customer whereas everything that you put into src/test/java is not.

This is an advantage for various reasons:

• your delivered products are smaller
• it is easier to to find testrelated code inside your project
• you can load various libraries only for testing.
• ...

Assuming you have a good reason to do this, you can rename the folders and indicate to maven what is the edited one by specifying the appropriate properties/sections in pom.xml of your project. I suppose m2e will pick up the changes once made to the pom.

The relevant section in your case would be (from the superpom)

    <sourceDirectory>${project.basedir}/src/main/java</sourceDirectory>
    <testSourceDirectory>${project.basedir}/src/test/java</testSourceDirectory>
    <resources>
      <resource>
        <directory>${project.basedir}/src/main/resources</directory>
      </resource>
    </resources>
    <testResources>
      <testResource>
        <directory>${project.basedir}/src/test/resources</directory>
      </testResource>
    </testResources>

If you want to add additional source folders or resources (not subfolders), then you can use build helper maven plugin. Again, not sure what m2e will do.

To add a resource folder in eclipse: