“duplicate class” on boilerplate generation (GWTP) with maven

Question

After using the boilerplate mechanisms of GWTP I get the error that the classes (which where generated) are already existing.

The folder target/generated-sources con

Answer 1

The problem was that the maven-processor-plugin and the maven-compiler-plugin where generating the (same) sources to different folders. The solution is to disable one processor. I decided that the maven-processor-plugin will be disabled.

The other option is to add <compilerArgument>-proc:none</compilerArgument> to the maven-compiler-plugin. This has the benifit that mvn generate-sources is working.