Why can't the compiler find the "MappingProcessor" annotation processor?

Question

I'm using IntelliJ 13.0.2 on OSX 10.9.5, using java 1.8. I get this error when trying to run a unit test inside IntelliJ. When I run compile or test via maven at the command line, it runs fine.

I've gone into File->Other Settings->Default Settings->Compiler->Annotation Processors and unchecked Enable annotation processing. I've also tried it with Enable annotation processing checked, and left the defaults selected.

We're running our tests with

@RunWith(MockitoJUnitRunner.class)

and the Annotation processor it can't find is org.mapstruct.ap.MappingProcessor. I don't know where it's getting that from, it's not in our imports. Maybe a dependency from Mockito?

Answer 1

This is happening because of realm. You can use these dependencies

classpath "io.realm:realm-gradle-plugin:2.0.0-SNAPSHOT

classpath 'com.android.tools.build:gradle:2.0.0-alpha3

classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8

2.0.0 version of snapshots. Good Luck!

Answer 2

In the more general case that I encountered with my own Annotation Processor, here's what was necessary.

In the settings page, choose the "Processor Path" radio button. This has to be the target jar, you should try to locate that MappingProcessor jar.

I believe that this is because when running on the terminal, you would do:
javac -cp <pathToAnnotationProcessor.jar> <path to source.java>