Java – How to resolve unknown classes and fail to parse symbols in Android Studio java library modules

Using Android Studio and creating a java library module as part of a subproject, I get an error in the following java statement:

javaFile.writeTo(System.out);

It says that the symbol “writeTo” and the unknown class “System.out” cannot be resolved.

This is the gist of the source code class

import com.squareup.javapoet.JavaFile;
import com.squareup.javapoet.MethodSpec;
import com.squareup.javapoet.TypeSpec;

import javax.lang.model.element.Modifier;

public class MyClass {

...

JavaFile javaFile = JavaFile.builder("com.foobar.helloworld", helloWorld)
        .build();

javaFile.writeTo(System.out);
}

It’s hard to say if you don’t know exactly what your exception is, but when I test the submodule annotation processor, I pop something similar. When linking the processor to my main module, I get a java.lang.NoClassDefFoundError: com/squareup/javapoet/MethodSpec. I’m using android-apt to get the annotation processor to work, so in my build.config my dependencies have apt config definitions:

dependencies {
    ...

apt 'com.squareup:javapoet:1.7.0' // <- Note that since my Processor used javapoet, I had to include Javapoet in the main module's apt dependency as well as my processor jar
    apt files('.. /processor/build/libs/processor.jar')
}

Once I included the dependencies mentioned above, then everything works fine. Not sure if this applies to your case without more details, but that got me back on track.