Java annotation processor not generating file in generated sources

Question

I am writing a simple java annotation processor which generates a the java class using JavaPoet and then write it into the filer.


@AutoService(Processor.class)
public class ConfigProcessor extends AbstractProcessor {

    private Types    typeUtils;
    private Elements elementUtils;
    private Filer    filer;
    private Messager messager;

    @Override
    public synchronized void init(ProcessingEnvironment processingEnv) {
        super.init(processingEnv);
        typeUtils    = processingEnv.getTypeUtils();
        elementUtils = processingEnv.getElementUtils();
        filer        = processingEnv.getFiler();
        messager     = processingEnv.getMessager();
    }

    @Override
    public Set<String> getSupportedAnnotationTypes() {
        Set<String> annotataions = new LinkedHashSet<String>();
        annotataions.add(Config.class.getCanonicalName());
        return annotataions;
    }

    @Override
    public SourceVersion getSupportedSourceVersion() {
        return SourceVersion.latestSupported();
    }

    @Override
    public boolean process(Set<? extends TypeElement> annotations,
                           RoundEnvironment roundEnv) {

        for (Element annotatedElement : roundEnv.getElementsAnnotatedWith(RemoteConfig.class)) {

            TypeSpec configImpl = // generating 

            JavaFile javaFile = JavaFile.builder(elementUtils.getPackageOf(annotatedElement).getQualifiedName().toString(),
                                                 configImpl)
                                        .build();

            try {
                javaFile.writeTo(filer);
            } catch (IOException e) {
                messager.printMessage(Diagnostic.Kind.ERROR,
                                      "Failed to generate implementation",
                                      annotatedElement);
                return true;
            }
        }
        return true;
    }
}

This annotation processor is saving the files into target/classes/mypackage instead of target/generated-sources/annotations/mypackage

I have tried setting the generatedSourcesDirectory directory in the maven compiler plugin to the generated sources directory but it still generates it in the classes folder.

How do I make the generated classes be saved in the generated-sources folder?

Have you found solution to this problem? – h3wro Mar 16 '20 at 18:09 — h3wro, Mar 16 '20 at 18:09

score 1 · Accepted Answer · answered May 15 '20 at 14:54

I had exactly the same problem and the solution looks quite strange. If I configure maven-compiler-plugin only by setting properties it always generates source code directly in target/classes, but when I explicitly define maven-compiler-plugin in plugins section then my code is generated in target/generated-sources/annotations

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>${java.version}</source>
                <target>${java.version}</target>
            </configuration>
        </plugin>
    </plugins>
</build>

Here's a sample where it works fine and when you remove the plugin the same problem occurs: https://github.com/sockeqwe/annotationprocessing101

Java annotation processor not generating file in generated sources

1 Answers1