Eclipse - Annotation Processor Exception

Annotation Processor Code

import com.google.auto.service.AutoService;
import com.squareup.javapoet.JavaFile;
import com.squareup.javapoet.TypeName;
import com.squareup.javapoet.TypeSpec;

import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.Processor;
import javax.annotation.processing.RoundEnvironment;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.Element;
import javax.lang.model.element.Modifier;
import javax.lang.model.element.TypeElement;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

@AutoService(Processor.class)
public class TestAnnotationProcessor extends AbstractProcessor {
	private static String ANNOTATION = TestAnnotation.class.getName();

	@Override
	public Set<String> getSupportedAnnotationTypes() {
		return new HashSet<>(Arrays.asList(ANNOTATION));
	}

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

	@Override
	public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
		boolean match = annotations.stream().anyMatch(e -> e.toString().equals(ANNOTATION));
		if (!match) {
			return false;
		}

		Set<? extends Element> elementsAnnotatedWith = roundEnv.getElementsAnnotatedWith(TestAnnotation.class);
		for (Element element : elementsAnnotatedWith) {
			TypeSpec typeSpec = TypeSpec.classBuilder(element.getSimpleName().toString() + "_Impl")
					.addSuperinterface(TypeName.get(element.asType()))
					.addModifiers(Modifier.PUBLIC)
					.build();

			String packageName = element.getEnclosingElement().toString();
			JavaFile javaFile = JavaFile.builder(packageName, typeSpec).build();
			try {
				javaFile.writeTo(processingEnv.getFiler());
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}

		return false;
	}
}

Annotation

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.CLASS)
public @interface TestAnnotation {

}


Test Code :

@TestAnnotation
public interface Mapper {

}


Eclipse Exception Trace

Description	Resource	Path	Location	Type
java.lang.NullPointerException
	at org.eclipse.jdt.apt.core.internal.generatedfile.GeneratedFileManager.saveCompilationUnit(GeneratedFileManager.java:1494)
	at org.eclipse.jdt.apt.core.internal.generatedfile.GeneratedFileManager.generateFileDuringBuild(GeneratedFileManager.java:542)
	at org.eclipse.jdt.internal.apt.pluggable.core.filer.IdeJavaSourceOutputStream.close(IdeJavaSourceOutputStream.java:68)
	at sun.nio.cs.StreamEncoder.implClose(Unknown Source)
	at sun.nio.cs.StreamEncoder.close(Unknown Source)
	at java.io.OutputStreamWriter.close(Unknown Source)
	at java.io.BufferedWriter.close(Unknown Source)
	at java.io.PrintWriter.close(Unknown Source)
	at com.squareup.javapoet.JavaFile.$closeResource(JavaFile.java:99)
	at com.squareup.javapoet.JavaFile.writeTo(JavaFile.java:117)
	at com.test.processor.TestAnnotationProcessor.process(TestAnnotationProcessor.java:57)
	at org.eclipse.jdt.internal.compiler.apt.dispatch.RoundDispatcher.handleProcessor(RoundDispatcher.java:139)
	at org.eclipse.jdt.internal.compiler.apt.dispatch.RoundDispatcher.round(RoundDispatcher.java:121)
	at org.eclipse.jdt.internal.compiler.apt.dispatch.BaseAnnotationProcessorManager.processAnnotations(BaseAnnotationProcessorManager.java:159)
	at org.eclipse.jdt.internal.apt.pluggable.core.dispatch.IdeAnnotationProcessorManager.processAnnotations(IdeAnnotationProcessorManager.java:135)
	at org.eclipse.jdt.internal.compiler.Compiler.processAnnotations(Compiler.java:933)
	at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:443)
	at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:419)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:372)
	at org.eclipse.jdt.internal.core.builder.IncrementalImageBuilder.compile(IncrementalImageBuilder.java:331)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:305)
	at org.eclipse.jdt.internal.core.builder.IncrementalImageBuilder.build(IncrementalImageBuilder.java:136)
	at org.eclipse.jdt.internal.core.builder.JavaBuilder.buildDeltas(JavaBuilder.java:267)
	at org.eclipse.jdt.internal.core.builder.JavaBuilder.build(JavaBuilder.java:195)
	at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:735)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:206)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:246)
	at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:301)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:304)
	at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:360)
	at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:383)
	at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:142)
	at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:232)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)
	Mapper.java	/TestPOJO/src/com/test	line 12	Annotation Problem (Java 6 processor)