GH-1052 - ApplicationModuleSource now uses JavaPackage.findAnnotation(…).

This is to make sure that marker types annotated with @PackageInfo are considered, too. Deprecate JavaPackage.getAnnotation(…) as it's not used anywhere anymore and we would like to consistently consider package info marker types when looking up package annotations.

Author: odrotbohm

spring-modulith-core/src/main/java/org/springframework/modulith/core/ApplicationModuleSource.java

@@ -220,7 +220,7 @@ static <T extends Annotation> ApplicationModuleSourceMetadata forAnnotation(Clas
 				@Override
 				public Optional<ApplicationModuleIdentifier> lookupIdentifier(JavaPackage pkg) {
 
-					return pkg.getAnnotation(annotation)
+					return pkg.findAnnotation(annotation)
 							.map(extractor)
 							.filter(StringUtils::hasText)
 							.map(ApplicationModuleIdentifier::of);

spring-modulith-core/src/main/java/org/springframework/modulith/core/JavaPackage.java

@@ -271,8 +271,9 @@ public Stream<JavaClass> stream() {
 	 */
 	public <A extends Annotation> Optional<A> getAnnotation(Class<A> annotationType) {
 
-		return packageClasses.that(have(simpleName(PACKAGE_INFO_NAME)) //
-				.and(are(metaAnnotatedWith(annotationType)))) //
+		var isPackageInfo = have(simpleName(PACKAGE_INFO_NAME)).or(are(metaAnnotatedWith(PackageInfo.class)));
+
+		return packageClasses.that(isPackageInfo.and(are(metaAnnotatedWith(annotationType)))) //
 				.toOptional() //
 				.map(it -> it.reflect())
 				.map(it -> AnnotatedElementUtils.getMergedAnnotation(it, annotationType));
@@ -384,23 +385,22 @@ Optional<JavaPackage> getSubPackage(String localName) {
 	 */
 	public <A extends Annotation> Optional<A> findAnnotation(Class<A> annotationType) {
 
-		return getAnnotation(annotationType)
-				.or(() -> {
+		var isPackageInfo = have(simpleName(PACKAGE_INFO_NAME)).or(are(metaAnnotatedWith(PackageInfo.class)));
 
-					var annotatedTypes = toSingle().packageClasses
-							.that(are(metaAnnotatedWith(PackageInfo.class).and(are(metaAnnotatedWith(annotationType)))))
-							.stream()
-							.map(it -> it.getAnnotationOfType(annotationType))
-							.toList();
+		var annotatedTypes = toSingle().packageClasses
+				.that(isPackageInfo.and(are(metaAnnotatedWith(annotationType))))
+				.stream()
+				.map(JavaClass::reflect)
+				.map(it -> AnnotatedElementUtils.findMergedAnnotation(it, annotationType))
+				.toList();
 
-					if (annotatedTypes.size() > 1) {
+		if (annotatedTypes.size() > 1) {
 
-						throw new IllegalStateException(MULTIPLE_TYPES_ANNOTATED_WITH.formatted(name,
-								FormattableType.of(annotationType).getAbbreviatedFullName(), annotatedTypes));
-					}
+			throw new IllegalStateException(MULTIPLE_TYPES_ANNOTATED_WITH.formatted(name,
+					FormattableType.of(annotationType).getAbbreviatedFullName(), annotatedTypes));
+		}
 
-					return annotatedTypes.isEmpty() ? Optional.empty() : Optional.of(annotatedTypes.get(0));
-				});
+		return annotatedTypes.isEmpty() ? Optional.empty() : Optional.of(annotatedTypes.get(0));
 	}
 
 	/**

spring-modulith-core/src/test/java/org/springframework/modulith/core/ApplicationModuleSourceUnitTests.java

@@ -56,4 +56,17 @@ void doesNotPickUpIdFromNestedPackages() {
 				.contains("module", // picked from package name not from annotation in nested package
 						"gh-1042-nested"); // from annotation in nested package
 	}
+
+	@Test // GH-1052
+	void detectsApplicationModuleMetadataOnAnnotatedType() {
+
+		var pkg = TestUtils.getPackage("reproducers");
+
+		var sources = ApplicationModuleSource.from(pkg, root -> root.getSubPackage("gh1052").stream(), false);
+
+		assertThat(sources).hasSize(1)
+				.extracting(ApplicationModuleSource::getIdentifier)
+				.extracting(ApplicationModuleIdentifier::toString)
+				.containsExactly("on-marker-type");
+	}
 }

spring-modulith-core/src/test/java/reproducers/gh1052/Marker.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package reproducers.gh1052;
+
+import org.springframework.modulith.ApplicationModule;
+
+/**
+ * @author Oliver Drotbohm
+ */
+@ApplicationModule(id = "on-marker-type")
+class Marker {}

spring-modulith-integration-test/src/test/java/org/springframework/modulith/core/JavaPackageUnitTests.java

@@ -53,7 +53,7 @@ void detectsDirectSubPackages() throws Exception {
 	void findsAnnotationOnPackageInfo() {
 
 		var annotation = JavaPackage.of(Classes.of(PKG_CLASSES), "pkg.onpackage") //
-				.getAnnotation(ApplicationModule.class);
+				.findAnnotation(ApplicationModule.class);
 
 		assertThat(annotation).hasValueSatisfying(it -> {
 			assertThat(it.displayName()).isEqualTo("onPackage");