Merge pull request #13904 from ayudovin:make-springbootconfigurationfinder-public-and-usable-with-annotation

* pr/13904:
  Polish contribution
  Make SpringBootConfigurationFinder public and usable with other annotations

Author: snicoll

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootConfigurationFinder.java renamed to spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/AnnotatedClassFinder.java

@@ -16,42 +16,63 @@
 
 package org.springframework.boot.test.context;
 
+import java.lang.annotation.Annotation;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
 
 import org.springframework.beans.factory.config.BeanDefinition;
-import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
 import org.springframework.core.type.filter.AnnotationTypeFilter;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
 /**
- * Internal utility class to scan for a {@link SpringBootConfiguration} class.
+ * Utility class to find a class annotated with a particular annotation in a hierarchy.
  *
  * @author Phillip Webb
+ * @author Artsiom Yudovin
+ * @author Stephane Nicoll
+ * @since 2.1.0
  */
-final class SpringBootConfigurationFinder {
+public final class AnnotatedClassFinder {
 
 	private static final Map<String, Class<?>> cache = Collections
 			.synchronizedMap(new Cache(40));
 
 	private final ClassPathScanningCandidateComponentProvider scanner;
 
-	SpringBootConfigurationFinder() {
+	/**
+	 * Create a new instance with the {@code annotationType} to find.
+	 * @param annotationType the annotation to find
+	 */
+	public AnnotatedClassFinder(Class<? extends Annotation> annotationType) {
+		Assert.notNull(annotationType, "AnnotationType must not be null");
 		this.scanner = new ClassPathScanningCandidateComponentProvider(false);
-		this.scanner.addIncludeFilter(
-				new AnnotationTypeFilter(SpringBootConfiguration.class));
+		this.scanner.addIncludeFilter(new AnnotationTypeFilter(annotationType));
 		this.scanner.setResourcePattern("*.class");
 	}
 
+	/**
+	 * Find the first {@link Class} that is annotated with the target annotation, starting
+	 * from the package defined by the given {@code source} up to the root.
+	 * @param source the source class to use to initiate the search
+	 * @return the first {@link Class} annotated with the target annotation within the
+	 * hierarchy defined by the given {@code source} or {@code null} if none is found.
+	 */
 	public Class<?> findFromClass(Class<?> source) {
 		Assert.notNull(source, "Source must not be null");
 		return findFromPackage(ClassUtils.getPackageName(source));
 	}
 
+	/**
+	 * Find the first {@link Class} that is annotated with the target annotation, starting
+	 * from the package defined by the given {@code source} up to the root.
+	 * @param source the source package to use to initiate the search
+	 * @return the first {@link Class} annotated with the target annotation within the
+	 * hierarchy defined by the given {@code source} or {@code null} if none is found.
+	 */
 	public Class<?> findFromPackage(String source) {
 		Assert.notNull(source, "Source must not be null");
 		Class<?> configuration = cache.get(source);

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTestContextBootstrapper.java

@@ -238,7 +238,7 @@ protected Class<?>[] getOrFindConfigurationClasses(
 		if (containsNonTestComponent(classes) || mergedConfig.hasLocations()) {
 			return classes;
 		}
-		Class<?> found = new SpringBootConfigurationFinder()
+		Class<?> found = new AnnotatedClassFinder(SpringBootConfiguration.class)
 				.findFromClass(mergedConfig.getTestClass());
 		Assert.state(found != null,
 				"Unable to find a @SpringBootConfiguration, you need to use "

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/SpringBootConfigurationFinderTests.java renamed to spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/AnnotatedClassFinderTests.java

@@ -20,22 +20,24 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.test.context.example.ExampleConfig;
 import org.springframework.boot.test.context.example.scan.Example;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Tests for {@link SpringBootConfigurationFinder}.
+ * Tests for {@link AnnotatedClassFinder}.
  *
  * @author Phillip Webb
  */
-public class SpringBootConfigurationFinderTests {
+public class AnnotatedClassFinderTests {
 
 	@Rule
 	public ExpectedException thrown = ExpectedException.none();
 
-	private SpringBootConfigurationFinder finder = new SpringBootConfigurationFinder();
+	private AnnotatedClassFinder finder = new AnnotatedClassFinder(
+			SpringBootConfiguration.class);
 
 	@Test
 	public void findFromClassWhenSourceIsNullShouldThrowException() {

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/example/ExampleConfig.java

@@ -17,10 +17,10 @@
 package org.springframework.boot.test.context.example;
 
 import org.springframework.boot.SpringBootConfiguration;
-import org.springframework.boot.test.context.SpringBootConfigurationFinderTests;
+import org.springframework.boot.test.context.AnnotatedClassFinderTests;
 
 /**
- * Example config used in {@link SpringBootConfigurationFinderTests}.
+ * Example config used in {@link AnnotatedClassFinderTests}.
  *
  * @author Phillip Webb
  */

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/example/scan/Example.java

@@ -16,10 +16,10 @@
 
 package org.springframework.boot.test.context.example.scan;
 
-import org.springframework.boot.test.context.SpringBootConfigurationFinderTests;
+import org.springframework.boot.test.context.AnnotatedClassFinderTests;
 
 /**
- * Example class used in {@link SpringBootConfigurationFinderTests}.
+ * Example class used in {@link AnnotatedClassFinderTests}.
  *
  * @author Phillip Webb
  */

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/example/scan/sub/SubExampleConfig.java

@@ -17,11 +17,11 @@
 package org.springframework.boot.test.context.example.scan.sub;
 
 import org.springframework.boot.SpringBootConfiguration;
-import org.springframework.boot.test.context.SpringBootConfigurationFinderTests;
+import org.springframework.boot.test.context.AnnotatedClassFinderTests;
 
 /**
- * Example config used in {@link SpringBootConfigurationFinderTests}. Should not be found
- * since scanner should only search upwards.
+ * Example config used in {@link AnnotatedClassFinderTests}. Should not be found since
+ * scanner should only search upwards.
  *
  * @author Phillip Webb
  */