Add exclude support to @ImportAutoConfiguration

Update `@ImportAutoConfiguration` with support for an exclude attribute
that works in a similar way to `@EnableAutoConfiguration`.

Also update existing `@Test...` annotation with exclude attribute
aliases.

Fixes gh-6809

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/ImportAutoConfiguration.java

@@ -24,6 +24,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 import org.springframework.context.annotation.Import;
+import org.springframework.core.annotation.AliasFor;
 
 /**
  * Import and apply the specified auto-configuration classes. Applies the same ordering
@@ -46,12 +47,27 @@ import org.springframework.context.annotation.Import;
 @Import(ImportAutoConfigurationImportSelector.class)
 public @interface ImportAutoConfiguration {
 
+	/**
+	 * The auto-configuration classes that should be imported. This is an alias for
+	 * {@link #classes()}.
+	 * @return the classes to import
+	 */
+	@AliasFor("classes")
+	Class<?>[] value() default {};
+
 	/**
 	 * The auto-configuration classes that should be imported. When empty, the classes are
 	 * specified using an entry in {@code META-INF/spring.factories} where the key is the
 	 * fully-qualified name of the annotated class.
 	 * @return the classes to import
 	 */
-	Class<?>[] value() default {};
+	@AliasFor("value")
+	Class<?>[] classes() default {};
+
+	/**
+	 * Exclude specific auto-configuration classes such that they will never be applied.
+	 * @return the classes to exclude
+	 */
+	Class<?>[] exclude() default {};
 
 }

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/ImportAutoConfigurationImportSelector.java

@@ -24,13 +24,18 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
+import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.core.io.support.SpringFactoriesLoader;
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.ObjectUtils;
 
 /**
  * Variant of {@link EnableAutoConfigurationImportSelector} for
@@ -59,47 +64,27 @@ class ImportAutoConfigurationImportSelector
 	@Override
 	protected List<String> getCandidateConfigurations(AnnotationMetadata metadata,
 			AnnotationAttributes attributes) {
-		try {
-			return getCandidateConfigurations(
-					ClassUtils.forName(metadata.getClassName(), null));
-		}
-		catch (Exception ex) {
-			throw new IllegalStateException(ex);
+		List<String> candidates = new ArrayList<String>();
+		Map<Class<?>, List<Annotation>> annotations = getAnnotations(metadata);
+		for (Map.Entry<Class<?>, List<Annotation>> entry : annotations.entrySet()) {
+			collectCandidateConfigurations(entry.getKey(), entry.getValue(), candidates);
 		}
+		return candidates;
 	}
 
-	private List<String> getCandidateConfigurations(Class<?> source) {
-		Set<String> candidates = new LinkedHashSet<String>();
-		collectCandidateConfigurations(source, candidates, new HashSet<Class<?>>());
-		return new ArrayList<String>(candidates);
-	}
-
-	private void collectCandidateConfigurations(Class<?> source, Set<String> candidates,
-			Set<Class<?>> seen) {
-		if (source != null && seen.add(source)) {
-			for (Annotation annotation : source.getDeclaredAnnotations()) {
-				if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotation)) {
-					collectCandidateConfigurations(source, annotation, candidates, seen);
-				}
-			}
-			collectCandidateConfigurations(source.getSuperclass(), candidates, seen);
-		}
-	}
-
-	private void collectCandidateConfigurations(Class<?> source, Annotation annotation,
-			Set<String> candidates, Set<Class<?>> seen) {
-		if (ANNOTATION_NAMES.contains(annotation.annotationType().getName())) {
+	private void collectCandidateConfigurations(Class<?> source,
+			List<Annotation> annotations, List<String> candidates) {
+		for (Annotation annotation : annotations) {
 			candidates.addAll(getConfigurationsForAnnotation(source, annotation));
 		}
-		collectCandidateConfigurations(annotation.annotationType(), candidates, seen);
 	}
 
 	private Collection<String> getConfigurationsForAnnotation(Class<?> source,
 			Annotation annotation) {
-		String[] value = (String[]) AnnotationUtils
-				.getAnnotationAttributes(annotation, true).get("value");
-		if (value.length > 0) {
-			return Arrays.asList(value);
+		String[] classes = (String[]) AnnotationUtils
+				.getAnnotationAttributes(annotation, true).get("classes");
+		if (classes.length > 0) {
+			return Arrays.asList(classes);
 		}
 		return SpringFactoriesLoader.loadFactoryNames(source,
 				getClass().getClassLoader());
@@ -108,7 +93,52 @@ class ImportAutoConfigurationImportSelector
 	@Override
 	protected Set<String> getExclusions(AnnotationMetadata metadata,
 			AnnotationAttributes attributes) {
-		return Collections.emptySet();
+		Set<String> exclusions = new LinkedHashSet<String>();
+		Class<?> source = ClassUtils.resolveClassName(metadata.getClassName(), null);
+		for (String annotationName : ANNOTATION_NAMES) {
+			AnnotationAttributes merged = AnnotatedElementUtils
+					.getMergedAnnotationAttributes(source, annotationName);
+			Class<?>[] exclude = (merged == null ? null
+					: merged.getClassArray("exclude"));
+			if (exclude != null) {
+				for (Class<?> excludeClass : exclude) {
+					exclusions.add(excludeClass.getName());
+				}
+			}
+		}
+		for (List<Annotation> annotations : getAnnotations(metadata).values()) {
+			for (Annotation annotation : annotations) {
+				String[] exclude = (String[]) AnnotationUtils
+						.getAnnotationAttributes(annotation, true).get("exclude");
+				if (!ObjectUtils.isEmpty(exclude)) {
+					exclusions.addAll(Arrays.asList(exclude));
+				}
+			}
+		}
+		return exclusions;
+	}
+
+	private Map<Class<?>, List<Annotation>> getAnnotations(AnnotationMetadata metadata) {
+		MultiValueMap<Class<?>, Annotation> annotations = new LinkedMultiValueMap<Class<?>, Annotation>();
+		Class<?> source = ClassUtils.resolveClassName(metadata.getClassName(), null);
+		collectAnnotations(source, annotations, new HashSet<Class<?>>());
+		return Collections.unmodifiableMap(annotations);
+	}
+
+	private void collectAnnotations(Class<?> source,
+			MultiValueMap<Class<?>, Annotation> annotations, HashSet<Class<?>> seen) {
+		if (source != null && seen.add(source)) {
+			for (Annotation annotation : source.getDeclaredAnnotations()) {
+				if (!AnnotationUtils.isInJavaLangAnnotationPackage(annotation)) {
+					if (ANNOTATION_NAMES
+							.contains(annotation.annotationType().getName())) {
+						annotations.add(source, annotation);
+					}
+					collectAnnotations(annotation.annotationType(), annotations, seen);
+				}
+			}
+			collectAnnotations(source.getSuperclass(), annotations, seen);
+		}
 	}
 
 	@Override

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/ImportAutoConfigurationImportSelectorTests.java

@@ -29,6 +29,7 @@ import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration;
 import org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration;
+import org.springframework.core.annotation.AliasFor;
 import org.springframework.core.env.Environment;
 import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.type.AnnotationMetadata;
@@ -69,6 +70,15 @@ public class ImportAutoConfigurationImportSelectorTests {
 		assertThat(imports).containsExactly(FreeMarkerAutoConfiguration.class.getName());
 	}
 
+	@Test
+	public void importsAreSelectedUsingClassesAttribute() throws Exception {
+		AnnotationMetadata annotationMetadata = new SimpleMetadataReaderFactory()
+				.getMetadataReader(ImportFreeMarkerUsingClassesAttribute.class.getName())
+				.getAnnotationMetadata();
+		String[] imports = this.importSelector.selectImports(annotationMetadata);
+		assertThat(imports).containsExactly(FreeMarkerAutoConfiguration.class.getName());
+	}
+
 	@Test
 	public void propertyExclusionsAreNotApplied() throws Exception {
 		AnnotationMetadata annotationMetadata = new SimpleMetadataReaderFactory()
@@ -97,22 +107,58 @@ public class ImportAutoConfigurationImportSelectorTests {
 		assertThat(imports).containsOnly(ThymeleafAutoConfiguration.class.getName());
 	}
 
+	@Test
+	public void exclusionsAreApplied() throws Exception {
+		AnnotationMetadata annotationMetadata = new SimpleMetadataReaderFactory()
+				.getMetadataReader(MultipleImportsWithExclusion.class.getName())
+				.getAnnotationMetadata();
+		String[] imports = this.importSelector.selectImports(annotationMetadata);
+		assertThat(imports).containsOnly(FreeMarkerAutoConfiguration.class.getName());
+	}
+
+	@Test
+	public void exclusionsAliasesAreApplied() throws Exception {
+		AnnotationMetadata annotationMetadata = new SimpleMetadataReaderFactory()
+				.getMetadataReader(
+						ImportWithSelfAnnotatingAnnotationExclude.class.getName())
+				.getAnnotationMetadata();
+		String[] imports = this.importSelector.selectImports(annotationMetadata);
+		assertThat(imports).isEmpty();
+	}
+
 	@ImportAutoConfiguration(FreeMarkerAutoConfiguration.class)
 	static class ImportFreeMarker {
 
 	}
 
+	@ImportAutoConfiguration(classes = FreeMarkerAutoConfiguration.class)
+	static class ImportFreeMarkerUsingClassesAttribute {
+
+	}
+
 	@ImportOne
 	@ImportTwo
 	static class MultipleImports {
 
 	}
 
+	@ImportOne
+	@ImportTwo
+	@ImportAutoConfiguration(exclude = ThymeleafAutoConfiguration.class)
+	static class MultipleImportsWithExclusion {
+
+	}
+
 	@SelfAnnotating
 	static class ImportWithSelfAnnotatingAnnotation {
 
 	}
 
+	@SelfAnnotating(excludeAutoConfiguration = ThymeleafAutoConfiguration.class)
+	static class ImportWithSelfAnnotatingAnnotationExclude {
+
+	}
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@ImportAutoConfiguration(FreeMarkerAutoConfiguration.class)
 	static @interface ImportOne {
@@ -130,6 +176,9 @@ public class ImportAutoConfigurationImportSelectorTests {
 	@SelfAnnotating
 	static @interface SelfAnnotating {
 
+		@AliasFor(annotation = ImportAutoConfiguration.class, attribute = "exclude")
+		Class<?>[] excludeAutoConfiguration() default {};
+
 	}
 
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/ImportAutoConfigurationTests.java

@@ -38,11 +38,25 @@ public class ImportAutoConfigurationTests {
 
 	@Test
 	public void multipleAnnotationsShouldMergeCorrectly() {
-		testConfigImports(Config.class);
-		testConfigImports(AnotherConfig.class);
+		assertThat(getImportedConfigBeans(Config.class)).containsExactly("ConfigA",
+				"ConfigB", "ConfigC", "ConfigD");
+		assertThat(getImportedConfigBeans(AnotherConfig.class)).containsExactly("ConfigA",
+				"ConfigB", "ConfigC", "ConfigD");
 	}
 
-	private void testConfigImports(Class<?> config) {
+	@Test
+	public void classesAsAnAlias() throws Exception {
+		assertThat(getImportedConfigBeans(AnotherConfigUsingClasses.class))
+				.containsExactly("ConfigA", "ConfigB", "ConfigC", "ConfigD");
+	}
+
+	@Test
+	public void excluding() throws Exception {
+		assertThat(getImportedConfigBeans(ExcludingConfig.class))
+				.containsExactly("ConfigA", "ConfigB", "ConfigD");
+	}
+
+	private List<String> getImportedConfigBeans(Class<?> config) {
 		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
 				config);
 		String shortName = ClassUtils.getShortName(ImportAutoConfigurationTests.class);
@@ -54,9 +68,8 @@ public class ImportAutoConfigurationTests {
 				orderedConfigBeans.add(shortBeanName.substring(beginIndex));
 			}
 		}
-		assertThat(orderedConfigBeans).containsExactly("ConfigA", "ConfigB", "ConfigC",
-				"ConfigD");
 		context.close();
+		return orderedConfigBeans;
 	}
 
 	@ImportAutoConfiguration({ ConfigD.class, ConfigB.class })
@@ -71,6 +84,19 @@ public class ImportAutoConfigurationTests {
 
 	}
 
+	@MetaImportAutoConfiguration
+	@ImportAutoConfiguration(classes = { ConfigB.class, ConfigD.class })
+	static class AnotherConfigUsingClasses {
+
+	}
+
+	@ImportAutoConfiguration(classes = { ConfigD.class,
+			ConfigB.class }, exclude = ConfigC.class)
+	@MetaImportAutoConfiguration
+	static class ExcludingConfig {
+
+	}
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@ImportAutoConfiguration({ ConfigC.class, ConfigA.class })
 	@interface MetaImportAutoConfiguration {

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/jdbc/JdbcTest.java

@@ -31,6 +31,7 @@ import org.springframework.boot.test.autoconfigure.filter.TypeExcludeFilters;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
 import org.springframework.context.annotation.ComponentScan;
+import org.springframework.core.annotation.AliasFor;
 import org.springframework.test.context.BootstrapWith;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -95,4 +96,11 @@ public @interface JdbcTest {
 	 */
 	ComponentScan.Filter[] excludeFilters() default {};
 
+	/**
+	 * Auto-configuration exclusions that should be applied for this test.
+	 * @return auto-configuration exclusions to apply
+	 */
+	@AliasFor(annotation = ImportAutoConfiguration.class, attribute = "exclude")
+	Class<?>[] excludeAutoConfiguration() default {};
+
 }

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/json/JsonTest.java

@@ -32,6 +32,7 @@ import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
 import org.springframework.boot.test.json.GsonTester;
 import org.springframework.boot.test.json.JacksonTester;
 import org.springframework.context.annotation.ComponentScan.Filter;
+import org.springframework.core.annotation.AliasFor;
 import org.springframework.test.context.BootstrapWith;
 
 /**
@@ -90,4 +91,11 @@ public @interface JsonTest {
 	 */
 	Filter[] excludeFilters() default {};
 
+	/**
+	 * Auto-configuration exclusions that should be applied for this test.
+	 * @return auto-configuration exclusions to apply
+	 */
+	@AliasFor(annotation = ImportAutoConfiguration.class, attribute = "exclude")
+	Class<?>[] excludeAutoConfiguration() default {};
+
 }

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/orm/jpa/DataJpaTest.java

@@ -33,6 +33,7 @@ import org.springframework.boot.test.autoconfigure.properties.PropertyMapping;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
 import org.springframework.context.annotation.ComponentScan.Filter;
+import org.springframework.core.annotation.AliasFor;
 import org.springframework.test.context.BootstrapWith;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -106,4 +107,11 @@ public @interface DataJpaTest {
 	 */
 	Filter[] excludeFilters() default {};
 
+	/**
+	 * Auto-configuration exclusions that should be applied for this test.
+	 * @return auto-configuration exclusions to apply
+	 */
+	@AliasFor(annotation = ImportAutoConfiguration.class, attribute = "exclude")
+	Class<?>[] excludeAutoConfiguration() default {};
+
 }

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/client/RestClientTest.java

@@ -115,4 +115,11 @@ public @interface RestClientTest {
 	 */
 	ComponentScan.Filter[] excludeFilters() default {};
 
+	/**
+	 * Auto-configuration exclusions that should be applied for this test.
+	 * @return auto-configuration exclusions to apply
+	 */
+	@AliasFor(annotation = ImportAutoConfiguration.class, attribute = "exclude")
+	Class<?>[] excludeAutoConfiguration() default {};
+
 }

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/WebMvcTest.java

@@ -132,4 +132,11 @@ public @interface WebMvcTest {
 	@AliasFor(annotation = AutoConfigureMockMvc.class, attribute = "secure")
 	boolean secure() default true;
 
+	/**
+	 * Auto-configuration exclusions that should be applied for this test.
+	 * @return auto-configuration exclusions to apply
+	 */
+	@AliasFor(annotation = ImportAutoConfiguration.class, attribute = "exclude")
+	Class<?>[] excludeAutoConfiguration() default {};
+
 }