Support *Aware for @componentscan custom filters

Support a limited set of *Aware interfaces for TypeFilters created
via the @componentscan annotation.

Issue: SPR-14009

Author: philwebb

spring-context/src/main/java/org/springframework/context/annotation/ComponentScan.java

@@ -189,6 +189,15 @@
 		 * </table>
 		 * <p>When multiple classes are specified, <em>OR</em> logic is applied
 		 * &mdash; for example, "include types annotated with {@code @Foo} OR {@code @Bar}".
+		 * <p>Custom {@link TypeFilter TypeFilters} may optionally implement any of the
+		 * following {@link org.springframework.beans.factory.Aware Aware} interfaces, and
+		 * their respective methods will be called prior to {@link TypeFilter#match match}:
+		 * <ul>
+		 * <li>{@link org.springframework.context.EnvironmentAware EnvironmentAware}</li>
+		 * <li>{@link org.springframework.beans.factory.BeanFactoryAware BeanFactoryAware}
+		 * <li>{@link org.springframework.beans.factory.BeanClassLoaderAware BeanClassLoaderAware}
+		 * <li>{@link org.springframework.context.ResourceLoaderAware ResourceLoaderAware}
+		 * </ul>
 		 * <p>Specifying zero classes is permitted but will have no effect on component
 		 * scanning.
 		 * @since 4.2

spring-context/src/main/java/org/springframework/context/annotation/ComponentScanAnnotationParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -25,10 +25,17 @@
 import java.util.regex.Pattern;
 
 import org.springframework.beans.BeanUtils;
+import org.springframework.beans.factory.Aware;
+import org.springframework.beans.factory.BeanClassLoaderAware;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.config.BeanDefinitionHolder;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.BeanNameGenerator;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.EnvironmentAware;
+import org.springframework.context.ResourceLoaderAware;
 import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.env.Environment;
 import org.springframework.core.io.ResourceLoader;
@@ -156,7 +163,9 @@ private List<TypeFilter> typeFiltersFor(AnnotationAttributes filterAttributes) {
 				case CUSTOM:
 					Assert.isAssignable(TypeFilter.class, filterClass,
 							"An error occured while processing a @ComponentScan CUSTOM type filter: ");
-					typeFilters.add(BeanUtils.instantiateClass(filterClass, TypeFilter.class));
+					TypeFilter filter = BeanUtils.instantiateClass(filterClass, TypeFilter.class);
+					invokeAwareMethods(filter);
+					typeFilters.add(filter);
 					break;
 				default:
 					throw new IllegalArgumentException("Filter type not supported with Class value: " + filterType);
@@ -179,4 +188,27 @@ private List<TypeFilter> typeFiltersFor(AnnotationAttributes filterAttributes) {
 		return typeFilters;
 	}
 
+	/**
+	 * Invoke {@link ResourceLoaderAware}, {@link BeanClassLoaderAware} and
+	 * {@link BeanFactoryAware} contracts if implemented by the given {@code filter}.
+	 */
+	private void invokeAwareMethods(TypeFilter filter) {
+		if (filter instanceof Aware) {
+			if (filter instanceof EnvironmentAware) {
+				((EnvironmentAware) filter).setEnvironment(this.environment);
+			}
+			if (filter instanceof ResourceLoaderAware) {
+				((ResourceLoaderAware) filter).setResourceLoader(this.resourceLoader);
+			}
+			if (filter instanceof BeanClassLoaderAware) {
+				ClassLoader classLoader = (this.registry instanceof ConfigurableBeanFactory ?
+						((ConfigurableBeanFactory) this.registry).getBeanClassLoader() :
+						this.resourceLoader.getClassLoader());
+				((BeanClassLoaderAware) filter).setBeanClassLoader(classLoader);
+			}
+			if (filter instanceof BeanFactoryAware && this.registry instanceof BeanFactory) {
+				((BeanFactoryAware) filter).setBeanFactory((BeanFactory) this.registry);
+			}
+		}
+	}
 }

spring-context/src/test/java/org/springframework/context/annotation/ComponentScanAnnotationIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -36,15 +36,28 @@
 import org.junit.Test;
 
 import org.springframework.aop.support.AopUtils;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanClassLoaderAware;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.annotation.CustomAutowireConfigurer;
 import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.context.EnvironmentAware;
+import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.annotation.ComponentScan.Filter;
 import org.springframework.context.annotation.ComponentScanParserTests.KustomAnnotationAutowiredBean;
 import org.springframework.context.annotation.componentscan.simple.ClassWithNestedComponents;
 import org.springframework.context.annotation.componentscan.simple.SimpleComponent;
 import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.Environment;
+import org.springframework.core.io.ResourceLoader;
+import org.springframework.core.type.classreading.MetadataReader;
+import org.springframework.core.type.classreading.MetadataReaderFactory;
+import org.springframework.core.type.filter.TypeFilter;
 import org.springframework.tests.context.SimpleMapScope;
 import org.springframework.util.SerializationTestUtils;
 
@@ -177,6 +190,12 @@ public void withCustomTypeFilter() {
 		assertThat(testBean.getDependency(), notNullValue());
 	}
 
+	@Test
+	public void withAwareTypeFilter() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(ComponentScanWithAwareTypeFilter.class);
+		assertTrue(ctx.getEnvironment().acceptsProfiles("the-filter-ran"));
+	}
+
 	@Test
 	public void withScopedProxy() throws IOException, ClassNotFoundException {
 		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
@@ -258,6 +277,47 @@ public void withBasePackagesAndValueAlias() {
 	public static class ComposedAnnotationConfig {
 	}
 
+	public static class AwareTypeFilter implements TypeFilter, EnvironmentAware,
+			ResourceLoaderAware, BeanClassLoaderAware, BeanFactoryAware {
+
+		private BeanFactory beanFactory;
+		private ClassLoader classLoader;
+		private ResourceLoader resourceLoader;
+		private Environment environment;
+
+		@Override
+		public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
+			this.beanFactory = beanFactory;
+		}
+
+		@Override
+		public void setBeanClassLoader(ClassLoader classLoader) {
+			this.classLoader = classLoader;
+		}
+
+		@Override
+		public void setResourceLoader(ResourceLoader resourceLoader) {
+			this.resourceLoader = resourceLoader;
+		}
+
+		@Override
+		public void setEnvironment(Environment environment) {
+			this.environment = environment;
+		}
+
+		@Override
+		public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) {
+			((ConfigurableEnvironment) this.environment).addActiveProfile("the-filter-ran");
+			assertNotNull(this.beanFactory);
+			assertNotNull(this.classLoader);
+			assertNotNull(this.resourceLoader);
+			assertNotNull(this.environment);
+			return false;
+		}
+
+	}
+
+
 }
 
 
@@ -340,6 +400,14 @@ public ComponentScanParserTests.KustomAnnotationAutowiredBean testBean() {
 	}
 }
 
+@Configuration
+@ComponentScan(
+		basePackages = "org.springframework.context.annotation",
+		useDefaultFilters = false,
+		includeFilters = @Filter(type = FilterType.CUSTOM, classes = ComponentScanAnnotationIntegrationTests.AwareTypeFilter.class),
+		lazyInit = true)
+class ComponentScanWithAwareTypeFilter {}
+
 @Configuration
 @ComponentScan(basePackages = "example.scannable",
 		scopedProxy = ScopedProxyMode.INTERFACES,
@@ -384,3 +452,5 @@ class ComponentScanWithMultipleAnnotationIncludeFilters2 {}
 		basePackages = "example.scannable",
 		basePackageClasses = example.scannable._package.class)
 class ComponentScanWithBasePackagesAndValueAlias {}
+
+