Merge branch 'SPR-10534'

* SPR-10534:
  Add support for DeferredImportSelector
  Support for @conditional configuration
  Extend AnnotationMetadata and MethodMetadata

Author: philwebb

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -24,11 +24,9 @@
 import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.BeanNameGenerator;
-import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.env.Environment;
 import org.springframework.core.env.EnvironmentCapable;
 import org.springframework.core.env.StandardEnvironment;
-import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.util.Assert;
 
 /**
@@ -39,6 +37,7 @@
  * @author Juergen Hoeller
  * @author Chris Beams
  * @author Sam Brannen
+ * @author Phillip Webb
  * @since 3.0
  * @see AnnotationConfigApplicationContext#register
  */
@@ -134,12 +133,9 @@ public void registerBean(Class<?> annotatedClass, Class<? extends Annotation>...
 
 	public void registerBean(Class<?> annotatedClass, String name, Class<? extends Annotation>... qualifiers) {
 		AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(annotatedClass);
-		AnnotationMetadata metadata = abd.getMetadata();
-		if (metadata.isAnnotated(Profile.class.getName())) {
-			AnnotationAttributes profile = MetadataUtils.attributesFor(metadata, Profile.class);
-			if (!this.environment.acceptsProfiles(profile.getStringArray("value"))) {
-				return;
-			}
+		if (ConditionalAnnotationHelper.shouldSkip(abd, this.registry,
+				this.environment, this.beanNameGenerator)) {
+			return;
 		}
 		ScopeMetadata scopeMetadata = this.scopeMetadataResolver.resolveScopeMetadata(abd);
 		abd.setScope(scopeMetadata.getScopeName());

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -52,6 +52,7 @@
  * @author Mark Fisher
  * @author Juergen Hoeller
  * @author Chris Beams
+ * @author Phillip Webb
  * @since 2.5
  * @see AnnotationConfigApplicationContext#scan
  * @see org.springframework.stereotype.Component
@@ -298,6 +299,10 @@ protected void registerBeanDefinition(BeanDefinitionHolder definitionHolder, Bea
 	 * bean definition has been found for the specified name
 	 */
 	protected boolean checkCandidate(String beanName, BeanDefinition beanDefinition) throws IllegalStateException {
+		if (ConditionalAnnotationHelper.shouldSkip(beanDefinition, getRegistry(),
+				getEnvironment(), this.beanNameGenerator)) {
+			return false;
+		}
 		if (!this.registry.containsBeanDefinition(beanName)) {
 			return true;
 		}

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

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2002-2013 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
+ *
+ *      http://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 org.springframework.context.annotation;
+
+import org.jruby.internal.runtime.methods.MethodMethod;
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+import org.springframework.core.type.AnnotationMetadata;
+
+/**
+ * A single {@code condition} that must be {@linkplain #matches matched} in order
+ * for a component to be registered.
+ *
+ * <p>Conditions are checked immediately before a component bean-definition is due to be
+ * registered and are free to veto registration based on any criteria that can be
+ * determined at that point.
+ *
+ * <p>Conditions must follow the same restrictions as {@link BeanFactoryPostProcessor}
+ * and take care to never interact with bean instances.
+ *
+ * @author Phillip Webb
+ * @since 4.0
+ * @see Conditional
+ * @see ConditionContext
+ */
+public interface Condition {
+
+	/**
+	 * Determine if the condition matches.
+	 * @param context the condition context
+	 * @param metadata meta-data of the {@link AnnotationMetadata class} or
+	 *        {@link MethodMethod method} being checked.
+	 * @return {@code true} if the condition matches and the component can be registered
+	 *         or {@code false} to veto registration.
+	 */
+	boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata);
+
+}

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

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2002-2013 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
+ *
+ *      http://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 org.springframework.context.annotation;
+
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.core.env.Environment;
+import org.springframework.core.io.ResourceLoader;
+
+/**
+ * Context information for use by {@link Condition}s.
+ *
+ * @author Phillip Webb
+ * @since 4.0
+ */
+public interface ConditionContext {
+
+	/**
+	 * Returns the {@link BeanDefinitionRegistry} that will hold the bean definition
+	 * should the condition match.
+	 * @return the registry (never {@code null})
+	 */
+	BeanDefinitionRegistry getRegistry();
+
+	/**
+	 * Return the {@link Environment} for which the current application is running or
+	 * {@code null} if no environment is available.
+	 * @return the environment or {@code null}
+	 */
+	Environment getEnvironment();
+
+	/**
+	 * Returns the {@link ConfigurableListableBeanFactory} that will hold the bean
+	 * definition should the condition match. If a
+	 * {@link ConfigurableListableBeanFactory} is unavailable an
+	 * {@link IllegalStateException} will be thrown.
+	 * @return the bean factory
+	 * @throws IllegalStateException if the bean factory could not be obtained
+	 */
+	ConfigurableListableBeanFactory getBeanFactory() throws IllegalStateException;
+
+	/**
+	 * Returns the {@link ResourceLoader} currently being used or {@code null} if the
+	 * resource loader cannot be obtained.
+	 * @return a resource loader or {@code null}
+	 */
+	ResourceLoader getResourceLoader();
+
+	/**
+	 * Returns the {@link ClassLoader} that should be used to load additional classes
+	 * or {@code null} if the default classloader should be used.
+	 * @return the classloader or {@code null}
+	 */
+	ClassLoader getClassLoader();
+
+}

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

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2002-2013 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
+ *
+ *      http://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 org.springframework.context.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that a component is is only eligible for registration when all
+ * {@linkplain #value() specified conditions} match.
+ *
+ * <p>A <em>condition</em> is any state that can be determined programmatically
+ * immediately before the bean is due to be created (see {@link Condition} for details).
+ *
+ * <p>The {@code @Conditional} annotation may be used in any of the following ways:
+ * <ul>
+ * <li>as a type-level annotation on any class directly or indirectly annotated with
+ * {@code @Component}, including {@link Configuration @Configuration} classes</li>
+ * <li>as a meta-annotation, for the purpose of composing custom stereotype
+ * annotations</li>
+ * <li>as a method-level annotation on any {@link Bean @Bean} method</li>
+ * </ul>
+ *
+ * <p>If a {@code @Configuration} class is marked with {@code @Conditional}, all of the
+ * {@code @Bean} methods and {@link Import @Import} annotations associated with that class
+ * will be subject to the conditions.
+ *
+ * @author Phillip Webb
+ * @since 4.0
+ * @see Condition
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ ElementType.TYPE, ElementType.METHOD })
+public @interface Conditional {
+
+	/**
+	 * All {@link Condition}s that must {@linkplain Condition#matches match} in order for
+	 * the component to be registered.
+	 */
+	Class<? extends Condition>[] value();
+
+}