Enable @ConfigurationProperties on a @Bean definition

This allows multiple beans of the same type to be bound with
different prefixes. As a side effect you get default binding
if the bean class is itself @ConfigurationProperties.

spring-boot/src/main/java/org/springframework/boot/context/properties/BeanMetaDataStore.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2012-2013 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.boot.context.properties;
+
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.util.ReflectionUtils;
+import org.springframework.util.ReflectionUtils.MethodCallback;
+
+/**
+ * Utility class to memoize <code>@Bean</code> definition meta data during initialization
+ * of the bean factory.
+ * 
+ * @author Dave Syer
+ */
+class BeanMetaDataStore implements BeanFactoryPostProcessor {
+
+	private ConfigurableListableBeanFactory beanFactory;
+
+	private Map<String, MetaData> beans = new HashMap<String, MetaData>();
+
+	@Override
+	public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory)
+			throws BeansException {
+		this.beanFactory = beanFactory;
+		for (String name : beanFactory.getBeanDefinitionNames()) {
+			BeanDefinition definition = beanFactory.getBeanDefinition(name);
+			String method = definition.getFactoryMethodName();
+			String bean = definition.getFactoryBeanName();
+			if (method != null && bean != null) {
+				this.beans.put(name, new MetaData(bean, method));
+			}
+		}
+	}
+
+	public Method findFactoryMethod(String beanName) {
+		if (!this.beans.containsKey(beanName)) {
+			return null;
+		}
+		final AtomicReference<Method> found = new AtomicReference<Method>();
+		MetaData meta = this.beans.get(beanName);
+		final String factory = meta.getMethod();
+		Class<?> type = this.beanFactory.getType(meta.getBean());
+		ReflectionUtils.doWithMethods(type, new MethodCallback() {
+			@Override
+			public void doWith(Method method) throws IllegalArgumentException,
+					IllegalAccessException {
+				if (method.getName().equals(factory)) {
+					found.set(method);
+				}
+			}
+		});
+		return found.get();
+	}
+
+	private static class MetaData {
+
+		private String bean;
+
+		private String method;
+
+		public MetaData(String bean, String method) {
+			this.bean = bean;
+			this.method = method;
+		}
+
+		public String getBean() {
+			return this.bean;
+		}
+
+		public String getMethod() {
+			return this.method;
+		}
+
+	}
+
+}

spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationProperties.java

@@ -29,7 +29,7 @@ import java.lang.annotation.Target;
  * @author Dave Syer
  * @see ConfigurationPropertiesBindingPostProcessor
  */
-@Target(ElementType.TYPE)
+@Target({ ElementType.TYPE, ElementType.METHOD })
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 public @interface ConfigurationProperties {

spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessor.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.context.properties;
 
 import java.io.IOException;
+import java.lang.reflect.Method;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanCreationException;
@@ -74,6 +75,8 @@ public class ConfigurationPropertiesBindingPostProcessor implements BeanPostProc
 	private static final String[] VALIDATOR_CLASSES = { "javax.validation.Validator",
 			"javax.validation.ValidatorFactory" };
 
+	private BeanMetaDataStore beans = new BeanMetaDataStore();
+
 	private PropertySources propertySources;
 
 	private Validator validator;
@@ -132,6 +135,13 @@ public class ConfigurationPropertiesBindingPostProcessor implements BeanPostProc
 		this.conversionService = conversionService;
 	}
 
+	/**
+	 * @param beans the bean meta data to set
+	 */
+	public void setBeanMetaDataStore(BeanMetaDataStore beans) {
+		this.beans = beans;
+	}
+
 	@Override
 	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
 		this.beanFactory = beanFactory;
@@ -277,9 +287,24 @@ public class ConfigurationPropertiesBindingPostProcessor implements BeanPostProc
 		if (annotation != null || bean instanceof ConfigurationPropertiesHolder) {
 			postProcessBeforeInitialization(bean, beanName, annotation);
 		}
+		annotation = maybePostProcessAnnotatedFactoryMethod(bean, beanName);
+		if (annotation != null) {
+			postProcessBeforeInitialization(bean, beanName, annotation);
+		}
 		return bean;
 	}
 
+	private ConfigurationProperties maybePostProcessAnnotatedFactoryMethod(Object bean,
+			String beanName) {
+		Method method = this.beans.findFactoryMethod(beanName);
+		if (method != null) {
+			ConfigurationProperties annotation = AnnotationUtils.findAnnotation(method,
+					ConfigurationProperties.class);
+			return annotation;
+		}
+		return null;
+	}
+
 	@Override
 	public Object postProcessAfterInitialization(Object bean, String beanName)
 			throws BeansException {
@@ -353,7 +378,7 @@ public class ConfigurationPropertiesBindingPostProcessor implements BeanPostProc
 	}
 
 	private ConversionService getDefaultConversionService() {
-		if (!this.initialized && this.beanFactory instanceof ListableBeanFactory) {
+		if (!this.initialized) {
 			for (Converter<?, ?> converter : ((ListableBeanFactory) this.beanFactory)
 					.getBeansOfType(Converter.class).values()) {
 				this.defaultConversionService.addConverter(converter);

spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessorRegistrar.java

@@ -16,9 +16,8 @@
 
 package org.springframework.boot.context.properties;
 
-import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
 import org.springframework.core.type.AnnotationMetadata;
 
@@ -35,14 +34,19 @@ public class ConfigurationPropertiesBindingPostProcessorRegistrar implements
 	public static final String BINDER_BEAN_NAME = ConfigurationPropertiesBindingPostProcessor.class
 			.getName();
 
+	private static final String METADATA_BEAN_NAME = BINDER_BEAN_NAME + ".store";
+
 	@Override
 	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata,
 			BeanDefinitionRegistry registry) {
 		if (!registry.containsBeanDefinition(BINDER_BEAN_NAME)) {
-			BeanDefinition beanDefinition = new RootBeanDefinition(
-					ConfigurationPropertiesBindingPostProcessor.class);
-			registry.registerBeanDefinition(BINDER_BEAN_NAME, beanDefinition);
+			BeanDefinitionBuilder meta = BeanDefinitionBuilder
+					.genericBeanDefinition(BeanMetaDataStore.class);
+			BeanDefinitionBuilder bean = BeanDefinitionBuilder
+					.genericBeanDefinition(ConfigurationPropertiesBindingPostProcessor.class);
+			bean.addPropertyReference("beanMetaDataStore", METADATA_BEAN_NAME);
+			registry.registerBeanDefinition(BINDER_BEAN_NAME, bean.getBeanDefinition());
+			registry.registerBeanDefinition(METADATA_BEAN_NAME, meta.getBeanDefinition());
 		}
 	}
-
 }

spring-boot/src/test/java/org/springframework/boot/context/properties/EnableConfigurationPropertiesTests.java

@@ -370,6 +370,27 @@ public class EnableConfigurationPropertiesTests {
 		assertEquals("value12", bean.mymap.get("key1.key2"));
 	}
 
+	@Test
+	public void testAnnotatedBean() {
+		EnvironmentTestUtils.addEnvironment(this.context, "external.name:bar",
+				"spam.name:foo");
+		this.context.register(TestConfigurationWithAnnotatedBean.class);
+		this.context.refresh();
+		assertEquals("foo", this.context.getBean(External.class).getName());
+	}
+
+	@Configuration
+	@EnableConfigurationProperties
+	public static class TestConfigurationWithAnnotatedBean {
+
+		@Bean
+		@ConfigurationProperties(prefix = "spam")
+		public External testProperties() {
+			return new External();
+		}
+
+	}
+
 	/**
 	 * Strict tests need a known set of properties so we remove system items which may be
 	 * environment specific.