@bean provides autowireCandidate flag (analogous to XML definitions)

Issue: SPR-16204

Author: jhoeller

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -251,6 +251,14 @@
 	 */
 	Autowire autowire() default Autowire.NO;
 
+	/**
+	 * Is this bean a candidate for getting autowired into some other bean?
+	 * <p>Default is {@code true}; set this to {@code false} for internal delegates
+	 * that are not meant to get in the way of beans of the same type in other places.
+	 * @since 5.1
+	 */
+	boolean autowireCandidate() default true;
+
 	/**
 	 * The optional name of a method to call on the bean instance during initialization.
 	 * Not commonly used, given that the method may be called programmatically directly

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

@@ -232,6 +232,11 @@ private void loadBeanDefinitionsForBeanMethod(BeanMethod beanMethod) {
 			beanDef.setAutowireMode(autowire.value());
 		}
 
+		boolean autowireCandidate = bean.getBoolean("autowireCandidate");
+		if (!autowireCandidate) {
+			beanDef.setAutowireCandidate(false);
+		}
+
 		String initMethodName = bean.getString("initMethod");
 		if (StringUtils.hasText(initMethodName)) {
 			beanDef.setInitMethodName(initMethodName);

spring-context/src/test/java/org/springframework/context/annotation/configuration/BeanAnnotationAttributePropagationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -18,6 +18,7 @@
 
 import org.junit.Test;
 
+import org.springframework.beans.factory.annotation.Autowire;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
@@ -41,9 +42,30 @@
  * correctly into the resulting BeanDefinition
  *
  * @author Chris Beams
+ * @author Juergen Hoeller
  */
 public class BeanAnnotationAttributePropagationTests {
 
+	@Test
+	public void autowireMetadataIsPropagated() {
+		@Configuration class Config {
+			@Bean(autowire=Autowire.BY_TYPE) Object foo() { return null; }
+		}
+
+		assertEquals("autowire mode was not propagated",
+				AbstractBeanDefinition.AUTOWIRE_BY_TYPE, beanDef(Config.class).getAutowireMode());
+	}
+
+	@Test
+	public void autowireCandidateMetadataIsPropagated() {
+		@Configuration class Config {
+			@Bean(autowireCandidate=false) Object foo() { return null; }
+		}
+
+		assertFalse("autowire candidate flag was not propagated",
+				beanDef(Config.class).isAutowireCandidate());
+	}
+
 	@Test
 	public void initMethodMetadataIsPropagated() {
 		@Configuration class Config {
@@ -138,7 +160,7 @@ public void eagerBeanOverridesDefaultLazyConfiguration() {
 
 	@Test
 	public void eagerConfigurationProducesEagerBeanDefinitions() {
-		@Lazy(false) @Configuration class Config { // will probably never happen, doesn't make much sense
+		@Lazy(false) @Configuration class Config {  // will probably never happen, doesn't make much sense
 			@Bean Object foo() { return null; }
 		}