Don't cause early FactoryBean instantiation

Update ConfigurationPropertiesBindingPostProcessor to use
`getBeansOfType` with `allowEagerInit=false` rather than `getBean`.

This prevents FactoryBeans from being instantiated early when their
type is not known.

Fixed spring-projectsgh-1365

Author: philwebb

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

@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.util.Iterator;
+import java.util.Map;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanCreationException;
@@ -203,15 +204,10 @@ public void destroy() throws Exception {
 	}
 
 	private PropertySources deducePropertySources() {
-		try {
-			PropertySourcesPlaceholderConfigurer configurer = this.beanFactory
-					.getBean(PropertySourcesPlaceholderConfigurer.class);
-			PropertySources propertySources = configurer.getAppliedPropertySources();
+		PropertySourcesPlaceholderConfigurer configurer = getSinglePropertySourcesPlaceholderConfigurer();
+		if (configurer != null) {
 			// Flatten the sources into a single list so they can be iterated
-			return new FlatPropertySources(propertySources);
-		}
-		catch (NoSuchBeanDefinitionException ex) {
-			// Continue if no PropertySourcesPlaceholderConfigurer bean
+			return new FlatPropertySources(configurer.getAppliedPropertySources());
 		}
 
 		if (this.environment instanceof ConfigurableEnvironment) {
@@ -224,6 +220,20 @@ private PropertySources deducePropertySources() {
 		return new MutablePropertySources();
 	}
 
+	private PropertySourcesPlaceholderConfigurer getSinglePropertySourcesPlaceholderConfigurer() {
+		// Take care not to cause early instantiation of all FactoryBeans
+		if (this.beanFactory instanceof ListableBeanFactory) {
+			ListableBeanFactory listableBeanFactory = (ListableBeanFactory) this.beanFactory;
+			Map<String, PropertySourcesPlaceholderConfigurer> beans = listableBeanFactory
+					.getBeansOfType(PropertySourcesPlaceholderConfigurer.class, false,
+							false);
+			if (beans.size() == 1) {
+				return beans.values().iterator().next();
+			}
+		}
+		return null;
+	}
+
 	private <T> T getOptionalBean(String name, Class<T> type) {
 		try {
 			return this.beanFactory.getBean(name, type);

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

@@ -21,8 +21,13 @@
 
 import org.junit.After;
 import org.junit.Test;
+import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.beans.factory.support.AbstractBeanDefinition;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
 import org.springframework.boot.test.EnvironmentTestUtils;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -36,8 +41,10 @@
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 /**
@@ -141,6 +148,26 @@ public void testValueBindingForDefaults() throws Exception {
 				equalTo("foo"));
 	}
 
+	@Test
+	public void configurationPropertiesWithFactoryBean() throws Exception {
+		ConfigurationPropertiesWithFactoryBean.factoryBeanInit = false;
+		this.context = new AnnotationConfigApplicationContext() {
+			@Override
+			protected void onRefresh() throws BeansException {
+				assertFalse("Init too early",
+						ConfigurationPropertiesWithFactoryBean.factoryBeanInit);
+				super.onRefresh();
+			}
+		};
+		this.context.register(ConfigurationPropertiesWithFactoryBean.class);
+		GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
+		beanDefinition.setBeanClass(FactoryBeanTester.class);
+		beanDefinition.setAutowireMode(AbstractBeanDefinition.AUTOWIRE_BY_TYPE);
+		this.context.registerBeanDefinition("test", beanDefinition);
+		this.context.refresh();
+		assertTrue("No init", ConfigurationPropertiesWithFactoryBean.factoryBeanInit);
+	}
+
 	@Configuration
 	@EnableConfigurationProperties
 	public static class TestConfigurationWithValidatingSetter {
@@ -299,4 +326,37 @@ public static PropertySourcesPlaceholderConfigurer configurer() {
 
 	}
 
+	@Configuration
+	@EnableConfigurationProperties
+	public static class ConfigurationPropertiesWithFactoryBean {
+
+		public static boolean factoryBeanInit;
+
+	}
+
+	@SuppressWarnings("rawtypes")
+	// Must be a raw type
+	static class FactoryBeanTester implements FactoryBean, InitializingBean {
+
+		@Override
+		public Object getObject() throws Exception {
+			return Object.class;
+		}
+
+		@Override
+		public Class<?> getObjectType() {
+			return null;
+		}
+
+		@Override
+		public boolean isSingleton() {
+			return true;
+		}
+
+		@Override
+		public void afterPropertiesSet() throws Exception {
+			ConfigurationPropertiesWithFactoryBean.factoryBeanInit = true;
+		}
+
+	}
 }