Add bind method to ConfigurationProperties bean definition

This commit reworks the configuration properties registrar to use
RootBeanDefinition and a standard attribute rather than relying on
a package private sub-class. This allows other components to inspect
the metadata if necessary.

Closes gh-27821

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -21,7 +21,7 @@ import org.springframework.beans.factory.HierarchicalBeanFactory;
 import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.boot.context.properties.ConfigurationPropertiesBean.BindMethod;
 import org.springframework.core.annotation.MergedAnnotation;
 import org.springframework.core.annotation.MergedAnnotations;
@@ -89,12 +89,24 @@ final class ConfigurationPropertiesBeanRegistrar {
 	}
 
 	private BeanDefinition createBeanDefinition(String beanName, Class<?> type) {
-		if (BindMethod.forType(type) == BindMethod.VALUE_OBJECT) {
-			return new ConfigurationPropertiesValueObjectBeanDefinition(this.beanFactory, beanName, type);
+		BindMethod bindMethod = BindMethod.forType(type);
+		RootBeanDefinition definition = new RootBeanDefinition(type);
+		definition.setAttribute(BindMethod.class.getName(), bindMethod);
+		if (bindMethod == BindMethod.VALUE_OBJECT) {
+			definition.setInstanceSupplier(() -> createValueObject(beanName, type));
 		}
-		GenericBeanDefinition definition = new GenericBeanDefinition();
-		definition.setBeanClass(type);
 		return definition;
 	}
 
+	private Object createValueObject(String beanName, Class<?> beanType) {
+		ConfigurationPropertiesBean bean = ConfigurationPropertiesBean.forValueObject(beanType, beanName);
+		ConfigurationPropertiesBinder binder = ConfigurationPropertiesBinder.get(this.beanFactory);
+		try {
+			return binder.bindOrCreate(bean);
+		}
+		catch (Exception ex) {
+			throw new ConfigurationPropertiesBindException(bean, ex);
+		}
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -94,8 +94,8 @@ public class ConfigurationPropertiesBindingPostProcessor
 	}
 
 	private boolean hasBoundValueObject(String beanName) {
-		return this.registry.containsBeanDefinition(beanName) && this.registry
-				.getBeanDefinition(beanName) instanceof ConfigurationPropertiesValueObjectBeanDefinition;
+		return this.registry.containsBeanDefinition(beanName) && BindMethod.VALUE_OBJECT
+				.equals(this.registry.getBeanDefinition(beanName).getAttribute(BindMethod.class.getName()));
 	}
 
 	/**
@@ -108,7 +108,7 @@ public class ConfigurationPropertiesBindingPostProcessor
 		Assert.notNull(registry, "Registry must not be null");
 		if (!registry.containsBeanDefinition(BEAN_NAME)) {
 			BeanDefinition definition = BeanDefinitionBuilder
-					.genericBeanDefinition(ConfigurationPropertiesBindingPostProcessor.class,
+					.rootBeanDefinition(ConfigurationPropertiesBindingPostProcessor.class,
 							ConfigurationPropertiesBindingPostProcessor::new)
 					.getBeanDefinition();
 			definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);

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

@@ -1,56 +0,0 @@
-/*
- * Copyright 2012-2020 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
- *
- *      https://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 org.springframework.beans.factory.BeanFactory;
-import org.springframework.beans.factory.config.BeanDefinition;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
-
-/**
- * {@link BeanDefinition} that is used for registering
- * {@link ConfigurationProperties @ConfigurationProperties} value object beans that are
- * bound at creation time.
- *
- * @author Stephane Nicoll
- * @author Madhura Bhave
- * @author Phillip Webb
- */
-final class ConfigurationPropertiesValueObjectBeanDefinition extends GenericBeanDefinition {
-
-	private final BeanFactory beanFactory;
-
-	private final String beanName;
-
-	ConfigurationPropertiesValueObjectBeanDefinition(BeanFactory beanFactory, String beanName, Class<?> beanClass) {
-		this.beanFactory = beanFactory;
-		this.beanName = beanName;
-		setBeanClass(beanClass);
-		setInstanceSupplier(this::createBean);
-	}
-
-	private Object createBean() {
-		ConfigurationPropertiesBean bean = ConfigurationPropertiesBean.forValueObject(getBeanClass(), this.beanName);
-		ConfigurationPropertiesBinder binder = ConfigurationPropertiesBinder.get(this.beanFactory);
-		try {
-			return binder.bindOrCreate(bean);
-		}
-		catch (Exception ex) {
-			throw new ConfigurationPropertiesBindException(bean, ex);
-		}
-	}
-
-}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -16,12 +16,16 @@
 
 package org.springframework.boot.context.properties;
 
+import java.util.function.Consumer;
+
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.boot.context.properties.ConfigurationPropertiesBean.BindMethod;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
@@ -70,15 +74,23 @@ class ConfigurationPropertiesBeanRegistrarTests {
 		String beanName = "valuecp-" + ValueObjectConfigurationProperties.class.getName();
 		this.registrar.register(ValueObjectConfigurationProperties.class);
 		BeanDefinition definition = this.registry.getBeanDefinition(beanName);
-		assertThat(definition).isInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
+		assertThat(definition).satisfies(configurationPropertiesBeanDefinition(BindMethod.VALUE_OBJECT));
 	}
 
 	@Test
-	void registerWhenNotValueObjectRegistersGenericBeanDefinition() {
+	void registerWhenNotValueObjectRegistersRootBeanDefinitionWithJavaBeanBindMethod() {
 		String beanName = MultiConstructorBeanConfigurationProperties.class.getName();
 		this.registrar.register(MultiConstructorBeanConfigurationProperties.class);
 		BeanDefinition definition = this.registry.getBeanDefinition(beanName);
-		assertThat(definition).isInstanceOf(GenericBeanDefinition.class);
+		assertThat(definition).satisfies(configurationPropertiesBeanDefinition(BindMethod.JAVA_BEAN));
+	}
+
+	private Consumer<BeanDefinition> configurationPropertiesBeanDefinition(BindMethod bindMethod) {
+		return (definition) -> {
+			assertThat(definition).isExactlyInstanceOf(RootBeanDefinition.class);
+			assertThat(definition.hasAttribute(BindMethod.class.getName())).isTrue();
+			assertThat(definition.getAttribute(BindMethod.class.getName())).isEqualTo(bindMethod);
+		};
 	}
 
 	@ConfigurationProperties(prefix = "beancp")

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -17,12 +17,14 @@
 package org.springframework.boot.context.properties;
 
 import java.io.IOException;
+import java.util.function.Consumer;
 
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.boot.context.properties.ConfigurationPropertiesBean.BindMethod;
 import org.springframework.boot.context.properties.scan.combined.c.CombinedConfiguration;
 import org.springframework.boot.context.properties.scan.combined.d.OtherCombinedConfiguration;
 import org.springframework.boot.context.properties.scan.valid.ConfigurationPropertiesScanConfiguration;
@@ -54,9 +56,9 @@ class ConfigurationPropertiesScanRegistrarTests {
 				"foo-org.springframework.boot.context.properties.scan.valid.ConfigurationPropertiesScanConfiguration$FooProperties");
 		BeanDefinition barDefinition = this.beanFactory.getBeanDefinition(
 				"bar-org.springframework.boot.context.properties.scan.valid.ConfigurationPropertiesScanConfiguration$BarProperties");
-		assertThat(bingDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
-		assertThat(fooDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
-		assertThat(barDefinition).isExactlyInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
+		assertThat(bingDefinition).satisfies(configurationPropertiesBeanDefinition(BindMethod.JAVA_BEAN));
+		assertThat(fooDefinition).satisfies(configurationPropertiesBeanDefinition(BindMethod.JAVA_BEAN));
+		assertThat(barDefinition).satisfies(configurationPropertiesBeanDefinition(BindMethod.VALUE_OBJECT));
 	}
 
 	@Test
@@ -67,7 +69,7 @@ class ConfigurationPropertiesScanRegistrarTests {
 				getAnnotationMetadata(ConfigurationPropertiesScanConfiguration.TestConfiguration.class), beanFactory);
 		BeanDefinition fooDefinition = beanFactory.getBeanDefinition(
 				"foo-org.springframework.boot.context.properties.scan.valid.ConfigurationPropertiesScanConfiguration$FooProperties");
-		assertThat(fooDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+		assertThat(fooDefinition).isExactlyInstanceOf(RootBeanDefinition.class);
 	}
 
 	@Test
@@ -86,11 +88,11 @@ class ConfigurationPropertiesScanRegistrarTests {
 				"b.first-org.springframework.boot.context.properties.scan.valid.b.BScanConfiguration$BFirstProperties");
 		BeanDefinition bSecondDefinition = beanFactory.getBeanDefinition(
 				"b.second-org.springframework.boot.context.properties.scan.valid.b.BScanConfiguration$BSecondProperties");
-		assertThat(aDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+		assertThat(aDefinition).satisfies(configurationPropertiesBeanDefinition(BindMethod.JAVA_BEAN));
 		// Constructor injection
-		assertThat(bFirstDefinition).isExactlyInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
+		assertThat(bFirstDefinition).satisfies(configurationPropertiesBeanDefinition(BindMethod.VALUE_OBJECT));
 		// Post-processing injection
-		assertThat(bSecondDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+		assertThat(bSecondDefinition).satisfies(configurationPropertiesBeanDefinition(BindMethod.JAVA_BEAN));
 	}
 
 	@Test
@@ -110,6 +112,14 @@ class ConfigurationPropertiesScanRegistrarTests {
 		assertThat(beanFactory.getBeanDefinitionCount()).isEqualTo(0);
 	}
 
+	private Consumer<BeanDefinition> configurationPropertiesBeanDefinition(BindMethod bindMethod) {
+		return (definition) -> {
+			assertThat(definition).isExactlyInstanceOf(RootBeanDefinition.class);
+			assertThat(definition.hasAttribute(BindMethod.class.getName())).isTrue();
+			assertThat(definition.getAttribute(BindMethod.class.getName())).isEqualTo(bindMethod);
+		};
+	}
+
 	private AnnotationMetadata getAnnotationMetadata(Class<?> source) throws IOException {
 		return new SimpleMetadataReaderFactory().getMetadataReader(source.getName()).getAnnotationMetadata();
 	}

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

@@ -16,12 +16,15 @@
 
 package org.springframework.boot.context.properties;
 
+import java.util.function.Consumer;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.boot.context.properties.ConfigurationPropertiesBean.BindMethod;
 import org.springframework.core.type.AnnotationMetadata;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -51,27 +54,27 @@ class EnableConfigurationPropertiesRegistrarTests {
 	}
 
 	@Test
-	void typeWithDefaultConstructorShouldRegisterGenericBeanDefinition() {
+	void typeWithDefaultConstructorShouldRegisterRootBeanDefinition() {
 		register(TestConfiguration.class);
-		BeanDefinition beanDefinition = this.beanFactory
+		BeanDefinition definition = this.beanFactory
 				.getBeanDefinition("foo-" + getClass().getName() + "$FooProperties");
-		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+		assertThat(definition).satisfies(configurationPropertiesBeanDefinition(BindMethod.JAVA_BEAN));
 	}
 
 	@Test
 	void typeWithConstructorBindingShouldRegisterConfigurationPropertiesBeanDefinition() {
 		register(TestConfiguration.class);
-		BeanDefinition beanDefinition = this.beanFactory
+		BeanDefinition definition = this.beanFactory
 				.getBeanDefinition("bar-" + getClass().getName() + "$BarProperties");
-		assertThat(beanDefinition).isExactlyInstanceOf(ConfigurationPropertiesValueObjectBeanDefinition.class);
+		assertThat(definition).satisfies(configurationPropertiesBeanDefinition(BindMethod.VALUE_OBJECT));
 	}
 
 	@Test
 	void typeWithMultipleConstructorsShouldRegisterGenericBeanDefinition() {
 		register(TestConfiguration.class);
-		BeanDefinition beanDefinition = this.beanFactory
+		BeanDefinition definition = this.beanFactory
 				.getBeanDefinition("bing-" + getClass().getName() + "$BingProperties");
-		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition.class);
+		assertThat(definition).satisfies(configurationPropertiesBeanDefinition(BindMethod.JAVA_BEAN));
 	}
 
 	@Test
@@ -97,6 +100,14 @@ class EnableConfigurationPropertiesRegistrarTests {
 		}
 	}
 
+	private Consumer<BeanDefinition> configurationPropertiesBeanDefinition(BindMethod bindMethod) {
+		return (definition) -> {
+			assertThat(definition).isExactlyInstanceOf(RootBeanDefinition.class);
+			assertThat(definition.hasAttribute(BindMethod.class.getName())).isTrue();
+			assertThat(definition.getAttribute(BindMethod.class.getName())).isEqualTo(bindMethod);
+		};
+	}
+
 	private void register(Class<?> configuration) {
 		AnnotationMetadata metadata = AnnotationMetadata.introspect(configuration);
 		this.registrar.registerBeanDefinitions(metadata, this.beanFactory);

spring-boot-project/spring-boot/src/test/kotlin/org/springframework/boot/context/properties/KotlinConfigurationPropertiesBeanRegistrarTests.kt

@@ -3,7 +3,7 @@ package org.springframework.boot.context.properties
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.support.DefaultListableBeanFactory
-import org.springframework.beans.factory.support.GenericBeanDefinition
+import org.springframework.beans.factory.support.RootBeanDefinition
 
 /**
  * Tests for `ConfigurationPropertiesBeanRegistrar`.
@@ -18,11 +18,11 @@ class KotlinConfigurationPropertiesBeanRegistrarTests {
 	private val registrar = ConfigurationPropertiesBeanRegistrar(beanFactory)
 
 	@Test
-	fun `type with default constructor should register generic bean definition`() {
+	fun `type with default constructor should register root bean definition`() {
 		this.registrar.register(FooProperties::class.java)
 		val beanDefinition = this.beanFactory.getBeanDefinition(
 				"foo-org.springframework.boot.context.properties.KotlinConfigurationPropertiesBeanRegistrarTests\$FooProperties")
-		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition::class.java)
+		assertThat(beanDefinition).isExactlyInstanceOf(RootBeanDefinition::class.java)
 	}
 
 	@Test
@@ -30,16 +30,17 @@ class KotlinConfigurationPropertiesBeanRegistrarTests {
 		this.registrar.register(BarProperties::class.java)
 		val beanDefinition = this.beanFactory.getBeanDefinition(
 				"bar-org.springframework.boot.context.properties.KotlinConfigurationPropertiesBeanRegistrarTests\$BarProperties")
-		assertThat(beanDefinition).isExactlyInstanceOf(
-				ConfigurationPropertiesValueObjectBeanDefinition::class.java)
+		assertThat(beanDefinition.hasAttribute(ConfigurationPropertiesBean.BindMethod::class.java.name)).isTrue()
+		assertThat(beanDefinition.getAttribute(ConfigurationPropertiesBean.BindMethod::class.java.name))
+			.isEqualTo(ConfigurationPropertiesBean.BindMethod.VALUE_OBJECT)
 	}
 
 	@Test
-	fun `type with no primary constructor should register generic bean definition`() {
+	fun `type with no primary constructor should register root bean definition`() {
 		this.registrar.register(BingProperties::class.java)
 		val beanDefinition = this.beanFactory.getBeanDefinition(
 				"bing-org.springframework.boot.context.properties.KotlinConfigurationPropertiesBeanRegistrarTests\$BingProperties")
-		assertThat(beanDefinition).isExactlyInstanceOf(GenericBeanDefinition::class.java)
+		assertThat(beanDefinition).isExactlyInstanceOf(RootBeanDefinition::class.java)
 	}
 
 	@ConfigurationProperties(prefix = "foo")