Add @Name support to the annotation processor

Update the `ConfigurationMetadataAnnotationProcessor` so that `@Name`
annotated parameters generate the correct meta-data.

Closes gh-22492

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/ConfigurationMetadataAnnotationProcessor.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -81,6 +81,8 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 	static final String READ_OPERATION_ANNOTATION = "org.springframework.boot.actuate."
 			+ "endpoint.annotation.ReadOperation";
 
+	static final String NAME_ANNOTATION = "org.springframework.boot.context.properties.bind.Name";
+
 	private static final Set<String> SUPPORTED_OPTIONS = Collections
 			.unmodifiableSet(Collections.singleton(ADDITIONAL_METADATA_LOCATIONS_OPTION));
 
@@ -118,6 +120,10 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 		return READ_OPERATION_ANNOTATION;
 	}
 
+	protected String nameAnnotation() {
+		return NAME_ANNOTATION;
+	}
+
 	@Override
 	public SourceVersion getSupportedSourceVersion() {
 		return SourceVersion.latestSupported();
@@ -136,7 +142,7 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 		this.metadataEnv = new MetadataGenerationEnvironment(env, configurationPropertiesAnnotation(),
 				nestedConfigurationPropertyAnnotation(), deprecatedConfigurationPropertyAnnotation(),
 				constructorBindingAnnotation(), defaultValueAnnotation(), endpointAnnotation(),
-				readOperationAnnotation());
+				readOperationAnnotation(), nameAnnotation());
 	}
 
 	@Override

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/MetadataGenerationEnvironment.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -95,10 +95,12 @@ class MetadataGenerationEnvironment {
 
 	private final String readOperationAnnotation;
 
+	private final String nameAnnotation;
+
 	MetadataGenerationEnvironment(ProcessingEnvironment environment, String configurationPropertiesAnnotation,
 			String nestedConfigurationPropertyAnnotation, String deprecatedConfigurationPropertyAnnotation,
 			String constructorBindingAnnotation, String defaultValueAnnotation, String endpointAnnotation,
-			String readOperationAnnotation) {
+			String readOperationAnnotation, String nameAnnotation) {
 		this.typeUtils = new TypeUtils(environment);
 		this.elements = environment.getElementUtils();
 		this.messager = environment.getMessager();
@@ -110,6 +112,7 @@ class MetadataGenerationEnvironment {
 		this.defaultValueAnnotation = defaultValueAnnotation;
 		this.endpointAnnotation = endpointAnnotation;
 		this.readOperationAnnotation = readOperationAnnotation;
+		this.nameAnnotation = nameAnnotation;
 	}
 
 	private static FieldValuesParser resolveFieldValuesParser(ProcessingEnvironment env) {
@@ -275,6 +278,10 @@ class MetadataGenerationEnvironment {
 		return getAnnotation(element, this.readOperationAnnotation);
 	}
 
+	AnnotationMirror getNameAnnotation(Element element) {
+		return getAnnotation(element, this.nameAnnotation);
+	}
+
 	boolean hasNullableAnnotation(Element element) {
 		return getAnnotation(element, NULLABLE_ANNOTATION) != null;
 	}

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/PropertyDescriptorResolver.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -22,6 +22,7 @@ import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.NestingKind;
 import javax.lang.model.element.TypeElement;
@@ -76,7 +77,7 @@ class PropertyDescriptorResolver {
 			TypeElementMembers members, ExecutableElement constructor) {
 		Map<String, PropertyDescriptor<?>> candidates = new LinkedHashMap<>();
 		constructor.getParameters().forEach((parameter) -> {
-			String name = parameter.getSimpleName().toString();
+			String name = getParameterName(parameter);
 			TypeMirror propertyType = parameter.asType();
 			ExecutableElement getter = members.getPublicGetter(name, propertyType);
 			ExecutableElement setter = members.getPublicSetter(name, propertyType);
@@ -87,6 +88,14 @@ class PropertyDescriptorResolver {
 		return candidates.values().stream();
 	}
 
+	private String getParameterName(VariableElement parameter) {
+		AnnotationMirror nameAnnotation = this.environment.getNameAnnotation(parameter);
+		if (nameAnnotation != null) {
+			return (String) this.environment.getAnnotationElementValues(nameAnnotation).get("value");
+		}
+		return parameter.getSimpleName().toString();
+	}
+
 	Stream<PropertyDescriptor<?>> resolveJavaBeanProperties(TypeElement type, ExecutableElement factoryMethod,
 			TypeElementMembers members) {
 		// First check if we have regular java bean properties there

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/ImmutableNameAnnotationPropertiesTests.java

+/*
+ * 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.configurationprocessor;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.configurationprocessor.metadata.ConfigurationMetadata;
+import org.springframework.boot.configurationprocessor.metadata.Metadata;
+import org.springframework.boot.configurationsample.immutable.ImmutableNameAnnotationProperties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Metadata generation tests for immutable properties using {@code @Name}.
+ *
+ * @author Phillip Webb
+ */
+public class ImmutableNameAnnotationPropertiesTests extends AbstractMetadataGenerationTests {
+
+	@Test
+	void immutableNameAnnotationProperties() {
+		ConfigurationMetadata metadata = compile(ImmutableNameAnnotationProperties.class);
+		assertThat(metadata).has(Metadata.withProperty("named.import", String.class)
+				.fromSource(ImmutableNameAnnotationProperties.class));
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/MetadataGenerationEnvironmentFactory.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -38,7 +38,8 @@ class MetadataGenerationEnvironmentFactory implements Function<ProcessingEnviron
 				TestConfigurationMetadataAnnotationProcessor.CONSTRUCTOR_BINDING_ANNOTATION,
 				TestConfigurationMetadataAnnotationProcessor.DEFAULT_VALUE_ANNOTATION,
 				TestConfigurationMetadataAnnotationProcessor.ENDPOINT_ANNOTATION,
-				TestConfigurationMetadataAnnotationProcessor.READ_OPERATION_ANNOTATION);
+				TestConfigurationMetadataAnnotationProcessor.READ_OPERATION_ANNOTATION,
+				TestConfigurationMetadataAnnotationProcessor.NAME_ANNOTATION);
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/PropertyDescriptorResolverTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -36,6 +36,7 @@ import org.springframework.boot.configurationprocessor.test.RoundEnvironmentTest
 import org.springframework.boot.configurationprocessor.test.TestableAnnotationProcessor;
 import org.springframework.boot.configurationsample.immutable.ImmutableClassConstructorBindingProperties;
 import org.springframework.boot.configurationsample.immutable.ImmutableMultiConstructorProperties;
+import org.springframework.boot.configurationsample.immutable.ImmutableNameAnnotationProperties;
 import org.springframework.boot.configurationsample.immutable.ImmutableSimpleProperties;
 import org.springframework.boot.configurationsample.lombok.LombokExplicitProperties;
 import org.springframework.boot.configurationsample.lombok.LombokSimpleDataProperties;
@@ -144,6 +145,12 @@ class PropertyDescriptorResolverTests {
 				properties((stream) -> assertThat(stream).element(0).isInstanceOf(JavaBeanPropertyDescriptor.class)));
 	}
 
+	@Test
+	void propertiesWithNameAnnotationParameter() throws IOException {
+		process(ImmutableNameAnnotationProperties.class,
+				propertyNames((stream) -> assertThat(stream).containsExactly("import")));
+	}
+
 	private BiConsumer<TypeElement, MetadataGenerationEnvironment> properties(
 			Consumer<Stream<PropertyDescriptor<?>>> stream) {
 		return (element, metadataEnv) -> {

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/test/TestConfigurationMetadataAnnotationProcessor.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -55,6 +55,8 @@ public class TestConfigurationMetadataAnnotationProcessor extends ConfigurationM
 
 	public static final String READ_OPERATION_ANNOTATION = "org.springframework.boot.configurationsample.ReadOperation";
 
+	public static final String NAME_ANNOTATION = "org.springframework.boot.configurationsample.Name";
+
 	private ConfigurationMetadata metadata;
 
 	private final File outputLocation;
@@ -98,6 +100,11 @@ public class TestConfigurationMetadataAnnotationProcessor extends ConfigurationM
 		return READ_OPERATION_ANNOTATION;
 	}
 
+	@Override
+	protected String nameAnnotation() {
+		return NAME_ANNOTATION;
+	}
+
 	@Override
 	protected ConfigurationMetadata writeMetaData() throws Exception {
 		super.writeMetaData();

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/Name.java

+/*
+ * 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.configurationsample;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Alternative to Spring Boot's {@code @Name} for testing (removes the need for a
+ * dependency on the real annotation).
+ *
+ * @author Phillip Webb
+ */
+@Target(ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface Name {
+
+	String value();
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/immutable/ImmutableNameAnnotationProperties.java

+/*
+ * 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.configurationsample.immutable;
+
+import org.springframework.boot.configurationsample.ConfigurationProperties;
+import org.springframework.boot.configurationsample.ConstructorBinding;
+import org.springframework.boot.configurationsample.Name;
+
+/**
+ * Immutable properties making use of {@code @Name}.
+ *
+ * @author Phillip Webb
+ */
+@ConfigurationProperties("named")
+@ConstructorBinding
+public class ImmutableNameAnnotationProperties {
+
+	private String imports;
+
+	public ImmutableNameAnnotationProperties(@Name("import") String imports) {
+		this.imports = imports;
+	}
+
+	public String getImports() {
+		return this.imports;
+	}
+
+}