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

@@ -1,5 +1,5 @@
 /*
- * 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

@@ -1,5 +1,5 @@
 /*
- * 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

@@ -1,5 +1,5 @@
 /*
- * 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