Support multiple RequestMapping and HttpExchange annotations

Author: youssef3wi

spring-web/src/main/java/org/springframework/web/bind/annotation/RequestMapping.java

@@ -18,6 +18,7 @@
 
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
@@ -80,6 +81,7 @@
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 @Mapping
+@Repeatable(RequestMappings.class)
 @Reflective(ControllerMappingReflectiveProcessor.class)
 public @interface RequestMapping {
 

spring-web/src/main/java/org/springframework/web/bind/annotation/RequestMappings.java

@@ -0,0 +1,25 @@
+package org.springframework.web.bind.annotation;
+
+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;
+
+/**
+ * Container annotation that aggregates several {@link RequestMapping} annotations.
+ *
+ * <p>Can be used natively, declaring several nested {@link RequestMapping} annotations.
+ * Can also be used in conjunction with Java 8's support for repeatable annotations,
+ * where {@link RequestMapping} can simply be declared several times on the same method,
+ * implicitly generating this container annotation.
+ *
+ * @see RequestMapping
+ * @since 6.2
+ */
+@Target({ElementType.TYPE, ElementType.METHOD})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface RequestMappings {
+	RequestMapping[] value();
+}

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/AbstractHandlerMethodMapping.java

@@ -31,6 +31,7 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
+import org.springframework.lang.NonNull;
 import reactor.core.publisher.Mono;
 
 import org.springframework.aop.support.AopUtils;
@@ -168,7 +169,7 @@ public void afterPropertiesSet() {
 	/**
 	 * Scan beans in the ApplicationContext, detect and register handler methods.
 	 * @see #isHandler(Class)
-	 * @see #getMappingForMethod(Method, Class)
+	 * @see #getListMappingsForMethod(Method, Class)
 	 * @see #handlerMethodsInitialized(Map)
 	 */
 	protected void initHandlerMethods() {
@@ -204,22 +205,24 @@ protected void detectHandlerMethods(final Object handler) {
 
 		if (handlerType != null) {
 			final Class<?> userType = ClassUtils.getUserClass(handlerType);
-			Map<Method, T> methods = MethodIntrospector.selectMethods(userType,
-					(MethodIntrospector.MetadataLookup<T>) method -> getMappingForMethod(method, userType));
+			Map<Method, List<T>> methods = MethodIntrospector.selectMethods(userType,
+					(MethodIntrospector.MetadataLookup<List<T>>) method -> getListMappingsForMethod(method, userType));
 			if (logger.isTraceEnabled()) {
 				logger.trace(formatMappings(userType, methods));
 			}
 			else if (mappingsLogger.isDebugEnabled()) {
 				mappingsLogger.debug(formatMappings(userType, methods));
 			}
-			methods.forEach((method, mapping) -> {
+			methods.forEach((method, mappings) -> {
 				Method invocableMethod = AopUtils.selectInvocableMethod(method, userType);
-				registerHandlerMethod(handler, invocableMethod, mapping);
+				for (T mapping : mappings) {
+					registerHandlerMethod(handler, invocableMethod, mapping);
+				}
 			});
 		}
 	}
 
-	private String formatMappings(Class<?> userType, Map<Method, T> methods) {
+	private String formatMappings(Class<?> userType, Map<Method, List<T>> methods) {
 		String packageName = ClassUtils.getPackageName(userType);
 		String formattedType = (StringUtils.hasText(packageName) ?
 				Arrays.stream(packageName.split("\\."))
@@ -423,15 +426,15 @@ protected CorsConfiguration getCorsConfiguration(Object handler, ServerWebExchan
 	protected abstract boolean isHandler(Class<?> beanType);
 
 	/**
-	 * Provide the mapping for a handler method. A method for which no
+	 * Provide the list of mappings for a handler method. A method for which no
 	 * mapping can be provided is not a handler method.
 	 * @param method the method to provide a mapping for
 	 * @param handlerType the handler type, possibly a subtype of the method's
 	 * declaring class
-	 * @return the mapping, or {@code null} if the method is not mapped
+	 * @return the list of mappings, or an empty list if the method is not mapped
 	 */
-	@Nullable
-	protected abstract T getMappingForMethod(Method method, Class<?> handlerType);
+	@NonNull
+	protected abstract List<T> getListMappingsForMethod(Method method, Class<?> handlerType);
 
 	/**
 	 * Return the request mapping paths that are not patterns.

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/RequestMappingHandlerMapping.java

@@ -20,6 +20,7 @@
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Method;
 import java.lang.reflect.Parameter;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -34,6 +35,7 @@
 import org.springframework.core.annotation.MergedAnnotations;
 import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
 import org.springframework.core.annotation.RepeatableContainers;
+import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 import org.springframework.stereotype.Controller;
 import org.springframework.util.Assert;
@@ -152,42 +154,59 @@ protected boolean isHandler(Class<?> beanType) {
 
 	/**
 	 * Uses type-level and method-level {@link RequestMapping @RequestMapping}
-	 * and {@link HttpExchange @HttpExchange} annotations to create the
-	 * {@link RequestMappingInfo}.
-	 * @return the created {@code RequestMappingInfo}, or {@code null} if the method
+	 * and {@link HttpExchange @HttpExchange} annotations to create the list
+	 * of {@link RequestMappingInfo}.
+	 * @return the created list of {@code RequestMappingInfo}, or an empty list if the method
 	 * does not have a {@code @RequestMapping} or {@code @HttpExchange} annotation
 	 * @see #getCustomMethodCondition(Method)
 	 * @see #getCustomTypeCondition(Class)
 	 */
 	@Override
-	@Nullable
-	protected RequestMappingInfo getMappingForMethod(Method method, Class<?> handlerType) {
-		RequestMappingInfo info = createRequestMappingInfo(method);
-		if (info != null) {
-			RequestMappingInfo typeInfo = createRequestMappingInfo(handlerType);
-			if (typeInfo != null) {
-				info = typeInfo.combine(info);
+	@NonNull
+	protected List<RequestMappingInfo> getListMappingsForMethod(Method method, Class<?> handlerType) {
+		List<RequestMappingInfo> result = new ArrayList<>();
+		List<RequestMappingInfo> infos = buildListOfRequestMappingInfo(method);
+		if (!infos.isEmpty()) {
+			List<RequestMappingInfo> typeInfos = buildListOfRequestMappingInfo(handlerType);
+			if (!typeInfos.isEmpty()) {
+				List<RequestMappingInfo> requestMappingInfos = new ArrayList<>();
+				for (RequestMappingInfo info : infos) {
+					for (RequestMappingInfo typeInfo : typeInfos) {
+						requestMappingInfos.add(typeInfo.combine(info));
+					}
+				}
+				infos = requestMappingInfos;
 			}
-			if (info.getPatternsCondition().isEmptyPathMapping()) {
-				info = info.mutate().paths("", "/").options(this.config).build();
+			for (RequestMappingInfo info : infos) {
+				if (info.getPatternsCondition().isEmptyPathMapping()) {
+					info = info.mutate().paths("", "/").options(this.config).build();
+				}
+
+				result.add(info);
 			}
-			for (Map.Entry<String, Predicate<Class<?>>> entry : this.pathPrefixes.entrySet()) {
-				if (entry.getValue().test(handlerType)) {
-					String prefix = entry.getKey();
-					if (this.embeddedValueResolver != null) {
-						prefix = this.embeddedValueResolver.resolveStringValue(prefix);
+
+			for (int idx = 0; idx < result.size(); idx++) {
+				RequestMappingInfo info = result.get(idx);
+
+				for (Map.Entry<String, Predicate<Class<?>>> entry : this.pathPrefixes.entrySet()) {
+					if (entry.getValue().test(handlerType)) {
+						String prefix = entry.getKey();
+						if (this.embeddedValueResolver != null) {
+							prefix = this.embeddedValueResolver.resolveStringValue(prefix);
+						}
+						info = RequestMappingInfo.paths(prefix).options(this.config).build().combine(info);
+						result.set(idx, info);
+						break;
 					}
-					info = RequestMappingInfo.paths(prefix).options(this.config).build().combine(info);
-					break;
 				}
 			}
 		}
-		return info;
+		return Collections.unmodifiableList(result);
 	}
 
-	@Nullable
-	private RequestMappingInfo createRequestMappingInfo(AnnotatedElement element) {
-		RequestMappingInfo requestMappingInfo = null;
+	@NonNull
+	private List<RequestMappingInfo> buildListOfRequestMappingInfo(AnnotatedElement element) {
+		List<RequestMappingInfo> requestMappingInfos = new ArrayList<>();
 		RequestCondition<?> customCondition = (element instanceof Class<?> clazz ?
 				getCustomTypeCondition(clazz) : getCustomMethodCondition((Method) element));
 
@@ -200,22 +219,25 @@ private RequestMappingInfo createRequestMappingInfo(AnnotatedElement element) {
 				logger.warn("Multiple @RequestMapping annotations found on %s, but only the first will be used: %s"
 						.formatted(element, requestMappings));
 			}
-			requestMappingInfo = createRequestMappingInfo((RequestMapping) requestMappings.get(0).annotation, customCondition);
+
+			for (AnnotationDescriptor requestMapping : requestMappings) {
+				requestMappingInfos.add(createRequestMappingInfo((RequestMapping) requestMapping.annotation, customCondition));
+			}
 		}
 
 		List<AnnotationDescriptor> httpExchanges = descriptors.stream()
 				.filter(desc -> desc.annotation instanceof HttpExchange).toList();
 		if (!httpExchanges.isEmpty()) {
-			Assert.state(requestMappingInfo == null,
+			Assert.state(requestMappings.isEmpty(),
 					() -> "%s is annotated with @RequestMapping and @HttpExchange annotations, but only one is allowed: %s"
 							.formatted(element, Stream.of(requestMappings, httpExchanges).flatMap(List::stream).toList()));
-			Assert.state(httpExchanges.size() == 1,
-					() -> "Multiple @HttpExchange annotations found on %s, but only one is allowed: %s"
-							.formatted(element, httpExchanges));
-			requestMappingInfo = createRequestMappingInfo((HttpExchange) httpExchanges.get(0).annotation, customCondition);
+
+			for (AnnotationDescriptor httpExchange : httpExchanges) {
+				requestMappingInfos.add(createRequestMappingInfo((HttpExchange) httpExchange.annotation, customCondition));
+			}
 		}
 
-		return requestMappingInfo;
+		return Collections.unmodifiableList(requestMappingInfos);
 	}
 
 	/**

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/HandlerMethodMappingTests.java

@@ -25,6 +25,7 @@
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.springframework.lang.NonNull;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
@@ -200,9 +201,10 @@ protected boolean isHandler(Class<?> beanType) {
 		}
 
 		@Override
-		protected String getMappingForMethod(Method method, Class<?> handlerType) {
+		@NonNull
+		protected List<String> getListMappingsForMethod(Method method, Class<?> handlerType) {
 			String methodName = method.getName();
-			return methodName.startsWith("handler") ? methodName : null;
+			return methodName.startsWith("handler") ? Collections.singletonList(methodName) : Collections.emptyList();
 		}
 
 		@Override

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/RequestMappingInfoHandlerMappingTests.java

@@ -29,6 +29,7 @@
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.springframework.lang.NonNull;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
@@ -523,19 +524,20 @@ protected boolean isHandler(Class<?> beanType) {
 		}
 
 		@Override
-		protected RequestMappingInfo getMappingForMethod(Method method, Class<?> handlerType) {
+		@NonNull
+		protected List<RequestMappingInfo> getListMappingsForMethod(Method method, Class<?> handlerType) {
+			List<RequestMappingInfo> results = new ArrayList<>();
 			RequestMapping annot = AnnotatedElementUtils.findMergedAnnotation(method, RequestMapping.class);
 			if (annot != null) {
 				BuilderConfiguration options = new BuilderConfiguration();
 				options.setPatternParser(getPathPatternParser());
-				return paths(annot.value()).methods(annot.method())
+				results.add(paths(annot.value()).methods(annot.method())
 						.params(annot.params()).headers(annot.headers())
 						.consumes(annot.consumes()).produces(annot.produces())
-						.options(options).build();
-			}
-			else {
-				return null;
+						.options(options).build());
 			}
+
+			return results;
 		}
 	}