Register reflection hints for HttpExchange annotations

See gh-29271

spring-web/src/main/java/org/springframework/web/service/annotation/HttpExchange.java

@@ -22,6 +22,7 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import org.springframework.aot.hint.annotation.Reflective;
 import org.springframework.core.annotation.AliasFor;
 import org.springframework.web.bind.annotation.Mapping;
 
@@ -105,6 +106,7 @@ import org.springframework.web.bind.annotation.Mapping;
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 @Mapping
+@Reflective(HttpExchangeReflectiveProcessor.class)
 public @interface HttpExchange {
 
 	/**

spring-web/src/main/java/org/springframework/web/service/annotation/HttpExchangeReflectiveProcessor.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2002-2022 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.web.service.annotation;
+
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Method;
+import java.lang.reflect.Parameter;
+
+import org.springframework.aot.hint.BindingReflectionHintsRegistrar;
+import org.springframework.aot.hint.ExecutableMode;
+import org.springframework.aot.hint.ReflectionHints;
+import org.springframework.aot.hint.annotation.ReflectiveProcessor;
+import org.springframework.core.MethodParameter;
+import org.springframework.web.bind.annotation.RequestBody;
+
+/**
+ * {@link ReflectiveProcessor} implementation for {@link HttpExchange @HttpExchange}
+ * and annotated methods. On top of registering reflection hints for invoking
+ * the annotated method, this implementation handles reflection-based
+ * binding for return types and parameters annotated with {@link RequestBody}.
+ *
+ * @author Sebastien Deleuze
+ * @since 6.0
+ */
+class HttpExchangeReflectiveProcessor implements ReflectiveProcessor {
+
+	private final BindingReflectionHintsRegistrar bindingRegistrar = new BindingReflectionHintsRegistrar();
+
+	@Override
+	public void registerReflectionHints(ReflectionHints hints, AnnotatedElement element) {
+		if (element instanceof Method method) {
+			registerMethodHints(hints, method);
+		}
+	}
+
+	protected void registerMethodHints(ReflectionHints hints, Method method) {
+		hints.registerMethod(method, ExecutableMode.INVOKE);
+		for (Parameter parameter : method.getParameters()) {
+			registerParameterTypeHints(hints, MethodParameter.forParameter(parameter));
+		}
+		registerReturnTypeHints(hints, MethodParameter.forExecutable(method, -1));
+	}
+
+	protected void registerParameterTypeHints(ReflectionHints hints, MethodParameter methodParameter) {
+		if (methodParameter.hasParameterAnnotation(RequestBody.class)) {
+			this.bindingRegistrar.registerReflectionHints(hints, methodParameter.getGenericParameterType());
+		}
+	}
+
+	protected void registerReturnTypeHints(ReflectionHints hints, MethodParameter returnTypeParameter) {
+		if (!void.class.equals(returnTypeParameter.getParameterType())) {
+			this.bindingRegistrar.registerReflectionHints(hints, returnTypeParameter.getGenericParameterType());
+		}
+	}
+
+}