Add RequestBody resolver and minor improvements

Support for RequestBody arguments.
List supported arguments on HttpExchange.
Improve null handling.

See gh-28386

spring-web/src/test/java/org/springframework/web/service/invoker/HttpMethodArgumentResolverTests.java

@@ -22,6 +22,7 @@ import org.springframework.http.HttpMethod;
 import org.springframework.web.service.annotation.GetExchange;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 
 /**
@@ -44,14 +45,18 @@ public class HttpMethodArgumentResolverTests {
 	}
 
 	@Test
-	void ignoreOtherArgumentTypes() {
-		this.service.execute("test");
-		assertThat(getActualMethod()).isEqualTo(HttpMethod.GET);
+	void notHttpMethod() {
+		assertThatIllegalStateException()
+				.isThrownBy(() -> this.service.executeNotHttpMethod("test"))
+				.withMessage("Could not resolve parameter [0] in " +
+						"public abstract void org.springframework.web.service.invoker." +
+						"HttpMethodArgumentResolverTests$Service.executeNotHttpMethod(java.lang.String): " +
+						"No suitable resolver");
 	}
 
 	@Test
 	void ignoreNull() {
-		this.service.execute((HttpMethod) null);
+		this.service.execute(null);
 		assertThat(getActualMethod()).isEqualTo(HttpMethod.GET);
 	}
 
@@ -66,7 +71,7 @@ public class HttpMethodArgumentResolverTests {
 		void execute(HttpMethod method);
 
 		@GetExchange
-		void execute(String test);
+		void executeNotHttpMethod(String test);
 
 	}
 

spring-web/src/test/java/org/springframework/web/service/invoker/RequestBodyArgumentResolverTests.java

@@ -0,0 +1,141 @@
+/*
+ * 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.invoker;
+
+import io.reactivex.rxjava3.core.Completable;
+import io.reactivex.rxjava3.core.Single;
+import org.junit.jupiter.api.Test;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.service.annotation.GetExchange;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+
+
+/**
+ * Unit tests for {@link RequestBodyArgumentResolver}.
+ *
+ * @author Rossen Stoyanchev
+ */
+public class RequestBodyArgumentResolverTests {
+
+	private final TestHttpClientAdapter client = new TestHttpClientAdapter();
+
+	private final Service service = HttpServiceProxyFactory.builder(this.client).build().createClient(Service.class);
+
+
+	@Test
+	void stringBody() {
+		String body = "bodyValue";
+		this.service.execute(body);
+
+		assertThat(getRequestValues().getBodyValue()).isEqualTo(body);
+		assertThat(getRequestValues().getBody()).isNull();
+	}
+
+	@Test
+	void monoBody() {
+		Mono<String> bodyMono = Mono.just("bodyValue");
+		this.service.executeMono(bodyMono);
+
+		assertThat(getRequestValues().getBodyValue()).isNull();
+		assertThat(getRequestValues().getBody()).isSameAs(bodyMono);
+		assertThat(getRequestValues().getBodyElementType()).isEqualTo(new ParameterizedTypeReference<String>() {});
+	}
+
+	@Test
+	void singleBody() {
+		String bodyValue = "bodyValue";
+		this.service.executeSingle(Single.just(bodyValue));
+
+		assertThat(getRequestValues().getBodyValue()).isNull();
+		assertThat(getRequestValues().getBodyElementType()).isEqualTo(new ParameterizedTypeReference<String>() {});
+
+		Publisher<?> body = getRequestValues().getBody();
+		assertThat(body).isNotNull();
+		assertThat(((Mono<String>) body).block()).isEqualTo(bodyValue);
+	}
+
+	@Test
+	void monoVoid() {
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> this.service.executeMonoVoid(Mono.empty()))
+				.withMessage("Async type for @RequestBody should produce value(s)");
+	}
+
+	@Test
+	void completable() {
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> this.service.executeCompletable(Completable.complete()))
+				.withMessage("Async type for @RequestBody should produce value(s)");
+	}
+
+	@Test
+	void notRequestBody() {
+		assertThatIllegalStateException()
+				.isThrownBy(() -> this.service.executeNotRequestBody("value"))
+				.withMessage("Could not resolve parameter [0] in " +
+						"public abstract void org.springframework.web.service.invoker." +
+						"RequestBodyArgumentResolverTests$Service.executeNotRequestBody(java.lang.String): " +
+						"No suitable resolver");
+	}
+
+	@Test
+	void ignoreNull() {
+		this.service.execute(null);
+
+		assertThat(getRequestValues().getBodyValue()).isNull();
+		assertThat(getRequestValues().getBody()).isNull();
+
+		this.service.executeMono(null);
+
+		assertThat(getRequestValues().getBodyValue()).isNull();
+		assertThat(getRequestValues().getBody()).isNull();
+	}
+
+	private HttpRequestValues getRequestValues() {
+		return this.client.getRequestValues();
+	}
+
+
+	private interface Service {
+
+		@GetExchange
+		void execute(@RequestBody String body);
+
+		@GetExchange
+		void executeMono(@RequestBody Mono<String> body);
+
+		@GetExchange
+		void executeSingle(@RequestBody Single<String> body);
+
+		@GetExchange
+		void executeMonoVoid(@RequestBody Mono<Void> body);
+
+		@GetExchange
+		void executeCompletable(@RequestBody Completable body);
+
+		@GetExchange
+		void executeNotRequestBody(String body);
+	}
+
+}

spring-web/src/test/java/org/springframework/web/service/invoker/UrlArgumentResolverTests.java

@@ -23,14 +23,15 @@ import org.junit.jupiter.api.Test;
 import org.springframework.web.service.annotation.GetExchange;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 
 /**
- * Unit tests for {@link HttpUrlArgumentResolver}.
+ * Unit tests for {@link UrlArgumentResolver}.
  *
  * @author Rossen Stoyanchev
  */
-public class HttpUrlArgumentResolverTests {
+public class UrlArgumentResolverTests {
 
 	private final TestHttpClientAdapter client = new TestHttpClientAdapter();
 
@@ -46,6 +47,22 @@ public class HttpUrlArgumentResolverTests {
 		assertThat(getRequestValues().getUriTemplate()).isNull();
 	}
 
+	@Test
+	void notUrl() {
+		assertThatIllegalStateException()
+				.isThrownBy(() -> this.service.executeNotUri("test"))
+				.withMessage("Could not resolve parameter [0] in " +
+						"public abstract void org.springframework.web.service.invoker." +
+						"UrlArgumentResolverTests$Service.executeNotUri(java.lang.String): " +
+						"No suitable resolver");
+	}
+
+	@Test
+	void ignoreNull() {
+		this.service.execute(null);
+		assertThat(getRequestValues().getUri()).isNull();
+	}
+
 	private HttpRequestValues getRequestValues() {
 		return this.client.getRequestValues();
 	}
@@ -56,6 +73,8 @@ public class HttpUrlArgumentResolverTests {
 		@GetExchange("/path")
 		void execute(URI uri);
 
+		@GetExchange
+		void executeNotUri(String other);
 	}
 
 }