Invoke handleEmptyBody if there is no content-type

Closes gh-30522

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/AbstractMessageConverterMethodArgumentResolver.java

@@ -23,6 +23,7 @@ import java.lang.annotation.Annotation;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Optional;
@@ -38,6 +39,7 @@ import org.springframework.core.log.LogFormatUtils;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpOutputMessage;
 import org.springframework.http.HttpRequest;
 import org.springframework.http.InvalidMediaTypeException;
 import org.springframework.http.MediaType;
@@ -170,7 +172,6 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 		EmptyBodyCheckingHttpInputMessage message = null;
 		try {
 			message = new EmptyBodyCheckingHttpInputMessage(inputMessage);
-
 			for (HttpMessageConverter<?> converter : this.messageConverters) {
 				Class<HttpMessageConverter<?>> converterType = (Class<HttpMessageConverter<?>>) converter.getClass();
 				GenericHttpMessageConverter<?> genericConverter =
@@ -190,6 +191,10 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 					break;
 				}
 			}
+			if (body == NO_VALUE && noContentType && !message.hasBody()) {
+				body = getAdvice().handleEmptyBody(
+						null, message, parameter, targetType, NoContentTypeHttpMessageConverter.class);
+			}
 		}
 		catch (IOException ex) {
 			throw new HttpMessageNotReadableException("I/O error while reading input message", ex, inputMessage);
@@ -201,8 +206,7 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 		}
 
 		if (body == NO_VALUE) {
-			if (httpMethod == null || !SUPPORTED_METHODS.contains(httpMethod) ||
-					(noContentType && !message.hasBody())) {
+			if (httpMethod == null || !SUPPORTED_METHODS.contains(httpMethod) || (noContentType && !message.hasBody())) {
 				return null;
 			}
 			throw new HttpMediaTypeNotSupportedException(contentType,
@@ -354,4 +358,38 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 		}
 	}
 
+
+	/**
+	 * Placeholder HttpMessageConverter type to pass to RequestBodyAdvice if there
+	 * is no content-type and no content. In that case, we may not find a converter,
+	 * but RequestBodyAdvice have a chance to provide it via handleEmptyBody.
+	 */
+	private static class NoContentTypeHttpMessageConverter implements HttpMessageConverter<String> {
+
+		@Override
+		public boolean canRead(Class<?> clazz, @Nullable MediaType mediaType) {
+			return false;
+		}
+
+		@Override
+		public boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType) {
+			return false;
+		}
+
+		@Override
+		public List<MediaType> getSupportedMediaTypes() {
+			return Collections.emptyList();
+		}
+
+		@Override
+		public String read(Class<? extends String> clazz, HttpInputMessage inputMessage) {
+			throw new UnsupportedOperationException();
+		}
+
+		@Override
+		public void write(String s, @Nullable MediaType contentType, HttpOutputMessage outputMessage) {
+			throw new UnsupportedOperationException();
+		}
+	}
+
 }

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapterTests.java

@@ -25,6 +25,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.groovy.util.Maps;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -45,6 +46,8 @@ import org.springframework.lang.Nullable;
 import org.springframework.ui.Model;
 import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.bind.annotation.SessionAttributes;
 import org.springframework.web.context.support.StaticWebApplicationContext;
 import org.springframework.web.method.HandlerMethod;
@@ -109,7 +112,7 @@ public class RequestMappingHandlerAdapterTests {
 
 	@Test
 	public void cacheControlWithoutSessionAttributes() throws Exception {
-		HandlerMethod handlerMethod = handlerMethod(new SimpleController(), "handle");
+		HandlerMethod handlerMethod = handlerMethod(new TestController(), "handle");
 		this.handlerAdapter.setCacheSeconds(100);
 		this.handlerAdapter.afterPropertiesSet();
 
@@ -197,7 +200,7 @@ public class RequestMappingHandlerAdapterTests {
 		this.webAppContext.registerSingleton("maa", ModelAttributeAdvice.class);
 		this.webAppContext.refresh();
 
-		HandlerMethod handlerMethod = handlerMethod(new SimpleController(), "handle");
+		HandlerMethod handlerMethod = handlerMethod(new TestController(), "handle");
 		this.handlerAdapter.afterPropertiesSet();
 		ModelAndView mav = this.handlerAdapter.handle(this.request, this.response, handlerMethod);
 
@@ -210,7 +213,7 @@ public class RequestMappingHandlerAdapterTests {
 		this.webAppContext.registerPrototype("maa", ModelAttributeAdvice.class);
 		this.webAppContext.refresh();
 
-		HandlerMethod handlerMethod = handlerMethod(new SimpleController(), "handle");
+		HandlerMethod handlerMethod = handlerMethod(new TestController(), "handle");
 		this.handlerAdapter.afterPropertiesSet();
 		Map<String, Object> model1 = this.handlerAdapter.handle(this.request, this.response, handlerMethod).getModel();
 		Map<String, Object> model2 = this.handlerAdapter.handle(this.request, this.response, handlerMethod).getModel();
@@ -226,7 +229,7 @@ public class RequestMappingHandlerAdapterTests {
 		this.webAppContext.setParent(parent);
 		this.webAppContext.refresh();
 
-		HandlerMethod handlerMethod = handlerMethod(new SimpleController(), "handle");
+		HandlerMethod handlerMethod = handlerMethod(new TestController(), "handle");
 		this.handlerAdapter.afterPropertiesSet();
 		ModelAndView mav = this.handlerAdapter.handle(this.request, this.response, handlerMethod);
 
@@ -240,7 +243,7 @@ public class RequestMappingHandlerAdapterTests {
 		this.webAppContext.registerSingleton("manupa", ModelAttributeNotUsedPackageAdvice.class);
 		this.webAppContext.refresh();
 
-		HandlerMethod handlerMethod = handlerMethod(new SimpleController(), "handle");
+		HandlerMethod handlerMethod = handlerMethod(new TestController(), "handle");
 		this.handlerAdapter.afterPropertiesSet();
 		ModelAndView mav = this.handlerAdapter.handle(this.request, this.response, handlerMethod);
 
@@ -249,9 +252,7 @@ public class RequestMappingHandlerAdapterTests {
 		assertThat(mav.getModel().get("attr3")).isNull();
 	}
 
-	// SPR-10859
-
-	@Test
+	@Test // gh-15486
 	public void responseBodyAdvice() throws Exception {
 		List<HttpMessageConverter<?>> converters = new ArrayList<>();
 		converters.add(new MappingJackson2HttpMessageConverter());
@@ -263,7 +264,7 @@ public class RequestMappingHandlerAdapterTests {
 		this.request.addHeader("Accept", MediaType.APPLICATION_JSON_VALUE);
 		this.request.setParameter("c", "callback");
 
-		HandlerMethod handlerMethod = handlerMethod(new SimpleController(), "handleBadRequest");
+		HandlerMethod handlerMethod = handlerMethod(new TestController(), "handleBadRequest");
 		this.handlerAdapter.afterPropertiesSet();
 		this.handlerAdapter.handle(this.request, this.response, handlerMethod);
 
@@ -271,6 +272,19 @@ public class RequestMappingHandlerAdapterTests {
 		assertThat(this.response.getContentAsString()).isEqualTo("{\"status\":400,\"message\":\"body\"}");
 	}
 
+	@Test // gh-30522
+	public void responseBodyAdviceWithEmptyBody() throws Exception {
+		this.webAppContext.registerBean("rba", EmptyBodyAdvice.class);
+		this.webAppContext.refresh();
+
+		HandlerMethod handlerMethod = handlerMethod(new TestController(), "handleBody", Map.class);
+		this.handlerAdapter.afterPropertiesSet();
+		this.handlerAdapter.handle(this.request, this.response, handlerMethod);
+
+		assertThat(this.response.getStatus()).isEqualTo(200);
+		assertThat(this.response.getContentAsString()).isEqualTo("Body: {foo=bar}");
+	}
+
 	private HandlerMethod handlerMethod(Object handler, String methodName, Class<?>... paramTypes) throws Exception {
 		Method method = handler.getClass().getDeclaredMethod(methodName, paramTypes);
 		return new InvocableHandlerMethod(handler, method);
@@ -284,7 +298,7 @@ public class RequestMappingHandlerAdapterTests {
 
 
 	@SuppressWarnings("unused")
-	private static class SimpleController {
+	private static class TestController {
 
 		@ModelAttribute
 		public void addAttributes(Model model) {
@@ -296,14 +310,17 @@ public class RequestMappingHandlerAdapterTests {
 		}
 
 		public ResponseEntity<Map<String, String>> handleWithResponseEntity() {
-			return new ResponseEntity<>(Collections.singletonMap(
-					"foo", "bar"), HttpStatus.OK);
+			return new ResponseEntity<>(Collections.singletonMap("foo", "bar"), HttpStatus.OK);
 		}
 
 		public ResponseEntity<String> handleBadRequest() {
 			return new ResponseEntity<>("body", HttpStatus.BAD_REQUEST);
 		}
 
+		@ResponseBody
+		public String handleBody(@Nullable @RequestBody Map<String, String> body) {
+			return "Body: " + body;
+		}
 	}
 
 
@@ -360,6 +377,7 @@ public class RequestMappingHandlerAdapterTests {
 		}
 	}
 
+
 	/**
 	 * This class additionally implements {@link RequestBodyAdvice} solely for the purpose
 	 * of verifying that controller advice implementing both {@link ResponseBodyAdvice}
@@ -368,7 +386,8 @@ public class RequestMappingHandlerAdapterTests {
 	 * @see <a href="https://github.com/spring-projects/spring-framework/pull/22638">gh-22638</a>
 	 */
 	@ControllerAdvice
-	private static class ResponseCodeSuppressingAdvice extends AbstractMappingJacksonResponseBodyAdvice implements RequestBodyAdvice {
+	private static class ResponseCodeSuppressingAdvice
+			extends AbstractMappingJacksonResponseBodyAdvice implements RequestBodyAdvice {
 
 		@Override
 		protected void beforeBodyWriteInternal(MappingJacksonValue bodyContainer, MediaType contentType,
@@ -405,12 +424,42 @@ public class RequestMappingHandlerAdapterTests {
 		}
 
 		@Override
-		public Object handleEmptyBody(@Nullable Object body, HttpInputMessage inputMessage, MethodParameter parameter,
+		public Object handleEmptyBody(Object body, HttpInputMessage inputMessage, MethodParameter parameter,
 				Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
 
 			return "default value for empty body";
 		}
+	}
+
+
+	@ControllerAdvice
+	private static class EmptyBodyAdvice implements RequestBodyAdvice {
+
+		@Override
+		public boolean supports(MethodParameter param, Type targetType, Class<? extends HttpMessageConverter<?>> type) {
+			return true;
+		}
+
+		@Override
+		public HttpInputMessage beforeBodyRead(HttpInputMessage message, MethodParameter param,
+				Type targetType, Class<? extends HttpMessageConverter<?>> type) {
+
+			throw new UnsupportedOperationException();
+		}
 
+		@Override
+		public Object afterBodyRead(Object body, HttpInputMessage message, MethodParameter param,
+				Type targetType, Class<? extends HttpMessageConverter<?>> type) {
+
+			throw new UnsupportedOperationException();
+		}
+
+		@Override
+		public Object handleEmptyBody(Object body, HttpInputMessage message, MethodParameter param,
+				Type targetType, Class<? extends HttpMessageConverter<?>> type) {
+
+			return Maps.of("foo", "bar");
+		}
 	}
 
 }