Support @HttpExchange for server-side handling

See gh-30980

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

@@ -35,6 +35,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.stereotype.Controller;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 import org.springframework.util.StringValueResolver;
 import org.springframework.web.accept.ContentNegotiationManager;
 import org.springframework.web.bind.annotation.CrossOrigin;
@@ -43,6 +44,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.cors.CorsConfiguration;
 import org.springframework.web.method.HandlerMethod;
+import org.springframework.web.service.annotation.HttpExchange;
 import org.springframework.web.servlet.handler.MatchableHandlerMapping;
 import org.springframework.web.servlet.handler.RequestMatchResult;
 import org.springframework.web.servlet.mvc.condition.AbstractRequestCondition;
@@ -71,6 +73,7 @@ import org.springframework.web.util.pattern.PathPatternParser;
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
  * @author Sam Brannen
+ * @author Olga Maciaszek-Sharma
  * @since 3.1
  */
 public class RequestMappingHandlerMapping extends RequestMappingInfoHandlerMapping
@@ -331,18 +334,27 @@ public class RequestMappingHandlerMapping extends RequestMappingInfoHandlerMappi
 	}
 
 	/**
-	 * Delegates to {@link #createRequestMappingInfo(RequestMapping, RequestCondition)},
-	 * supplying the appropriate custom {@link RequestCondition} depending on whether
+	 * Delegates to {@link #createRequestMappingInfo(RequestMapping, RequestCondition)}
+	 * or {@link #createRequestMappingInfo(HttpExchange, RequestCondition)},
+	 * depending on which annotation is found on the element being processed,
+	 * and supplying the appropriate custom {@link RequestCondition} depending on whether
 	 * the supplied {@code annotatedElement} is a class or method.
 	 * @see #getCustomTypeCondition(Class)
 	 * @see #getCustomMethodCondition(Method)
 	 */
 	@Nullable
 	private RequestMappingInfo createRequestMappingInfo(AnnotatedElement element) {
-		RequestMapping requestMapping = AnnotatedElementUtils.findMergedAnnotation(element, RequestMapping.class);
 		RequestCondition<?> condition = (element instanceof Class<?> clazz ?
 				getCustomTypeCondition(clazz) : getCustomMethodCondition((Method) element));
-		return (requestMapping != null ? createRequestMappingInfo(requestMapping, condition) : null);
+		RequestMapping requestMapping = AnnotatedElementUtils.findMergedAnnotation(element, RequestMapping.class);
+		if(requestMapping != null){
+			return createRequestMappingInfo(requestMapping, condition);
+		}
+		HttpExchange httpExchange = AnnotatedElementUtils.findMergedAnnotation(element, HttpExchange.class);
+		if(httpExchange != null){
+			return createRequestMappingInfo(httpExchange, condition);
+		}
+		return null;
 	}
 
 	/**
@@ -400,6 +412,28 @@ public class RequestMappingHandlerMapping extends RequestMappingInfoHandlerMappi
 		return builder.options(this.config).build();
 	}
 
+	/**
+	 * Create a {@link RequestMappingInfo} from the supplied
+	 * {@link HttpExchange @HttpExchange} annotation, which is either
+	 * a directly declared annotation, a meta-annotation, or the synthesized
+	 * result of merging annotation attributes within an annotation hierarchy.
+	 */
+	protected RequestMappingInfo createRequestMappingInfo(
+			HttpExchange httpExchange,
+			@Nullable RequestCondition<?> customCondition) {
+
+		RequestMappingInfo.Builder builder = RequestMappingInfo
+				.paths(resolveEmbeddedValuesInPatterns(
+						toTextArray(httpExchange.value())))
+				.methods(toMethodArray(httpExchange.method()))
+				.consumes(toTextArray(httpExchange.contentType()))
+				.produces(httpExchange.accept());
+		if (customCondition != null) {
+			builder.customCondition(customCondition);
+		}
+		return builder.options(this.config).build();
+	}
+
 	/**
 	 * Resolve placeholder values in the given array of patterns.
 	 * @return a new array with updated patterns
@@ -417,6 +451,24 @@ public class RequestMappingHandlerMapping extends RequestMappingInfoHandlerMappi
 		}
 	}
 
+
+	private static String[] toTextArray(String string) {
+		if (StringUtils.hasText(string)) {
+			return new String[] { string };
+		}
+		return new String[] {};
+	}
+
+	private static RequestMethod[] toMethodArray(String method) {
+		RequestMethod requestMethod = null;
+		if (StringUtils.hasText(method)) {
+			requestMethod = RequestMethod.resolve(method);
+		}
+		return requestMethod != null ? new RequestMethod[] { requestMethod }
+				: new RequestMethod[] {};
+	}
+
+
 	@Override
 	public void registerMapping(RequestMappingInfo mapping, Object handler, Method method) {
 		super.registerMapping(mapping, handler, method);

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

@@ -47,11 +47,14 @@ import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.context.support.StaticWebApplicationContext;
 import org.springframework.web.method.HandlerTypePredicate;
+import org.springframework.web.service.annotation.HttpExchange;
 import org.springframework.web.servlet.handler.PathPatternsParameterizedTest;
 import org.springframework.web.servlet.mvc.condition.ConsumesRequestCondition;
+import org.springframework.web.servlet.mvc.condition.MediaTypeExpression;
 import org.springframework.web.servlet.mvc.method.RequestMappingInfo;
 import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
 import org.springframework.web.util.ServletRequestPathUtils;
+import org.springframework.web.util.pattern.PathPattern;
 import org.springframework.web.util.pattern.PathPatternParser;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -62,6 +65,7 @@ import static org.mockito.Mockito.mock;
  *
  * @author Rossen Stoyanchev
  * @author Sam Brannen
+ * @author Olga Maciaszek-Sharma
  */
 public class RequestMappingHandlerMappingTests {
 
@@ -278,6 +282,53 @@ public class RequestMappingHandlerMappingTests {
 		assertComposedAnnotationMapping(RequestMethod.PATCH);
 	}
 
+	@SuppressWarnings("DataFlowIssue")
+	@Test
+	void httpExchangeWithDefaultValues() throws NoSuchMethodException {
+		RequestMappingHandlerMapping mapping = new RequestMappingHandlerMapping();
+		mapping.setApplicationContext(new StaticWebApplicationContext());
+		mapping.afterPropertiesSet();
+
+		RequestMappingInfo mappingInfo = mapping.getMappingForMethod(
+				HttpExchangeController.class.getMethod("defaultValuesExchange"),
+				HttpExchangeController.class);
+
+		assertThat(mappingInfo.getPathPatternsCondition().getPatterns())
+				.extracting(PathPattern::toString)
+				.containsOnly("/exchange");
+		assertThat(mappingInfo.getMethodsCondition().getMethods()).isEmpty();
+		assertThat(mappingInfo.getParamsCondition().getExpressions()).isEmpty();
+		assertThat(mappingInfo.getHeadersCondition().getExpressions()).isEmpty();
+		assertThat(mappingInfo.getConsumesCondition().getExpressions()).isEmpty();
+		assertThat(mappingInfo.getProducesCondition().getExpressions()).isEmpty();
+	}
+
+	@SuppressWarnings("DataFlowIssue")
+	@Test
+	void httpExchangeWithCustomValues() throws NoSuchMethodException {
+		RequestMappingHandlerMapping mapping = new RequestMappingHandlerMapping();
+		mapping.setApplicationContext(new StaticWebApplicationContext());
+		mapping.afterPropertiesSet();
+
+		RequestMappingInfo mappingInfo = mapping.getMappingForMethod(
+				HttpExchangeController.class.getMethod("customValuesExchange"),
+				HttpExchangeController.class);
+
+		assertThat(mappingInfo.getPathPatternsCondition().getPatterns())
+				.extracting(PathPattern::toString)
+				.containsOnly("/exchange/custom");
+		assertThat(mappingInfo.getMethodsCondition().getMethods())
+				.containsOnly(RequestMethod.POST);
+		assertThat(mappingInfo.getParamsCondition().getExpressions()).isEmpty();
+		assertThat(mappingInfo.getHeadersCondition().getExpressions()).isEmpty();
+		assertThat(mappingInfo.getConsumesCondition().getExpressions())
+				.extracting(MediaTypeExpression::getMediaType)
+				.containsOnly(MediaType.APPLICATION_JSON);
+		assertThat(mappingInfo.getProducesCondition().getExpressions())
+				.extracting(MediaTypeExpression::getMediaType)
+				.containsOnly(MediaType.valueOf("text/plain;charset=UTF-8"));
+	}
+
 	private RequestMappingInfo assertComposedAnnotationMapping(RequestMethod requestMethod) throws Exception {
 
 		RequestMappingHandlerMapping mapping = new RequestMappingHandlerMapping();
@@ -367,6 +418,18 @@ public class RequestMappingHandlerMappingTests {
 		}
 	}
 
+	@RestController
+	@HttpExchange("/exchange")
+	static class HttpExchangeController {
+
+		@HttpExchange
+		public void defaultValuesExchange(){}
+
+		@HttpExchange(value = "/custom", accept = "text/plain;charset=UTF-8",
+				method = "POST", contentType =  "application/json")
+		public void customValuesExchange(){}
+	}
+
 
 	private static class Foo {
 	}