Explicit HEAD sorted higher than implicit one

Same fix as #7cdcc1 but for WebFlux.

Issue: SPR-14182

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/RequestMethodsRequestCondition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -39,8 +39,8 @@ import org.springframework.web.server.ServerWebExchange;
  */
 public final class RequestMethodsRequestCondition extends AbstractRequestCondition<RequestMethodsRequestCondition> {
 
-	private static final RequestMethodsRequestCondition HEAD_CONDITION =
-			new RequestMethodsRequestCondition(RequestMethod.HEAD);
+	private static final RequestMethodsRequestCondition GET_CONDITION =
+			new RequestMethodsRequestCondition(RequestMethod.GET);
 
 
 	private final Set<RequestMethod> methods;
@@ -139,7 +139,7 @@ public final class RequestMethodsRequestCondition extends AbstractRequestConditi
 				}
 			}
 			if (httpMethod == HttpMethod.HEAD && getMethods().contains(RequestMethod.GET)) {
-				return HEAD_CONDITION;
+				return GET_CONDITION;
 			}
 		}
 		return null;
@@ -158,7 +158,18 @@ public final class RequestMethodsRequestCondition extends AbstractRequestConditi
 	 */
 	@Override
 	public int compareTo(RequestMethodsRequestCondition other, ServerWebExchange exchange) {
-		return (other.methods.size() - this.methods.size());
+		if (other.methods.size() != this.methods.size()) {
+			return other.methods.size() - this.methods.size();
+		}
+		else if (this.methods.size() == 1) {
+			if (this.methods.contains(RequestMethod.HEAD) && other.methods.contains(RequestMethod.GET)) {
+				return -1;
+			}
+			else if (this.methods.contains(RequestMethod.GET) && other.methods.contains(RequestMethod.HEAD)) {
+				return 1;
+			}
+		}
+		return 0;
 	}
 
 }

spring-webflux/src/test/java/org/springframework/web/reactive/result/condition/RequestMethodsRequestConditionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -51,7 +51,7 @@ public class RequestMethodsRequestConditionTests {
 	@Test
 	public void getMatchingConditionWithHttpHead() throws Exception {
 		testMatch(new RequestMethodsRequestCondition(HEAD), HEAD);
-		testMatch(new RequestMethodsRequestCondition(GET), HEAD);
+		testMatch(new RequestMethodsRequestCondition(GET), GET);
 		testNoMatch(new RequestMethodsRequestCondition(POST), HEAD);
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -31,6 +31,8 @@ import org.springframework.http.RequestEntity;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.reactive.config.EnableWebFlux;
 import org.springframework.web.server.adapter.ForwardedHeaderTransformer;
@@ -100,10 +102,16 @@ public class RequestMappingIntegrationTests extends AbstractRequestMappingIntegr
 	private static class TestRestController {
 
 		@GetMapping("/text")
-		public String text() {
+		public String textGet() {
 			return "Foo";
 		}
 
+		// SPR-17593: explicit HEAD should not clash with implicit mapping via GET
+		@RequestMapping(path = "/text", method = RequestMethod.HEAD)
+		public String textHead() {
+			return textGet();
+		}
+
 		@GetMapping("/uri")
 		public String uri(ServerHttpRequest request) {
 			return request.getURI().toString();