Optimize object creation PartialMatchHelper

Closes gh-29667

Author: rstoyanchev

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/RequestMappingInfoHandlerMapping.java

@@ -36,6 +36,7 @@
 import org.springframework.http.server.PathContainer;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.method.HandlerMethod;
@@ -165,8 +166,11 @@ protected void handleMatch(RequestMappingInfo info, HandlerMethod handlerMethod,
 	protected HandlerMethod handleNoMatch(Set<RequestMappingInfo> infos,
 			ServerWebExchange exchange) throws Exception {
 
-		PartialMatchHelper helper = new PartialMatchHelper(infos, exchange);
+		if (CollectionUtils.isEmpty(infos)) {
+			return null;
+		}
 
+		PartialMatchHelper helper = new PartialMatchHelper(infos, exchange);
 		if (helper.isEmpty()) {
 			return null;
 		}
@@ -218,15 +222,14 @@ private static class PartialMatchHelper {
 
 		private final List<PartialMatch> partialMatches = new ArrayList<>();
 
-
-		public PartialMatchHelper(Set<RequestMappingInfo> infos, ServerWebExchange exchange) {
-			this.partialMatches.addAll(infos.stream().
-					filter(info -> info.getPatternsCondition().getMatchingCondition(exchange) != null).
-					map(info -> new PartialMatch(info, exchange)).
-					collect(Collectors.toList()));
+		PartialMatchHelper(Set<RequestMappingInfo> infos, ServerWebExchange exchange) {
+			for (RequestMappingInfo info : infos) {
+				if (info.getPatternsCondition().getMatchingCondition(exchange) != null) {
+					this.partialMatches.add(new PartialMatch(info, exchange));
+				}
+			}
 		}
 
-
 		/**
 		 * Whether there are any partial matches.
 		 */

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * 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.
@@ -22,6 +22,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.EnumSet;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -334,9 +335,18 @@ public void handlePatchUnsupportedMediaType() {
 					assertThat(umtse.getResponseHeaders().getAcceptPatch()).containsExactly(mediaType);
 				})
 				.verify();
-
 	}
 
+	@Test // gh-29611
+	public void handleNoMatchWithoutPartialMatches() throws Exception {
+		ServerWebExchange exchange = MockServerWebExchange.from(post("/non-existent"));
+
+		HandlerMethod handlerMethod = this.handlerMapping.handleNoMatch(new HashSet<>(), exchange);
+		assertThat(handlerMethod).isNull();
+
+		handlerMethod = this.handlerMapping.handleNoMatch(null, exchange);
+		assertThat(handlerMethod).isNull();
+	}
 
 	@SuppressWarnings("unchecked")
 	private <T> void assertError(Mono<Object> mono, final Class<T> exceptionClass, final Consumer<T> consumer) {

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

@@ -241,6 +241,10 @@ private Map<String, MultiValueMap<String, String>> extractMatrixVariables(
 	protected HandlerMethod handleNoMatch(
 			Set<RequestMappingInfo> infos, String lookupPath, HttpServletRequest request) throws ServletException {
 
+		if (CollectionUtils.isEmpty(infos)) {
+			return null;
+		}
+
 		PartialMatchHelper helper = new PartialMatchHelper(infos, request);
 		if (helper.isEmpty()) {
 			return null;
@@ -291,7 +295,7 @@ private static class PartialMatchHelper {
 
 		private final List<PartialMatch> partialMatches = new ArrayList<>();
 
-		public PartialMatchHelper(Set<RequestMappingInfo> infos, HttpServletRequest request) {
+		PartialMatchHelper(Set<RequestMappingInfo> infos, HttpServletRequest request) {
 			for (RequestMappingInfo info : infos) {
 				if (info.getActivePatternsCondition().getMatchingCondition(request) != null) {
 					this.partialMatches.add(new PartialMatch(info, request));

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * 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.
@@ -389,6 +389,18 @@ void handleMatchMatrixVariablesDecoding(TestRequestMappingInfoHandlerMapping map
 		assertThat(uriVariables.get("cars")).isEqualTo("cars");
 	}
 
+	@PathPatternsParameterizedTest // gh-29611
+	void handleNoMatchWithoutPartialMatches(TestRequestMappingInfoHandlerMapping mapping) throws Exception {
+		String path = "/non-existent";
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", path);
+
+		HandlerMethod handlerMethod = mapping.handleNoMatch(new HashSet<>(), path, request);
+		assertThat(handlerMethod).isNull();
+
+		handlerMethod = mapping.handleNoMatch(null, path, request);
+		assertThat(handlerMethod).isNull();
+	}
+
 	private HandlerMethod getHandler(
 			TestRequestMappingInfoHandlerMapping mapping, MockHttpServletRequest request) throws Exception {