Optimize object creation in RequestMappingHandlerMapping#handleNoMatch

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.filter.reactive.ServerHttpObservationFilter;
@@ -169,7 +170,7 @@ protected void handleMatch(RequestMappingInfo info, HandlerMethod handlerMethod,
 	protected HandlerMethod handleNoMatch(Set<RequestMappingInfo> infos,
 			ServerWebExchange exchange) throws Exception {
 
-		PartialMatchHelper helper = new PartialMatchHelper(infos, exchange);
+		PartialMatchHelper helper = PartialMatchHelper.from(infos, exchange);
 
 		if (helper.isEmpty()) {
 			return null;
@@ -219,17 +220,27 @@ protected HandlerMethod handleNoMatch(Set<RequestMappingInfo> infos,
 	/**
 	 * Aggregate all partial matches and expose methods checking across them.
 	 */
-	private static class PartialMatchHelper {
+	private static final class PartialMatchHelper {
+
+		private static final PartialMatchHelper EMPTY_HELPER = new PartialMatchHelper(Collections.emptySet(), null);
 
 		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)).toList());
+		private PartialMatchHelper(Set<RequestMappingInfo> infos, ServerWebExchange exchange) {
+			for (RequestMappingInfo info : infos) {
+				if (info.getPatternsCondition().getMatchingCondition(exchange) != null) {
+					this.partialMatches.add(new PartialMatch(info, exchange));
+				}
+			}
 		}
 
+		public static PartialMatchHelper from(Set<RequestMappingInfo> infos, ServerWebExchange exchange) {
+			if (CollectionUtils.isEmpty(infos)) {
+				return EMPTY_HELPER;
+			}
+			return new PartialMatchHelper(infos, exchange);
+		}
 
 		/**
 		 * Whether there are any partial matches.

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

@@ -21,6 +21,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -345,6 +346,17 @@ public void handlePatchUnsupportedMediaType() {
 
 	}
 
+	@Test
+	public void handleNoMatchEmptyRequestMappingInfo() throws Exception {
+		ServerWebExchange exchange = MockServerWebExchange.from(post("/bar"));
+
+		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

@@ -246,7 +246,7 @@ private Map<String, MultiValueMap<String, String>> extractMatrixVariables(
 	protected HandlerMethod handleNoMatch(
 			Set<RequestMappingInfo> infos, String lookupPath, HttpServletRequest request) throws ServletException {
 
-		PartialMatchHelper helper = new PartialMatchHelper(infos, request);
+		PartialMatchHelper helper = PartialMatchHelper.from(infos, request);
 		if (helper.isEmpty()) {
 			return null;
 		}
@@ -293,18 +293,27 @@ protected HandlerMethod handleNoMatch(
 	/**
 	 * Aggregate all partial matches and expose methods checking across them.
 	 */
-	private static class PartialMatchHelper {
+	private static final class PartialMatchHelper {
+
+		private static final PartialMatchHelper EMPTY_HELPER = new PartialMatchHelper(Collections.emptySet(), null);
 
 		private final List<PartialMatch> partialMatches = new ArrayList<>();
 
-		public PartialMatchHelper(Set<RequestMappingInfo> infos, HttpServletRequest request) {
+		private PartialMatchHelper(Set<RequestMappingInfo> infos, HttpServletRequest request) {
 			for (RequestMappingInfo info : infos) {
 				if (info.getActivePatternsCondition().getMatchingCondition(request) != null) {
 					this.partialMatches.add(new PartialMatch(info, request));
 				}
 			}
 		}
 
+		public static PartialMatchHelper from(Set<RequestMappingInfo> infos, HttpServletRequest request) {
+			if (CollectionUtils.isEmpty(infos)) {
+				return EMPTY_HELPER;
+			}
+			return new PartialMatchHelper(infos, request);
+		}
+
 		/**
 		 * Whether there are any partial matches.
 		 */

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

@@ -25,6 +25,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -397,6 +398,17 @@ void handleMatchMatrixVariablesDecoding(TestRequestMappingInfoHandlerMapping map
 		assertThat(uriVariables.get("cars")).isEqualTo("cars");
 	}
 
+	@PathPatternsParameterizedTest
+	void handleNoMatchEmptyRequestMappingInfo(TestRequestMappingInfoHandlerMapping mapping) throws ServletException {
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/cars;color=green");
+
+		HandlerMethod handlerMethod = mapping.handleNoMatch(new HashSet<>(), "/{cars}", request);
+		assertThat(handlerMethod).isNull();
+
+		handlerMethod = mapping.handleNoMatch(null, "/{cars}", request);
+		assertThat(handlerMethod).isNull();
+	}
+
 	private HandlerMethod getHandler(
 			TestRequestMappingInfoHandlerMapping mapping, MockHttpServletRequest request) throws Exception {