Add Cache Filter for Parsed RequestPath

spring-web/src/main/java/org/springframework/web/util/ServletRequestPathUtils.java

@@ -16,11 +16,16 @@
 
 package org.springframework.web.util;
 
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
+import jakarta.servlet.Filter;
+import jakarta.servlet.FilterChain;
 import jakarta.servlet.RequestDispatcher;
+import jakarta.servlet.ServletException;
 import jakarta.servlet.ServletRequest;
+import jakarta.servlet.ServletResponse;
 import jakarta.servlet.http.HttpServletMapping;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.MappingMatch;
@@ -110,6 +115,14 @@ public static void clearParsedRequestPath(ServletRequest request) {
 		request.removeAttribute(PATH_ATTRIBUTE);
 	}
 
+	/**
+	 * Provide a {@link Filter} that manages the parsing and caching of a {@link RequestPath}.
+	 * @return the described {@link Filter}
+	 * @since 6.2.3
+	 */
+	public static Filter getParsedRequestPathCacheFilter() {
+		return new RequestPathCacheFilter();
+	}
 
 	// Methods to select either parsed RequestPath or resolved String lookupPath
 
@@ -312,4 +325,20 @@ PathElements withContextPath(String contextPath) {
 		}
 	}
 
+	private static final class RequestPathCacheFilter implements Filter {
+		public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
+			if (!(req instanceof HttpServletRequest request)) {
+				chain.doFilter(req, res);
+				return;
+			}
+			RequestPath previousRequestPath = (RequestPath) request.getAttribute(PATH_ATTRIBUTE);
+			try {
+				parseAndCache(request);
+				chain.doFilter(req, res);
+			}
+			finally {
+				setParsedRequestPath(previousRequestPath, request);
+			}
+		}
+	}
 }

spring-web/src/test/java/org/springframework/web/util/ServletRequestPathUtilsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -16,6 +16,12 @@
 
 package org.springframework.web.util;
 
+import java.io.IOException;
+
+import jakarta.servlet.Filter;
+import jakarta.servlet.RequestDispatcher;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletMapping;
 import jakarta.servlet.http.MappingMatch;
 import org.junit.jupiter.api.Test;
 
@@ -88,6 +94,35 @@ void modifyPathContextWithContextPathEndingWithSlash() {
 				.withMessage("Invalid contextPath '/persons/': must start with '/' and not end with '/'");
 	}
 
+	@Test
+	void filterParsesAndCachesThenCleansUp() throws IOException, ServletException {
+		MockHttpServletRequest request = createRequest("/servlet/request", "", "/servlet", "/request");
+		Filter filter = ServletRequestPathUtils.getParsedRequestPathCacheFilter();
+		filter.doFilter(request, null, (req, res) -> {
+			RequestPath currentPath = ServletRequestPathUtils.getParsedRequestPath(request);
+			assertThat(currentPath.pathWithinApplication().value()).isEqualTo("/request");
+		});
+		assertThat(ServletRequestPathUtils.hasParsedRequestPath(request)).isFalse();
+	}
+
+	@Test
+	void filterParsesCachesAndThenRestores() throws IOException, ServletException {
+		MockHttpServletRequest request = createRequest("/servlet/request", "", "/servlet", "/request");
+		RequestPath requestPath = ServletRequestPathUtils.parseAndCache(request);
+
+		HttpServletMapping mapping = new MockHttpServletMapping("/include", "", "myServlet", MappingMatch.PATH);
+		request.setAttribute(RequestDispatcher.INCLUDE_MAPPING, mapping);
+		request.setAttribute(WebUtils.INCLUDE_SERVLET_PATH_ATTRIBUTE, "/servlet");
+		request.setAttribute(WebUtils.INCLUDE_REQUEST_URI_ATTRIBUTE, "/servlet/include");
+
+		Filter filter = ServletRequestPathUtils.getParsedRequestPathCacheFilter();
+		filter.doFilter(request, null, (req, res) -> {
+			RequestPath currentPath = ServletRequestPathUtils.getParsedRequestPath(request);
+			assertThat(currentPath.pathWithinApplication().value()).isEqualTo("/include");
+		});
+		assertThat(requestPath).isEqualTo(ServletRequestPathUtils.getParsedRequestPath(request));
+	}
+
 	private void testParseAndCache(
 			String requestUri, String contextPath, String servletPath, String pathWithinApplication) {
 
@@ -100,13 +135,19 @@ private void testParseAndCache(
 	private static RequestPath createRequestPath(
 			String requestUri, String contextPath, String servletPath, String pathWithinApplication) {
 
+		MockHttpServletRequest request = createRequest(requestUri, contextPath, servletPath, pathWithinApplication);
+		return ServletRequestPathUtils.parseAndCache(request);
+	}
+
+	private static MockHttpServletRequest createRequest(
+			String requestUri, String contextPath, String servletPath, String pathWithinApplication) {
+
 		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
 		request.setContextPath(contextPath);
 		request.setServletPath(servletPath);
 		request.setHttpServletMapping(new MockHttpServletMapping(
 				pathWithinApplication, contextPath, "myServlet", MappingMatch.PATH));
-
-		return ServletRequestPathUtils.parseAndCache(request);
+		return request;
 	}
 
 }