From 5ca79281535fc62f5c2ffc7b432e5322b6e7366e Mon Sep 17 00:00:00 2001
From: Rossen Stoyanchev <rstoyanchev@pivotal.io>
Date: Tue, 19 May 2020 10:30:07 +0100
Subject: [PATCH] Use Servlet 4 mapping type if available

See gh-25100
---
 spring-web/spring-web.gradle                  |  2 +-
 .../web/util/UrlPathHelper.java               | 57 +++++++++++++------
 2 files changed, 41 insertions(+), 18 deletions(-)

diff --git a/spring-web/spring-web.gradle b/spring-web/spring-web.gradle
index 0ddcc57f9a1c..48599d427a80 100644
--- a/spring-web/spring-web.gradle
+++ b/spring-web/spring-web.gradle
@@ -8,7 +8,7 @@ dependencies {
 	optional(project(":spring-aop"))
 	optional(project(":spring-context"))
 	optional(project(":spring-oxm"))
-	optional("javax.servlet:javax.servlet-api:3.1.0")
+	optional("javax.servlet:javax.servlet-api") // Servlet 4 for mapping type
 	optional("javax.servlet.jsp:javax.servlet.jsp-api")
 	optional("javax.el:javax.el-api")
 	optional("javax.faces:javax.faces-api")
diff --git a/spring-web/src/main/java/org/springframework/web/util/UrlPathHelper.java b/spring-web/src/main/java/org/springframework/web/util/UrlPathHelper.java
index 5e3ed3b52eec..a3ba76492dd2 100644
--- a/spring-web/src/main/java/org/springframework/web/util/UrlPathHelper.java
+++ b/spring-web/src/main/java/org/springframework/web/util/UrlPathHelper.java
@@ -23,11 +23,13 @@
 import java.util.Properties;
 
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.MappingMatch;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.lang.Nullable;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
@@ -49,6 +51,10 @@
  */
 public class UrlPathHelper {
 
+	private static boolean isServlet4Present =
+			ClassUtils.isPresent("javax.servlet.http.HttpServletMapping",
+					UrlPathHelper.class.getClassLoader());
+
 	/**
 	 * Special WebSphere request attribute, indicating the original request URI.
 	 * Preferable over the standard Servlet 2.4 forward attribute on WebSphere,
@@ -154,6 +160,26 @@ protected String getDefaultEncoding() {
 	}
 
 
+	/**
+	 * Variant of {@link #getLookupPathForRequest(HttpServletRequest)} that
+	 * automates checking for a previously computed lookupPath saved as a
+	 * request attribute. The attribute is only used for lookup purposes.
+	 * @param request current HTTP request
+	 * @param lookupPathAttributeName the request attribute to check
+	 * @return the lookup path
+	 * @since 5.2
+	 * @see org.springframework.web.servlet.HandlerMapping#LOOKUP_PATH
+	 */
+	public String getLookupPathForRequest(HttpServletRequest request, @Nullable String lookupPathAttributeName) {
+		if (lookupPathAttributeName != null) {
+			String result = (String) request.getAttribute(lookupPathAttributeName);
+			if (result != null) {
+				return result;
+			}
+		}
+		return getLookupPathForRequest(request);
+	}
+
 	/**
 	 * Return the mapping lookup path for the given request, within the current
 	 * servlet mapping if applicable, else within the web application.
@@ -165,7 +191,7 @@ protected String getDefaultEncoding() {
 	 */
 	public String getLookupPathForRequest(HttpServletRequest request) {
 		// Always use full path within current servlet context?
-		if (this.alwaysUseFullPath) {
+		if (this.alwaysUseFullPath || skipServletPathDetermination(request)) {
 			return getPathWithinApplication(request);
 		}
 		// Else, use path within current servlet mapping if applicable
@@ -178,24 +204,14 @@ public String getLookupPathForRequest(HttpServletRequest request) {
 		}
 	}
 
-	/**
-	 * Variant of {@link #getLookupPathForRequest(HttpServletRequest)} that
-	 * automates checking for a previously computed lookupPath saved as a
-	 * request attribute. The attribute is only used for lookup purposes.
-	 * @param request current HTTP request
-	 * @param lookupPathAttributeName the request attribute to check
-	 * @return the lookup path
-	 * @since 5.2
-	 * @see org.springframework.web.servlet.HandlerMapping#LOOKUP_PATH
-	 */
-	public String getLookupPathForRequest(HttpServletRequest request, @Nullable String lookupPathAttributeName) {
-		if (lookupPathAttributeName != null) {
-			String result = (String) request.getAttribute(lookupPathAttributeName);
-			if (result != null) {
-				return result;
+	private boolean skipServletPathDetermination(HttpServletRequest request) {
+		if (isServlet4Present) {
+			if (request.getHttpServletMapping().getMappingMatch() != null) {
+				return !request.getHttpServletMapping().getMappingMatch().equals(MappingMatch.PATH) ||
+						request.getHttpServletMapping().getPattern().equals("/*");
 			}
 		}
-		return getLookupPathForRequest(request);
+		return false;
 	}
 
 	/**
@@ -658,4 +674,11 @@ public void setDefaultEncoding(String defaultEncoding) {
 			throw new UnsupportedOperationException();
 		}
 	};
+
+
+	private static class HttpServletMappingHelper {
+
+
+
+	}
 }