Support non-standard HTTP methods in FrameworkServlet

This commit ensures that HTTP methods not supported by HttpServlet, for
instance WebDAV methods, are still supported in FrameworkServlet.

Closes gh-29689

Author: poutsma

spring-webmvc/src/main/java/org/springframework/web/servlet/FrameworkServlet.java

@@ -21,6 +21,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.Callable;
 import java.util.stream.Collectors;
 
@@ -167,6 +168,12 @@ public abstract class FrameworkServlet extends HttpServletBean implements Applic
 	 */
 	private static final String INIT_PARAM_DELIMITERS = ",; \t\n";
 
+	/**
+	 * HTTP methods supported by {@link jakarta.servlet.http.HttpServlet}.
+	 */
+	private static final Set<String> HTTP_SERVLET_METHODS = Set.of("DELETE", "HEAD", "GET", "OPTIONS", "POST", "PUT",
+			"TRACE");
+
 
 	/** ServletContext attribute to find the WebApplicationContext in. */
 	@Nullable
@@ -866,18 +873,18 @@ public void destroy() {
 
 
 	/**
-	 * Override the parent class implementation in order to intercept PATCH requests.
+	 * Override the parent class implementation in order to intercept requests
+	 * using PATCH or non-standard HTTP methods (WebDAV).
 	 */
 	@Override
 	protected void service(HttpServletRequest request, HttpServletResponse response)
 			throws ServletException, IOException {
 
-		HttpMethod httpMethod = HttpMethod.valueOf(request.getMethod());
-		if (HttpMethod.PATCH.equals(httpMethod)) {
-			processRequest(request, response);
+		if (HTTP_SERVLET_METHODS.contains(request.getMethod())) {
+			super.service(request, response);
 		}
 		else {
-			super.service(request, response);
+			processRequest(request, response);
 		}
 	}
 

spring-webmvc/src/test/java/org/springframework/web/servlet/DispatcherServletTests.java

@@ -875,6 +875,14 @@ public void mixedInitializerClasses() throws Exception {
 		assertThat(getServletContext().getAttribute("otherInitialized")).isEqualTo("true");
 	}
 
+	@Test
+	public void webDavMethod() throws Exception {
+		MockHttpServletRequest request = new MockHttpServletRequest(getServletContext(), "PROPFIND", "/body.do");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		complexDispatcherServlet.service(request, response);
+		assertThat(response.getContentAsString()).isEqualTo("body");
+	}
+
 
 	public static class ControllerFromParent implements Controller {