Allow adding registration directly in ResourceHandlerRegistry

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/ResourceHandlerRegistration.java

@@ -223,11 +223,19 @@ protected String[] getPathPatterns() {
 		return this.pathPatterns;
 	}
 
+	/**
+	 * Create the resource handler.
+	 * Return a {@link ResourceHttpRequestHandler} instance.
+	 */
+	protected ResourceHttpRequestHandler createRequestHandler() {
+		return new ResourceHttpRequestHandler();
+	}
+
 	/**
 	 * Return a {@link ResourceHttpRequestHandler} instance.
 	 */
 	protected ResourceHttpRequestHandler getRequestHandler() {
-		ResourceHttpRequestHandler handler = new ResourceHttpRequestHandler();
+		ResourceHttpRequestHandler handler = createRequestHandler();
 		if (this.resourceChainRegistration != null) {
 			handler.setResourceResolvers(this.resourceChainRegistration.getResourceResolvers());
 			handler.setResourceTransformers(this.resourceChainRegistration.getResourceTransformers());

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/ResourceHandlerRegistry.java

@@ -130,6 +130,22 @@ public ResourceHandlerRegistration addResourceHandler(String... pathPatterns) {
 		return registration;
 	}
 
+	/**
+	 * Add a resource handler to serve static resources. The handler is invoked
+	 * for requests that match one of the specified URL path patterns.
+	 * <p>Patterns such as {@code "/static/**"} or {@code "/css/{filename:\\w+\\.css}"}
+	 * are supported. This method allows users to register a subclass of {@link ResourceHandlerRegistration}.
+	 * <p>For pattern syntax see {@link PathPattern} when parsed patterns
+	 * are {@link PathMatchConfigurer#setPatternParser enabled} or
+	 * {@link AntPathMatcher} otherwise. The syntax is largely the same with
+	 * {@link PathPattern} more tailored for web usage and more efficient.
+	 */
+	public ResourceHandlerRegistration addResourceHandler(ResourceHandlerRegistration registration) {
+		Assert.notNull(registration, "ResourceHandlerRegistration must not be null");
+		this.registrations.add(registration);
+		return registration;
+	}
+
 	/**
 	 * Whether a resource handler has already been registered for the given path pattern.
 	 */

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/ResourceHandlerRegistryTests.java

@@ -19,11 +19,16 @@
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
+import jakarta.servlet.http.HttpServletRequest;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.cache.concurrent.ConcurrentMapCache;
+import org.springframework.core.io.Resource;
 import org.springframework.http.CacheControl;
+import org.springframework.http.MediaType;
+import org.springframework.util.StringUtils;
 import org.springframework.web.accept.ContentNegotiationManager;
 import org.springframework.web.context.support.GenericWebApplicationContext;
 import org.springframework.web.servlet.HandlerMapping;
@@ -71,6 +76,8 @@ void setup() {
 
 		this.registration = this.registry.addResourceHandler("/resources/**");
 		this.registration.addResourceLocations("classpath:org/springframework/web/servlet/config/annotation/");
+		this.registry.addResourceHandler(new NoExtensionAsHtmlResourceHttpHandlerRegistration("/noext/**"))
+				.addResourceLocations("classpath:org/springframework/web/servlet/config/annotation/noext/");
 		this.response = new MockHttpServletResponse();
 	}
 
@@ -224,4 +231,45 @@ void lastModifiedDisabled() {
 		assertThat(handler.isUseLastModified()).isFalse();
 	}
 
+	@Test
+	void noExtensionResource() throws Exception {
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("GET");
+		request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, "/noExtResource");
+
+		ResourceHttpRequestHandler handler = getHandler("/noext/**");
+		handler.handleRequest(request, this.response);
+
+		assertThat(this.response.getContentType()).isEqualTo("text/html");
+	}
+
+
+	static class NoExtensionAsHtmlResourceHttpHandlerRegistration extends ResourceHandlerRegistration {
+
+		public NoExtensionAsHtmlResourceHttpHandlerRegistration(String... pathPatterns) {
+			super(pathPatterns);
+		}
+
+		@Override
+		protected ResourceHttpRequestHandler createRequestHandler() {
+			return new NoExtensionAsHtmlResourceHttpHandler();
+		}
+	}
+
+	static class NoExtensionAsHtmlResourceHttpHandler extends ResourceHttpRequestHandler {
+
+		@Override
+		protected @Nullable MediaType getMediaType(HttpServletRequest request, Resource resource) {
+			String filename = resource.getFilename();
+			String ext = StringUtils.getFilenameExtension(filename);
+			if (!StringUtils.hasText(ext)) {
+				return MediaType.TEXT_HTML;
+			}
+			else {
+				return super.getMediaType(request, resource);
+			}
+		}
+	}
+
+
 }

spring-webmvc/src/test/resources/org/springframework/web/servlet/config/annotation/noext/noExtResource

@@ -0,0 +1 @@
+no ext