Allow Resource to add headers for range requests

Closes gh-25976

Author: rstoyanchev

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceWebHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -352,15 +352,14 @@ public Mono<Void> handle(ServerWebExchange exchange) {
 
 						// Check the media type for the resource
 						MediaType mediaType = MediaTypeFactory.getMediaType(resource).orElse(null);
+						setHeaders(exchange, resource, mediaType);
 
 						// Content phase
 						if (HttpMethod.HEAD.matches(exchange.getRequest().getMethodValue())) {
-							setHeaders(exchange, resource, mediaType);
 							exchange.getResponse().getHeaders().set(HttpHeaders.ACCEPT_RANGES, "bytes");
 							return Mono.empty();
 						}
 
-						setHeaders(exchange, resource, mediaType);
 						ResourceHttpMessageWriter writer = getResourceHttpMessageWriter();
 						Assert.state(writer != null, "No ResourceHttpMessageWriter");
 						return writer.write(Mono.just(resource),
@@ -535,6 +534,7 @@ protected void setHeaders(ServerWebExchange exchange, Resource resource, @Nullab
 		if (mediaType != null) {
 			headers.setContentType(mediaType);
 		}
+
 		if (resource instanceof HttpResource) {
 			HttpHeaders resourceHeaders = ((HttpResource) resource).getResponseHeaders();
 			exchange.getResponse().getHeaders().putAll(resourceHeaders);

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

@@ -475,22 +475,20 @@ public void handleRequest(HttpServletRequest request, HttpServletResponse respon
 
 		// Check the media type for the resource
 		MediaType mediaType = getMediaType(request, resource);
+		setHeaders(response, resource, mediaType);
 
 		// Content phase
 		if (METHOD_HEAD.equals(request.getMethod())) {
-			setHeaders(response, resource, mediaType);
 			return;
 		}
 
 		ServletServerHttpResponse outputMessage = new ServletServerHttpResponse(response);
 		if (request.getHeader(HttpHeaders.RANGE) == null) {
 			Assert.state(this.resourceHttpMessageConverter != null, "Not initialized");
-			setHeaders(response, resource, mediaType);
 			this.resourceHttpMessageConverter.write(resource, mediaType, outputMessage);
 		}
 		else {
 			Assert.state(this.resourceRegionHttpMessageConverter != null, "Not initialized");
-			response.setHeader(HttpHeaders.ACCEPT_RANGES, "bytes");
 			ServletServerHttpRequest inputMessage = new ServletServerHttpRequest(request);
 			try {
 				List<HttpRange> httpRanges = inputMessage.getHeaders().getRange();
@@ -499,7 +497,7 @@ public void handleRequest(HttpServletRequest request, HttpServletResponse respon
 						HttpRange.toResourceRegions(httpRanges, resource), mediaType, outputMessage);
 			}
 			catch (IllegalArgumentException ex) {
-				response.setHeader("Content-Range", "bytes */" + resource.contentLength());
+				response.setHeader(HttpHeaders.CONTENT_RANGE, "bytes */" + resource.contentLength());
 				response.sendError(HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE);
 			}
 		}
@@ -694,6 +692,7 @@ protected void setHeaders(HttpServletResponse response, Resource resource, @Null
 		if (mediaType != null) {
 			response.setContentType(mediaType.toString());
 		}
+
 		if (resource instanceof HttpResource) {
 			HttpHeaders resourceHeaders = ((HttpResource) resource).getResponseHeaders();
 			resourceHeaders.forEach((headerName, headerValues) -> {
@@ -709,6 +708,7 @@ protected void setHeaders(HttpServletResponse response, Resource resource, @Null
 				}
 			});
 		}
+
 		response.setHeader(HttpHeaders.ACCEPT_RANGES, "bytes");
 	}
 

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

@@ -24,6 +24,7 @@
 
 import javax.servlet.http.HttpServletResponse;
 
+import org.hamcrest.CoreMatchers;
 import org.hamcrest.Matchers;
 import org.junit.Before;
 import org.junit.Test;
@@ -650,6 +651,35 @@ public void partialContentMultipleByteRanges() throws Exception {
 		assertEquals("t.", ranges[11]);
 	}
 
+	@Test // gh-25976
+	public void partialContentByteRangeWithEncodedResource() throws Exception {
+		String path = "js/foo.js";
+		EncodedResourceResolverTests.createGzippedFile(path);
+
+		ResourceHttpRequestHandler handler = new ResourceHttpRequestHandler();
+		handler.setResourceResolvers(Arrays.asList(new EncodedResourceResolver(), new PathResourceResolver()));
+		handler.setLocations(Collections.singletonList(new ClassPathResource("test/", getClass())));
+		handler.setServletContext(new MockServletContext());
+		handler.afterPropertiesSet();
+
+		this.request.addHeader("Accept-Encoding", "gzip");
+		this.request.addHeader("Range", "bytes=0-1");
+		this.request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, path);
+		handler.handleRequest(this.request, this.response);
+
+		assertEquals(206, this.response.getStatus());
+		assertThat(response.getHeaderNames(), CoreMatchers.hasItems(
+				"Last-Modified",  "Content-Length", "Content-Type", "Content-Encoding",
+				"Vary", "Accept-Ranges", "Content-Range"));
+
+		assertEquals("application/javascript", this.response.getContentType());
+		assertEquals(2, this.response.getContentLength());
+		assertEquals("bytes 0-1/66", this.response.getHeader("Content-Range"));
+		assertEquals("bytes", this.response.getHeaderValue("Accept-Ranges"));
+		assertEquals("gzip", this.response.getHeaderValue("Content-Encoding"));
+		assertEquals("Accept-Encoding", this.response.getHeaderValue("Vary"));
+	}
+
 	@Test  // SPR-14005
 	public void doOverwriteExistingCacheControlHeaders() throws Exception {
 		this.request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, "foo.css");