SPR-7706 - 304 responses should not have non-0 Content-Length

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/resource/ResourceHttpRequestHandler.java

@@ -5,7 +5,7 @@
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -121,11 +121,11 @@ public class ResourceHttpRequestHandler extends WebContentGenerator implements H
 		}
 
 		// header phase
-		setHeaders(response, resource, mediaType);
 		if (new ServletWebRequest(request, response).checkNotModified(resource.lastModified())) {
 			logger.debug("Resource not modified - returning 304");
 			return;
 		}
+		setHeaders(response, resource, mediaType);
 
 		// content phase
 		if (METHOD_HEAD.equals(request.getMethod())) {