Lectures: Use attachment name for file downloads (#9775)

src/main/java/de/tum/cit/aet/artemis/core/web/FileResource.java

@@ -219,7 +219,7 @@ public ResponseEntity<byte[]> getMarkdownFileForConversation(@PathVariable Long
     public ResponseEntity<byte[]> getMarkdownFile(@PathVariable String filename) {
         log.debug("REST request to get file : {}", filename);
         sanitizeFilenameElseThrow(filename);
-        return buildFileResponse(FilePathService.getMarkdownFilePath(), filename);
+        return buildFileResponse(FilePathService.getMarkdownFilePath(), filename, false);
     }
 
     /**
@@ -431,7 +431,7 @@ public ResponseEntity<byte[]> getLectureAttachment(@PathVariable Long lectureId,
         // check if the user is authorized to access the requested attachment unit
         checkAttachmentAuthorizationOrThrow(course, attachment);
 
-        return buildFileResponse(getActualPathFromPublicPathString(attachment.getLink()), false);
+        return buildFileResponse(getActualPathFromPublicPathString(attachment.getLink()), Optional.of(attachment.getName()));
     }
 
     /**
@@ -470,13 +470,13 @@ public ResponseEntity<byte[]> getLecturePdfAttachmentsMerged(@PathVariable Long
 
     /**
      * GET files/attachments/attachment-unit/:attachmentUnitId/:filename : Get the lecture unit attachment
+     * Accesses to this endpoint are created by the server itself in the FilePathService
      *
      * @param attachmentUnitId ID of the attachment unit, the attachment belongs to
      * @return The requested file, 403 if the logged-in user is not allowed to access it, or 404 if the file doesn't exist
      */
     @GetMapping("files/attachments/attachment-unit/{attachmentUnitId}/*")
     @EnforceAtLeastStudent
-    // TODO: this method is kind of redundant to the method getAttachmentFile below, double check if both are actually needed
     public ResponseEntity<byte[]> getAttachmentUnitAttachment(@PathVariable Long attachmentUnitId) {
         log.debug("REST request to get the file for attachment unit {} for students", attachmentUnitId);
         AttachmentUnit attachmentUnit = attachmentUnitRepository.findByIdElseThrow(attachmentUnitId);
@@ -487,8 +487,7 @@ public ResponseEntity<byte[]> getAttachmentUnitAttachment(@PathVariable Long att
 
         // check if the user is authorized to access the requested attachment unit
         checkAttachmentAuthorizationOrThrow(course, attachment);
-
-        return buildFileResponse(getActualPathFromPublicPathString(attachment.getLink()), false);
+        return buildFileResponse(getActualPathFromPublicPathString(attachment.getLink()), Optional.of(attachment.getName()));
     }
 
     /**
@@ -567,36 +566,49 @@ public ResponseEntity<byte[]> getAttachmentUnitAttachmentSlide(@PathVariable Lon
     }
 
     /**
-     * Builds the response with headers, body and content type for specified path and file name
+     * Builds the response with headers, body and content type for specified path containing the file name
      *
-     * @param path     to the file
-     * @param filename the name of the file
+     * @param path  to the file including the file name
+     * @param cache true if the response should contain a header that allows caching; false otherwise
      * @return response entity
      */
-    private ResponseEntity<byte[]> buildFileResponse(Path path, String filename) {
-        return buildFileResponse(path, filename, false);
+    private ResponseEntity<byte[]> buildFileResponse(Path path, boolean cache) {
+        return buildFileResponse(path.getParent(), path.getFileName().toString(), Optional.empty(), cache);
     }
 
     /**
      * Builds the response with headers, body and content type for specified path containing the file name
      *
-     * @param path  to the file including the file name
-     * @param cache true if the response should contain a header that allows caching; false otherwise
+     * @param path     to the file including the file name
+     * @param filename the name of the file
+     * @param cache    true if the response should contain a header that allows caching; false otherwise
      * @return response entity
      */
-    private ResponseEntity<byte[]> buildFileResponse(Path path, boolean cache) {
-        return buildFileResponse(path.getParent(), path.getFileName().toString(), cache);
+    private ResponseEntity<byte[]> buildFileResponse(Path path, String filename, boolean cache) {
+        return buildFileResponse(path, filename, Optional.empty(), cache);
     }
 
     /**
      * Builds the response with headers, body and content type for specified path and file name
      *
-     * @param path     to the file
-     * @param filename the name of the file
-     * @param cache    true if the response should contain a header that allows caching; false otherwise
+     * @param path            to the file
+     * @param replaceFilename replaces the downloaded file's name, if provided
      * @return response entity
      */
-    private ResponseEntity<byte[]> buildFileResponse(Path path, String filename, boolean cache) {
+    private ResponseEntity<byte[]> buildFileResponse(Path path, Optional<String> replaceFilename) {
+        return buildFileResponse(path.getParent(), path.getFileName().toString(), replaceFilename, false);
+    }
+
+    /**
+     * Builds the response with headers, body and content type for specified path and file name
+     *
+     * @param path            to the file
+     * @param filename        the name of the file
+     * @param replaceFilename replaces the downloaded file's name, if provided
+     * @param cache           true if the response should contain a header that allows caching; false otherwise
+     * @return response entity
+     */
+    private ResponseEntity<byte[]> buildFileResponse(Path path, String filename, Optional<String> replaceFilename, boolean cache) {
         try {
             Path actualPath = path.resolve(filename);
             byte[] file = fileService.getFileForPath(actualPath);
@@ -611,7 +623,7 @@ private ResponseEntity<byte[]> buildFileResponse(Path path, String filename, boo
             String contentType = lowerCaseFilename.endsWith("htm") || lowerCaseFilename.endsWith("html") || lowerCaseFilename.endsWith("svg") || lowerCaseFilename.endsWith("svgz")
                     ? "attachment"
                     : "inline";
-            headers.setContentDisposition(ContentDisposition.builder(contentType).filename(filename).build());
+            headers.setContentDisposition(ContentDisposition.builder(contentType).filename(replaceFilename.orElse(filename)).build());
 
             var response = ResponseEntity.ok().headers(headers).contentType(getMediaTypeFromFilename(filename)).header("filename", filename);
             if (cache) {