speed up spring app

Demos/Spring/configuration.yml

@@ -58,7 +58,7 @@ annotation:
   # Pages preload
   # How many pages from a document should be loaded, remaining pages will be loaded on page scrolling
   # Set 0 to load all pages at once
-  preloadPageCount: 0
+  preloadPageCount: 1
   # Fonts path
   # Absolute path to custom fonts directory
   fontsDirectory:

Demos/Spring/src/main/java/com/groupdocs/ui/annotation/controller/AnnotationController.java

@@ -113,6 +113,38 @@ public PageDataDescriptionEntity loadDocumentPage(@RequestBody LoadDocumentPageR
         return annotationService.getDocumentPage(loadDocumentPageRequest);
     }
 
+    /**
+     * Get raw page image (PNG) - avoids Base64/JSON overhead for better performance
+     *
+     * @param documentGuid document path
+     * @param page page number (1-based)
+     * @param password document password (optional)
+     * @param response http response with PNG image
+     */
+    @RequestMapping(value = "/pageImage", method = RequestMethod.GET, produces = "image/png")
+    public void getPageImage(@RequestParam("guid") String documentGuid,
+                             @RequestParam("page") int page,
+                             @RequestParam(value = "password", required = false) String password,
+                             HttpServletResponse response) {
+        try {
+            byte[] imageBytes = annotationService.getPageImageBytes(documentGuid, page, password);
+
+            // Enable browser caching
+            response.setContentType("image/png");
+            response.setContentLength(imageBytes.length);
+            response.setHeader("Cache-Control", "private, max-age=300");
+
+            String etag = "\"" + documentGuid.hashCode() + "-" + page + "-" + new java.io.File(documentGuid).lastModified() + "\"";
+            response.setHeader("ETag", etag);
+
+            ServletOutputStream outputStream = response.getOutputStream();
+            outputStream.write(imageBytes);
+            outputStream.flush();
+        } catch (Exception ex) {
+            throw new TotalGroupDocsException(ex.getMessage(), ex);
+        }
+    }
+
     /**
      * Download document
      *

Demos/Spring/src/main/java/com/groupdocs/ui/annotation/service/AnnotationService.java

@@ -69,4 +69,14 @@ public interface AnnotationService {
      * @return stream of annotated document
      */
     InputStream annotateByStream(AnnotationPostedDataEntity annotateDocumentRequest);
+
+    /**
+     * Get raw page image bytes (PNG) for streaming endpoint
+     *
+     * @param guid document path
+     * @param pageNumber page number (1-based)
+     * @param password document password (nullable)
+     * @return PNG image bytes
+     */
+    byte[] getPageImageBytes(String guid, int pageNumber, String password);
 }