diff --git a/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java b/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java
index e0a00e8..0b601a6 100644
--- a/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java
+++ b/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java
@@ -28,13 +28,8 @@
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Integer getLayers(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid) {
-        var pages = gallery.getAnimationByAid(aid).getPages();
-        for (var p : pages) {
-            if (!p.getPid().equals(pid)) continue;
-            return p.getLayers().size();
-        }
-
-        throw new WebApplicationException(404);
+        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        return pages.get(pid).getLayers().size();
     }
 
 
@@ -47,9 +42,7 @@
     @POST
     @Produces(MediaType.APPLICATION_JSON)
     public Integer addLayer(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid) {
-        var layerSize = 4;
-        var pages = gallery.getAnimationByAid(aid).getPages();
-        var page = (Page) null;
+        var pages = gallery.getAnimationByAid(aid).getPageMap();
 
         for (var p : pages) {
             if (!p.getPid().equals(pid)) continue;
@@ -71,12 +64,8 @@
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Integer getStrokeNo(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid, @PathParam("layerNo") Integer layerNo) {
-        var pages = gallery.getAnimationByAid(aid).getPages();
-        var strokes = new ArrayList<Stroke>();
-        for (var p : pages) {
-            if (pid.equals(p.getPid()))
-                strokes = p.getLayers().get(layerNo).getStrokes();
-        }
+        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var strokes = pages.get(pid).getLayers().get(layerNo).getStrokes();
 
         if (strokes == null) return null;
         return (strokes.size() - 1);