Resolve bug which returns invalid background image occasionally

Author: boyter

src/main/java/com/searchcode/app/service/route/CodeRouteService.java

@@ -129,7 +129,7 @@ public ModelAndView root(Request request, Response response) {
             return new ModelAndView(map, "search_ajax.ftl");
         }
 
-        map.put("photoId", CommonRouteService.getPhotoId());
+        map.put("photoId", CommonRouteService.getPhotoId(Calendar.getInstance().get(Calendar.DAY_OF_YEAR)));
         if (request.queryParams().contains("photoId")) {
             map.put("photoId", request.queryParams("photoId"));
         }
@@ -445,7 +445,7 @@ public ModelAndView html(Request request, Response response) {
             return new ModelAndView(map, "searchresults.ftl");
         }
 
-        map.put("photoId", CommonRouteService.getPhotoId());
+        map.put("photoId", CommonRouteService.getPhotoId(Calendar.getInstance().get(Calendar.DAY_OF_YEAR)));
         map.put("numDocs", this.indexService.getCodeIndexLinesCount());
         map.put("logoImage", CommonRouteService.getLogo());
         map.put("isCommunity", App.ISCOMMUNITY);

src/main/java/com/searchcode/app/service/route/CommonRouteService.java

@@ -151,8 +151,8 @@ public static String getSyntaxHighlighter() {
         return highlighter;
     }
 
-    public static int getPhotoId() {
-        Random random = new Random(Calendar.getInstance().get(Calendar.DAY_OF_YEAR));
-        return random.nextInt((42 - 1) + 1);
+    public static int getPhotoId(int seed) {
+        Random random = new Random();
+        return random.nextInt(42) + 1;
     }
 }

src/test/java/com/searchcode/app/service/route/CommonRouteServiceTest.java

@@ -0,0 +1,21 @@
+package com.searchcode.app.service.route;
+
+import junit.framework.TestCase;
+
+import java.util.Calendar;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+
+public class CommonRouteServiceTest extends TestCase {
+    public void testGetPhotoId() {
+
+        int photoId =  CommonRouteService.getPhotoId(Calendar.getInstance().get(Calendar.DAY_OF_YEAR));
+        assertThat(photoId).isBetween(1, 42);
+
+        for (int i = 0; i < 10000; i++) {
+            photoId = CommonRouteService.getPhotoId(i);
+            assertThat(photoId).isBetween(1, 42);
+        }
+    }
+}