app null valid

src/main/java/com/reyun/controller/EventController.java

@@ -17,6 +17,7 @@ import org.springframework.web.bind.annotation.*;
 
 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -100,6 +101,9 @@ public class EventController {
     @RequestMapping(value = "find4tracking", method = RequestMethod.GET)
     public ResultModel findAllEvent4Tracking(@PathVariable Long app, @RequestParam String appkey) {
         App appObject = appRepository.findByAppkey(appkey);
+        if (appObject == null) {
+            return ResultModel.OK(new ArrayList());
+        }
         return ResultModel.OK(eventService.listEvent4Tracking(appObject.getId()));
     }