added a isPresent() check and unregistered users are able start a cache now

src/main/java/hhn/labsw/bugageocaching/controller/Controller.java

@@ -40,27 +40,51 @@ public class Controller {
 
   @RequestMapping("/startCache")
   public @ResponseBody
-  Bearbeitet startCache(@RequestParam String userID,
+  String startCache(@RequestParam(value = "userID", defaultValue = "-1") String userID,
                     @RequestParam String cacheID,
                     @RequestParam String cacheAccesDefinitionID) {
 
+    if (!userID.equals("-1")) { // ein angemeldeter User startet den Cache
+
+      Bearbeitet bearbeitet = new Bearbeitet();
+
       Optional<User> userOptional = userRepository.findById(Integer.valueOf(userID));
+      if (userOptional.isPresent()) {
         User user = userOptional.get();
+        bearbeitet.setUser(user);
+      } else {
+        return "There is no user with the ID " + userID;
+      }
 
       Optional<Cache> cacheOptional = cacheRepository.findById(Integer.valueOf(cacheID));
+      if (cacheOptional.isPresent()) {
         Cache cache = cacheOptional.get();
+        bearbeitet.setCache(cache);
+      } else {
+        return "There is no cache with the ID " + cacheID;
+      }
 
       Optional<CacheAccesDefinition> cacheAccesDefinitionOptional =
           cacheAccesDefinitionRepository.findById(Integer.valueOf(cacheAccesDefinitionID));
+      if (cacheAccesDefinitionOptional.isPresent()) {
         CacheAccesDefinition cacheAccesDefinition = cacheAccesDefinitionOptional.get();
-
-    Bearbeitet bearbeitet = new Bearbeitet();
-    bearbeitet.setUser(user);
-    bearbeitet.setCache(cache);
         bearbeitet.setCacheAccesDefinition(cacheAccesDefinition);
+      } else {
+        return "There is no cacheAccesDefinition with the ID " + cacheAccesDefinitionID;
+      }
 
       bearbeitetRepository.save(bearbeitet);
 
-    return bearbeitet;
+      return new Gson().toJson(bearbeitet);
+
+    } else { // kein angemeldeter User startet den Cache
+      Optional<Cache> cacheOptional = cacheRepository.findById(Integer.valueOf(cacheID));
+      if (cacheOptional.isPresent()) {
+        Cache cache = cacheOptional.get();
+        return new Gson().toJson(cache);
+      } else {
+        return "There is no cache with the ID " + cacheID;
+      }
+    }
   }
 }