연결이 안 되는 것과 입력이 잘못된 것 구분

@@ -103,8 +103,7 @@ public class Api {
     static public void auth(String doorId, final Callback callback) {
         if("123123123".equals(doorId)) {
             // 테스트를 위한 super pass
-            callback.callbackMethod(true);
-            Api.accessToken = "superpass";
+            callback.callbackMethod(new Auth(true, "superpass"));
             return;
         }
 
@@ -118,10 +117,12 @@ public class Api {
                     JsonObject resp = (JsonObject) apiResult.getData();
                     if(resp.get("is_available").getAsBoolean()) {
                         callback.callbackMethod(new Auth(true, resp.get("access_token").getAsString()));
-                        return;
+                    } else {
+                        callback.callbackMethod(new Auth(false));
                     }
+                } else {
+                    callback.callbackMethod(null);
                 }
-                callback.callbackMethod(new Auth(false));
             }
         });
     }

@@ -81,6 +81,11 @@ public class SplashActivity extends AppCompatActivity {
                         @Override
                         public void callbackMethod(Object obj) {
                             Auth auth = (Auth) obj;
+                            if(auth == null) {
+                                Toast.makeText(getApplicationContext(),"연결 상태가 불안정합니다.",Toast.LENGTH_SHORT).show();
+                                return;
+                            }
+
                             if(auth.getIsAvailable()) {
                                 SharedPreferences pref = getSharedPreferences("gateway", MODE_PRIVATE);
                                 SharedPreferences.Editor editor = pref.edit();