diff --git a/app/src/main/java/com/example/cosmosclient/app/Cosmos.java b/app/src/main/java/com/example/cosmosclient/app/Cosmos.java
index d5c271d..15440c3 100644
--- a/app/src/main/java/com/example/cosmosclient/app/Cosmos.java
+++ b/app/src/main/java/com/example/cosmosclient/app/Cosmos.java
@@ -17,6 +17,21 @@
     private HashMap<String, Group> groups = new HashMap<>();
     private String uId=null;
     private HashMap<Integer, AreaInformation> areaInfo = new HashMap<>();
+    public Cosmos() {
+        registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
+            @Override
+            public void onActivityStopped(Activity activity) {
+            }
+            
+            @Override
+            public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
+            }
+             
+            @Override
+            public void onActivityDestroyed(Activity activity) {
+            }
+        });
+    }
 
     //token処理
     public void setToken(String token){