diff --git a/src/main/java/org/ntlab/tampoposerver/repositories/NotificationRepository.java b/src/main/java/org/ntlab/tampoposerver/repositories/NotificationRepository.java
index 0bc32e6..0c427de 100644
--- a/src/main/java/org/ntlab/tampoposerver/repositories/NotificationRepository.java
+++ b/src/main/java/org/ntlab/tampoposerver/repositories/NotificationRepository.java
@@ -3,21 +3,26 @@
 import org.ntlab.tampoposerver.models.Notification;
 import org.springframework.stereotype.Repository;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
+import java.util.*;
 
 @Repository
 public class NotificationRepository {
     private HashMap<String, HashMap<String, Notification>> notificationMap = new HashMap<>();
 
     //通知の追加
-    public Notification addNotification(String userId, String notificationId, String from, String text, String time) {
+    public Notification addNotification(String userId, String from, String text, String time) {
+        String notificationId;
+        Map<String, Notification> userNotifications = notificationMap.get(userId);
+        if (userNotifications == null) {
+            notificationId = Integer.toString(0);
+        }
+        else{
+            notificationId = Integer.toString(userNotifications.size());
+        }
+
         Notification n = new Notification(userId, notificationId, from, text, time);
 
-        if(notificationMap.get(userId) == null) {
+        if(userNotifications == null) {
             notificationMap.put(userId, new HashMap<>());
         }
         notificationMap.get(userId).put(notificationId, n);
@@ -40,8 +45,36 @@
             return new ArrayList<>();
         }
 
-        return userNotifications.values().stream()
-                .sorted((a, b) -> b.getTime().compareTo(a.getTime()))
-                .collect(Collectors.toList());
+        List<Notification> sortedNotifications = new ArrayList<>(userNotifications.values());
+
+        Collections.sort(sortedNotifications, new Comparator<Notification>() {
+            @Override
+            public int compare(Notification o1, Notification o2) {
+                if(o1.getTime().compareTo(o2.getTime()) < 0) {
+                    return 1;
+                }
+                else if(o1.getTime().compareTo(o2.getTime()) > 0) {
+                    return -1;
+                }
+                return 0;
+            }
+        });
+
+//        for(int i = 0; i < sortedNotifications.size() - 1; i++) {
+//            for(int j = i + 1; j < sortedNotifications.size(); j++) {
+//                if(sortedNotifications.get(i).getTime().compareTo(sortedNotifications.get(j).getTime()) < 0) {
+//                    Notification tmp = sortedNotifications.get(i);
+//                    sortedNotifications.set(i, sortedNotifications.get(j));
+//                    sortedNotifications.set(j, tmp);
+//                }
+//            }
+//        }
+
+        return sortedNotifications;
+
+//        ラムダ式
+//        return userNotifications.values().stream()
+//                .sorted((a, b) -> b.getTime().compareTo(a.getTime()))
+//                .collect(Collectors.toList());
     }
 }