根ID的火力地堡設定鍵

Question

我只是不知道如何設置根ID與我自己的而不是被頂部while循環中產生的推送（）鍵的鍵..

-Waypoint 
    -RootID <-- This key 
     -Points 

....................

LinkedHashMap<String, Object> pointHolder = new LinkedHashMap<>(); 
LinkedHashMap<String, Object> waypointHolder = new LinkedHashMap<>(); 

waypointsUrl = Constants.FIREBASE_URL + "https://stackoverflow.com/users/" + mUserId + "/waypoints"; 
     mainRef = new Firebase(waypointsUrl); 

.................

更新代碼

  while (isFirstTime) { 
       // Generates root id for date 
       DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
       Date date = new Date(); 
       mLastUpdateTime = dateFormat.format(date); 

       // Generates root id 
       mainRefKey = mainRef.push(); 

       isFirstTime = false; 
      } 


      // Generates new id for point 
      Firebase wayRef1 = mainRefKey.push(); 
      String pointKey = wayRef1.getKey(); 


      // Create Waypoint > Point > put lat and lon 
      LinkedHashMap<String, Object> latLng = new LinkedHashMap<String, Object>(); 
      latLng.put("latitude", 123); 
      latLng.put("longitude", 123); 


      // Puts lat and lon ** under a Point Key ** 
      pointHolder.put(pointKey, latLng); 


      // Waypoint > POINT (contains multiple points) 
      waypointHolder.put("points", pointHolder); 
      waypointHolder.put("timeStamp", "24/3-2016"); 
      waypointHolder.put("travelType", "travel"); 


      // ROOT ID > Waypoint 
      mainRefKey.updateChildren(waypointHolder); 
     } 
    }); 

圖片所需的結構：

Answer 1

我建議檢查出的docs on saving data並通過api docs

閱讀改變你的循環執行以下操作：

while (isFirstTime) { 
    // Generates root id for date 
    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
    Date date = new Date(); 
    mLastUpdateTime = dateFormat.format(date); 

    // Generates root id 
    mainRefKey = mainRef.child(mLastUpdateTime); 


    isFirstTime = false; 
}