onDataChange在android Firebase中被调用两次

这是我在 Android应用程序中使用时间戳的firebase数据的简单查询

Query recentStaticJobQuery = reference.child(AppConstants.WORKINDIA_JOBS)
                        .child(AppConstants.WORKINDIA_STATIC_JOBS)
                        .orderByChild(AppConstants.TIMESTAMP)
                        .startAt(lastStaticJobSyncTime); 
recentStaticJobQuery.addListenerForSingleValueEvent
(staticJobDownloadListener);


 ValueEventListener staticJobDownloadListener = new ValueEventListener() {
    @Override
    public void onDataChange(final DataSnapshot dataSnapshot) {
        Log.i("Firebase","Called")
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
        Log.i("Firebase","onCancelled")
    }
};

如何避免onDataChange在android Firebase中被调用两次？

解决方法

使用SingleEventListener而不是ValueEventListener像这样

Firebase ref = new Firebase("YOUR-URL-HERE/PATH/TO/YOUR/STUFF");
ref.addListenerForSingleValueEvent(new ValueEventListener() {
   @Override
   public void onDataChange(DataSnapshot dataSnapshot) {
       String value = (String) dataSnapshot.getValue();
       // do your stuff here with value
   }
   @Override
   public void onCancelled(FirebaseError firebaseError) {
   }
});