関連ワード:  object is empty or null in java    object is empty or not in javascript    check object is empty or null in java    check object is empty or not in javascript    check object is empty or not in java    how to check if object is empty or null in java    javascript object is empty or null    check if object is empty or null javascript    how to check json object is empty or not in javascript    how to check json object is empty or not in java