}
JDK7獲取List中的Id數(shù)據(jù)：

//給List賦值
List<User> list = getList();
//新的IdList
List<String> Ids = new ArrayList<>();
for (User user: list) {
Ids.add(user.getId());
}
JDK8 獲取Id數(shù)據(jù)：