Java 8 对象的排序列表

Question

我正在尝试像这样对我的对象列表进行排序：

List<UsersDataFoundTo> mergedUsers = mergeUsersFound(ldapUsers, foundUsers);

return mergedUsers.sort((UsersDataFoundTo h1, UsersDataFoundTo h2) -> h1.getLastName().compareTo(h2.getLastName()));

在 return 语句中我得到一个错误：

Incompatible types.

Required: java.util.List<UsersDataFoundTo>

Found:void

那我做错了什么？

Answer 1

更容易写成：mergedUsers.sort(Comparator.comparing(UsersDataFoundTo::getLastName))并且sort有一个void返回类型，所以基本上做一个：return&nbsp;mergedUsers;

Answer 2

对于可重用，我认为类 UsersDataFoundTo 应该实现 Comparable 并覆盖 compareTo 函数。class UsersDataFoundTo implements Comparable<UsersDataFoundTo> {&nbsp; &nbsp; private String lastNam;&nbsp; &nbsp; public String getLastNam() {&nbsp; &nbsp; &nbsp; &nbsp; return lastNam;&nbsp; &nbsp; }&nbsp; &nbsp; public void setLastNam(String lastNam) {&nbsp; &nbsp; &nbsp; &nbsp; this.lastNam = lastNam;&nbsp; &nbsp; }&nbsp; &nbsp; @Override&nbsp; &nbsp; public int compareTo(UsersDataFoundTo other) {&nbsp; &nbsp; &nbsp; &nbsp; return getLastNam().compareTo(other.getLastNam());&nbsp; &nbsp; }}然后，您可以使用收集实用程序对其进行排序，如下所示：List<UsersDataFoundTo> mergedUsers = //...java.util.Collections.sort(mergedUsers);我希望这会有所帮助。