Java8對多個欄位排序

建立User物件

public class Users {

    private Long id;
    private String name;
    private String code;
    private Long supId;
    private List<Users> usersList;

    public Users() {
    }

    public Users(Long id, String name, String code, Long supId) {
        this.id = id;
        this.name = name;
        this.code = code;
        this.supId = supId;
    }

}
 

編寫測試類

public class Demo01 {
    List<Users> usersList = new ArrayList<>();
    @Before
    public void generateData() {
        usersList.add(new Users(1l, "張三", "20", 0L));
        usersList.add(new Users(2l, "李四1", "22", 1L));
        usersList.add(new Users(4l, "王五1", "20", 2L));
        usersList.add(new Users(3l, "李四2", "20", 1L));
        usersList.add(new Users(6l, "王五3", "22", 2L));
        usersList.add(new Users(5l, "王五2", "21", 2L));
        usersList.add(new Users(7l, "王五4", "23", 2L));
    }

    @Test
    public void demo1() {
        List<Users> collect = usersList.stream().sorted(Comparator.comparing(Users::getSupId).thenComparing(Users::getCode)).collect(Collectors.toList());
        for (Users users : collect) {
            System.out.println(users);
        }
    }

}
 

以上程式碼含義是：通過supId欄位進行排序，如果supId相同則按照code欄位排序。結果集：

Users{id=1, name='張三', code='20', supId=0}
Users{id=3, name='李四2', code='20', supId=1}
Users{id=2, name='李四1', code='22', supId=1}
Users{id=4, name='王五1', code='20', supId=2}
Users{id=5, name='王五2', code='21', supId=2}
Users{id=6, name='王五3', code='22', supId=2}
Users{id=7, name='王五4', code='23', supId=2}