Java 8 Comparator链接单个属性的反向

Question

我用a Comparator来排序Student对象列表.

我想反转id属性的排序,但using reverse()方法将它应用于整个排序.

怎么让它发生在id？

到目前为止,这是我的代码:

 public List<Student> getStudents(List<String> events) {
    Comparator<Student> comparatorStudents = Comparator.comparing(Student::getCGPA).thenComparing(Student::getName)
      .thenComparingInt(Student::getID).reverse();
    List<Student> students = new ArrayList<Student>();
    //Filling students
    Collections.sort(students, comparatorStudents);
    return students;
  }

Answer 1

将最后一位更改为:

.thenComparing(Student::getID, Comparator.reverseOrder())

或者,如果您想避免自动装箱:

.thenComparing(Comparator.comparingInt(Student::getID).reversed())

Answer 2

reversed()将内部调用thenComparing：

public List<Student> getStudents(List<String> events) {
    Comparator<Student> comparatorStudents = Comparator.comparing(Student::getCGPA)
       .thenComparing(Student::getName)
       .thenComparing(Comparator.comparingInt(Student::getID).reversed());
    List<Student> students = new ArrayList<Student>();
    //Filling students
    Collections.sort(students, comparatorStudents);
    return students;
}