Question

我有一个对象列表List<Student>。

class Student {
 private String name;
 private Integer age;
 private Integer rank

 public String getName() {
  return this.name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public Integer getAge() {
  return this.name;
 }
 public void setAge(Integer age) {
  this.age = age;
 }
 public Integer getRank() {
  return this.rank;
 }
 public void getRank(Integer rank) {
  this.rank = rank;
 }
}

我必须首先根据排名对排序进行排序，如果两个学生的排名相同，那么根据他们的年龄，以及他们的年龄是否相同，然后根据他们的名字。

任何人都可以帮忙吗？感谢

Answer 1

您可以使用java8 lambdas

List<Student> students = new Arraylist<>();
...
...
...
student.sort()

students.sort(Comparator.comparing(Student::getName).thenComparing(Student::getAge));

Answer 2

在java8中，你有.thenComparing(...)方法

Comparator< Student> studentComparator = Comparator.comparing(student -> student.name);
comparator = comparator.thenComparing(Comparator.comparing(student -> student.age));
comparator = comparator.thenComparing(Comparator.comparing(student -> student.rank));

 // Then pass this comparator in Collections#sort method

Collecions.sort(studentList, studentComparator); Your list will be sorted

Answer 3

您可以将Guava用于Java 7以用于相同的用例。

请参阅：https://github.com/google/guava/wiki/CommonObjectUtilitiesExplained#compare/compareTo.md

基于多个参数

3 个答案: