Java中比较器Comparator和Comparable的区别

public interface Comparable<T>

public class Student implements Comparable<Object> {
    String name;
    int age;
    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    @Override
    public String toString() {
        return "{" + this.getName() + "," + this.getAge() + "}";
    }
    // 通过重写 compareTo 方法，实现比较器
    @Override
    public int compareTo(Object o) {
        Student student = (Student) o;
        return this.age - student.getAge();
    }
    public static void main(String[] args) {
        List<Student> list = new ArrayList<>();
        list.add(new Student("wanqing", 21));
        list.add(new Student("xinyu", 23));
        list.add(new Student("huahua", 1));
        Collections.sort(list);
        System.out.println(list);
    }
}

Collections.sort(List<T> list, Comparator<? super T> c);
Arrays.sort(T[] a, Comparator<? super T> c);

    public static void main(String[] args) {
        List<Student> list = new ArrayList<>();
        list.add(new Student("wanqing", 21));
        list.add(new Student("xinyu", 23));
        list.add(new Student("huahua", 1));
        // 实现对 list 按照学生年龄降序排序
        Collections.sort(list, new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                // 降序排序
                return o2.getAge() - o1.getAge();
            }
        });
        System.out.println(list);
    }