import java.util.Arrays;

/**
 * @author Soap
 * time 2021年04月20日 0:47
 * java.lang 接口 Comparable<T>
 * 可以让自己定义的类实现比较(> < = 等等)
 * 比如比较两个student, 实际上是在比较student.id.
 * 实现Comparable接口后, jdk内自带的如sort方法可实现排序.
 * 1. 如果参数等于this.属性,则返回值 0;
 * 2. 如果此参数小于his.属性,则返回一个小于 0 的值;
 * 3. 如果此参数大于his.属性,则返回一个大于 0 的值。
 */
public class ComparableStudy {
 private static class Student implements Comparable<Student> {
 private int id;
 private String name;

 public Student() {
 }

 public Student(int id, String name) {
 this.id = id;
 this.name = name;
 }

 public String getName() {
 return name;
 }

 public void setName(String name) {
 this.name = name;
 }

 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 @Override
 public int compareTo(Student o) {
 return new Integer(o.getId()).compareTo(this.getId());
 }

 @Override
 public String toString() {
 return "id:" + this.id + " name:" + this.name;
 }
 }

 public static void main(String[] args) {
 Student student1 = new Student(1, "小明");
 Student student2 = new Student(2, "小红");
 Student student3 = new Student(3, "小强");
 Student students[] = {student2, student3, student1};

 System.out.println("小明和小强之间学号更大的是: " + (student1.compareTo(student3) > 0 ? student1.toString() : student3));
 Arrays.sort(students);
 System.out.println("排序后: " + Arrays.toString(students));
 }


}