Compareble 接口与Comparator接口比较

Compareble接口

     可以直接通过Arrays.sort 对数组进行排序

import java.util.Arrays;public class Student implements Comparable<Student> {private String name;private int age;private int score;public Student(String name, int age, int score) {super();this.name = name;this.age = age;this.score = score;}  @Overridepublic String toString() {return "Student [name=" + name + ", age=" + age + ", score=" + score+ "]";}@Overridepublic int compareTo(Student o) {// TODO Auto-generated method stubif (this.age < o.age) {return -1;}if (this.age > o.age) {return 1;} else {if (this.score < o.score) {return -1;}if (this.score > o.score) {return 1;}}return 0;}      public static void main(String[] args) {Student  stu[]={new Student("马超", 68, 88),new Student("赵云", 30, 90),new Student("关二个", 33, 99),new Student("张飞",32, 92)};Arrays.sort(stu);for (int i = 0; i < stu.length; i++) {System.out.println(stu[i]);}}}

输入结果 Student [name=赵云, age=30, score=90]
Student [name=张飞, age=32, score=92]
Student [name=关二个, age=33, score=99]
Student [name=马超, age=68, score=88]
如果 Student类没有实现comparable 则会抛出Student cannot be cast to java.lang.Comparable （student类不能被抛到java.lang.Comparable ）说明arrays.sort()实现是根据compareble进行数组排序的。引用一老兄的话：java中的对象排序永远都是以Comparable 接口为标准的。、

另一种比较器 comparator  

comparator接口中实现的方法

compare（T o1,To2）---比较用来比较的2个参数

compare 主要作用是用来对已经写好的类，但是没有实现comparable 接口进行的补充。

http://blog.csdn.net/cz1029648683/article/details/6666855  一位老兄的文章。