小實例-實現對成績總分由高到低的排序-Java中數組對象的排序

這個SortTotalScore類的功能是：對於一組由學生班級，姓名，各科成績組成的記錄列表，統計出每個學生的總分，並且按照總分由高到低的順序顯示出學生所有信息。

思路：建立一個由Student類數據組成的一維數組。要對該數組對象的元素進行排序，利用了Arrays類的sort()方法.由於是對象數組，所以Student類必須實現Comparable接口，並且重寫compareTO()方法，否則會拋出異常。

//如何實現這對象數組排序 import java.util.Arrays; public class SortTotalScore { public static void main(String args[]) { Student[] st = new Student[10]; st[0] = new Student ("三年二班", "老大",93,84,54,45,89,66,75); st[1] = new Student ("三年二班", "老二",88,65,48,98,56,44,85); st[2] = new Student ("三年二班", "老三",68,74,59,39,64,77,85); st[3] = new Student ("三年二班", "老四",77,85,49,62,18,46,89); st[4] = new Student ("三年二班", "老五",45,39,56,54,66,39,76); st[5] = new Student ("三年二班", "老六",45,87,35,49,85,41,28); st[6] = new Student ("三年二班", "老七",77,87,41,54,64,48,52); st[7] = new Student ("三年二班", "老八",54,75,41,35,54,87,69); st[8] = new Student ("三年二班", "老九",78,98,74,54,12,68,48); st[9] = new Student ("三年二班", "老十",39,22,65,48,88,98,92); Arrays.sort(st); for (int i = 0; i < st.length; i++) { System.out.println(st[i]); } } } class Student implements Comparable { String banji; String mingzi; int yuwen; int shuxue; int yingwen; int lishi; int zhengzhi; int huaxue; int wuli; Student(String banji,String mingzi,int yuwen,int shuxue, int yingwen,int lishi,int zhengzhi,int huaxue,int wuli) { this.banji = banji; this.mingzi = mingzi; this.yuwen = yuwen; this.shuxue = shuxue; this.yingwen = yingwen; this.lishi = lishi; this.zhengzhi = zhengzhi; this.huaxue = huaxue; this.wuli = wuli; } public int getTotalScore() { return yuwen+shuxue+yingwen+lishi+zhengzhi+huaxue+wuli; } public int compareTo(Object o) { Student s=(Student)o; return getTotalScore()<s.getTotalScore() ? 1:(getTotalScore()==s.getTotalScore() ? 0 :-1); } public String toString() { return "班級：" + this.banji + "名字" + this.mingzi + " 成績:/n"+"語文：" + this.yingwen + "數學：" + this.shuxue + "英文：" + this.yingwen + "歷史：" + this.lishi + "政治：" + this.zhengzhi + "化學：" + this.huaxue + "物理：" + this.wuli+"/n"+"總分："+this.getTotalScore(); } }