本学生信息管理系统代码主要实现以下 5 个主功能:"1。添加一个学生");”2。根据学号/姓名查找一个学生”);"3。根据学号更新一个学生信息”);”4。根据学号删除学生信息”);”5。根据学号输入学生成绩"); ”99.退出");副功能主动显示计算平均分和总成绩(还需添加其他功能代码,请联系)public class Student {private String name;private String xuehao;private int age;private int index;private int math;private int chinese;private int english;private int wuli;private int huaxue;private int shengwu;private int sum;private int avg;public void setIndex(int index){this.index=index;}public int getIndex(){return this。index;}public void setName(String name){//设置名字this。name=name;}public String getName(){return this.name;}public void setAge(int age){this.age=age;}public int getAge(){return this。age;}public void setXuehao(String xuehao){//设置学号this。xuehao=xuehao;}public String getXuehao(){return this。xuehao;}public void setMath(int math){this.math=math;}public int getMath(){return this.math;}public void setChinese(int chinese){this。chinese=chinese;}public int getChinese(){return this.chinese;}public void setEnglish(int english){this。english=english;}public int getEnglish(){return this。english;}public void setWuli(int wuli){this。wuli=wuli;}public int getWuli(){return this.wuli;}public void setHuaxue(int huaxue){this.huaxue=huaxue;}public int getHuaxue(){return this.huaxue;}public void setShengwu(int shengwu){this。shengwu=shengwu;}public int getShengwu(){return this.shengwu;}public void setSum(){this。sum=this.math+this。chinese+this。english+this.wuli+this。huaxue+this.shengwu;}public int getSum(){return this.sum;}public void setAvg(){this.avg=sum/6;}public int getAvg(){return this.avg;}public String toString(){String msg="\t”+this.xuehao+”\t\t"+this。name+”\t”+this.age+"\t"+this.math+”\t"+this.chine...