基于idea-学生管理系统(list)，包含五门课的成绩。

学生的类，有学生的性别，籍贯，姓名和五门课程的成绩，用private进行封装，同时写出getter和setter方法

package com.zheng.people;

public class Student {
    private String name;
    private String jiguan;
    private String number;//学生学号
    private String gender;//性别
    private String classname;//学生班级
    private int age;//
    private double english;//英语成鸡
    private double math;//数学成绩
    private double cscore;//c语言成绩
    private double javascore;//java成绩
    private double PE;//体育成绩
    private double total;//总成绩
    private double avergae;//平均成绩
    public Student(){

    }

    public String getJiguan() {
        return jiguan;
    }

    public double getAvergae() {
        return avergae;
    }

    public void setAvergae(double avergae) {
        this.avergae = avergae;
    }

    public double getTotal() {
        return total;
    }

    public void setTotal(double total) {
        this.total = total;
    }

    public void setJiguan(String jiguan) {
        this.jiguan = jiguan;
    }

    public String getName() {
        return name;
    }
    public Student(String name,String number,String gender,String classname,int age,double english,double math,double cscore,double javascore,double PE,double avergae,double total){
        this.age=age;
        this.classname=classname;
        this.gender=gender;
        this.number=number;
        this.name=name;
        this.cscore=cscore;
        this.english=english;
        this.javascore=javascore;
        this.PE=PE;
        this.math=math;
        this.avergae=avergae;
        this.total=total;
    }

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

    public String getNumber() {
        return number;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public void setNumber(String number) {
        this.number=number;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getClassname() {
        return classname;
    }

    public void setClassname(String classname) {
        this.classname = classname;
    }

    public double getPE() {
        return PE;
    }

    public void setPE(double PE) {
        this.PE = PE;
    }

    public double getJavascore() {
        return javascore;
    }

    public void setJavascore(double javascore) {
        this.javascore = javascore;
    }

    public double getCscore() {
        return cscore;
    }

    public void setCscore(double cscore) {
        this.cscore = cscore;
    }

    public double getMath() {
        return math;
    }

    public void setMath(double math) {
        this.math = math;
    }

    public double getEnglish() {
        return english;
    }

    public void setEnglish(double english) {
        this.english = english;
    }


    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", jiguan='" + jiguan + '\'' +
                ", number='" + number + '\'' +
                ", gender='" + gender + '\'' +
                ", classname='" + classname + '\'' +
                ", age=" + age +
                ", english=" + english +
                ", math=" + math +
                ", cscore=" + cscore +
                ", javascore=" + javascore +
                ", PE=" + PE +
                ", total=" + total +
                ", avergae=" + avergae +
                '}';
    }
}

coust类提示操作成功和失败！

package com.zheng.util;

public class COUST {
    public static final String SUCCESS="操作成功";
    public static final String ERROR="操作失败";
}

Result类

package com.zheng.util;


import com.sun.org.apache.regexp.internal.RE;

import java.sql.ResultSet;
import java.util.HashMap;
import java.util.Map;


    public class Result {
        private int code;
        private String message;
        private Map<String,Object> data=new HashMap<>();

        public Result() {
        }

        public Result(int code, String message, Map<String, Object> data) {
            this.code = code;
            this.message = message;
            this.data = data;
        }

        public int getCode() {
            return code;
        }

        public void setCode(int code) {
            this.code = code;
        }

        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }

        public Map<String, Object> getData() {
            return data;
        }

        public void setData(Map<String, Object> data) {
            this.data = data;
        }

        @Override
        public String toString() {
            return "Result{" +
                    "code=" + code +
                    ", message='" + message + '\'' +
                    ", data=" + data +
                    '}';
        }
        public static Result ok(){
            Result r=new Result();
            r.setCode(ResultCode.SUCCESS);
            r.setMessage(COUST.SUCCESS);
            return r;
        }
        public static Result error(){

            Result r=new Result();
            r.setCode(ResultCode.ERROR);
            r.setMessage(COUST.ERROR);
            return r;
        }
        public Result message(String message){
            this.setMessage(message);
            return this;
        }
        public Result code(Integer code){
            this.setCode(code);
            return this;
        }
        public Result data(String key,Object value){
            this.data.put(key,value);
            return this;
        }
        public Result data(Map<String,Object> map){
            this.setData(map);
            return this;
        }
    }

ResultCode类

package com.zheng.util;

public class ResultCode {
    public static Integer SUCCESS=200;
    public static Integer ERROR=201;
}

StudnetUtils类，采用随机数法模拟班级成员，但这样会使班级成员分数较低，仅仅是模拟

package com.zheng.util;

import com.zheng.people.Student;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;//采用随机数发给随机的学生赋值；

public class StudentUtils {
    public static List<Student> studentList(){
        List<Student> students=new ArrayList<>();
        for (int i = 0; i < 15; i++) {
            Student s=new Student();
            Random r = new Random();
            s.setName("张"+i);
            s.setJiguan(i>5?"陕西":"河南");
            s.setNumber("2109124000"+i);
            s.setGender(i>5?"男":"女");
            s.setClassname("计算机2101班");
            s.setAge(18);
            double english= r.nextDouble()*100;
            s.setEnglish(english);
            double math=r.nextDouble()*100;
            s.setMath(math);
            double PE=r.nextDouble()*100;
            s.setPE(PE);
            double java=r.nextDouble()*100;
            s.setJavascore(java);
            double c=r.nextDouble()*100;
            s.setCscore(c);
            s.setTotal(english+math+PE+java+c);
            s.setAvergae((english+math+PE+java+c)/5);
            students.add(s);
        }

return students;
    }
}

StudentInterface类创建学生的接口（比较草率的写了，应该在写查找和修改的）

package com.zheng.service;

import com.zheng.people.Student;
import com.zheng.util.Result;

import java.util.List;


public interface StudentInterface {
    /**
     * 增加一个学生
     *
     * @param stu
     * @param list
     * @return
     */
    public static Result addStudent(Student stu, List<Student> list) {
        return null;
    }   

    /**
     * 这个方法是删除一个学生
     * @param stu
     * @param list
     * @return
     */
    public Result deleteStudent(Student stu, List<Student> list);
    //修改学生。查询学生
}

Studentcaozuo类，重写接口的方法add，delete，search和recover（修改）的方法
有一个问题，在修改学生的成绩后怎么样把单位学生的总体成绩和平均成绩修改？？？（修改单个成绩后，total成绩应该有变动）

package com.zheng.service;

import com.zheng.people.Student;
import com.zheng.service.StudentInterface;
import com.zheng.util.Result;

import java.util.List;
import java.util.Scanner;


public class Studentcaozuo implements StudentInterface {


    public static Result addStudent(Student stu, List<Student> list) {
        list.add(stu);
        return Result.ok().data("studentList", list);
    }


    public Result deleteStudent(Student stu, List<Student> list) {
        for (Student student : list) {
            if (stu.getName().equals(student.getName())) {
                list.remove(student);
                return Result.ok();
            }

        }
        return Result.error();
    }

    public Result searchStudent(Student stu, List<Student> StudentProject) {
        for(Student student02:StudentProject)
        {
            if(stu.getName().equals(student02.getName()))
                System.out.println("查到的结构为"+student02);
            return Result.ok();
        }
        Result.error();
        return null;
    }

   
    public Result recover(Student stu,String need, List<Student> StudentProject) {
        for(Student s03:StudentProject)
            if(stu.getName().equals(s03.getName()))
                switch (need)
                {
                    case"姓名":

                    System.out.print("请输入姓名");
                    Scanner Q = new Scanner(System.in);
                    String name;
                    name = Q.next();
                    s03.setName(name);break;
                    case"籍贯":
                    System.out.print("请输入籍贯");
                    Scanner W = new Scanner(System.in);
                    String jiguan;
                    jiguan = W.next();
                        s03.setJiguan(jiguan);break;
                    case"学号":
                    System.out.print("请输入学生学号");
                    Scanner E = new Scanner(System.in);
                    String number;
                    number = E.next();
                        s03.setNumber(number);break;
                    case"性别":
                    System.out.print("请输入性别");
                    Scanner R = new Scanner(System.in);
                    String gender;
                    gender = R.next();
                        s03.setGender(gender);break;
                    case"班级":
                    System.out.print("请输入学生班级");
                    Scanner T = new Scanner(System.in);
                    String Classname;
                    Classname = T.next();
                        s03.setClassname(Classname);break;
                    case"年龄":
                    System.out.print("请输入学生年龄");
                    Scanner Y = new Scanner(System.in);
                    int age;
                    age = Y.nextInt();
                        s03.setAge(age);break;

                    case"英语成绩":
                        System.out.print("请输入英语成绩");
                    Scanner U = new Scanner(System.in);
                    double English;
                    English = U.nextDouble();
                        s03.setEnglish(English);break;

                    case"数学成绩":
                        System.out.print("请输入数学成绩");
                    Scanner I = new Scanner(System.in);
                    double Math;
                    Math = I.nextDouble();
                        s03.setMath(Math);break;
                    case"c语言成绩":
                    System.out.print("请输入c语言成绩");
                    Scanner O = new Scanner(System.in);
                    double C;
                    C = O.nextDouble();
                        s03.setCscore(C);break;
                    case"java成绩":
                    System.out.print("请输入java成绩");
                    Scanner P = new Scanner(System.in);
                    double Java;
                    Java = P.nextDouble();
                        s03.setJavascore(Java);break;
                    case"体育成绩":
                    System.out.print("请输入体育成绩");
                    Scanner A = new Scanner(System.in);
                    double PE;
                    PE = A.nextDouble();
                        s03.setPE(PE);
                    ;break;



                    default:
                        System.out.println("输入错误");
                }
        return null;
}}

测试类如下

package com.zheng.Text;


import com.zheng.people.Student;
import com.zheng.service.Studentcaozuo;
import com.zheng.util.Result;
import com.zheng.util.StudentUtils;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;


public class StudentText {
    public static void main(String[] args) {

        Scanner n = new Scanner(System.in);
        List<Student> list = new ArrayList<>();
        list = StudentUtils.studentList();//这个list已经赋值了，随机数法模拟班级成绩（班级成绩很低）
        Studentcaozuo studentservice = new Studentcaozuo();
        Result Result;
        int choice=0;
        while(true) {
            System.out.println("请输入操作数");
            System.out.println("【1】增加学生");
            System.out.println("【2】删除学生");
            System.out.println("【3】修改学生");
            System.out.println("【4】查找学生");
            System.out.println("【5】显示所有学生");
            System.out.println("【6】平均成绩及格的学生");
            choice = n.nextInt();
            switch (choice) {
                case 1:
                    System.out.println("添加学生");
                    Student s01 = new Student();
                    System.out.print("请输入姓名");
                    Scanner q = new Scanner(System.in);
                    String name;
                    name = q.next();
                    s01.setName(name);
                    System.out.print("请输入籍贯");
                    Scanner w = new Scanner(System.in);
                    String jiguan;
                    jiguan = w.next();
                    s01.setJiguan(jiguan);
                    System.out.print("请输入学生学号");
                    Scanner e = new Scanner(System.in);
                    String number;
                    number = w.next();
                    s01.setNumber(number);
                    System.out.print("请输入性别");
                    Scanner r = new Scanner(System.in);
                    String gender;
                    gender = r.next();
                    s01.setGender(gender);
                    System.out.print("请输入学生班级");
                    Scanner t = new Scanner(System.in);
                    String Classname;
                    Classname = t.next();
                    s01.setClassname(Classname);
                    System.out.print("请输入学生年龄");
                    Scanner y = new Scanner(System.in);
                    int age;
                    age = y.nextInt();
                    s01.setAge(age);
                    System.out.print("请输入英语成绩");
                    Scanner u = new Scanner(System.in);
                    double english;
                    english = u.nextDouble();
                    s01.setEnglish(english);
                    System.out.print("请输入数学成绩");
                    Scanner i = new Scanner(System.in);
                    double math;
                    math = i.nextDouble();
                    s01.setMath(math);
                    System.out.print("请输入c语言成绩");
                    Scanner o = new Scanner(System.in);
                    double c;
                    c = o.nextDouble();
                    s01.setCscore(c);
                    System.out.print("请输入java成绩");
                    Scanner p = new Scanner(System.in);
                    double java;
                    java = p.nextDouble();
                    s01.setJavascore(java);
                    System.out.print("请输入体育成绩");
                    Scanner a = new Scanner(System.in);
                    double PE;
                    PE = a.nextDouble();
                    s01.setPE(PE);
                    s01.setTotal(PE + java + c + math + english);
                    s01.setAvergae((PE + java + c + math + english) / 5);
                    Result=studentservice.addStudent(s01,list);
                    System.out.println("新的学生已经添加！");
                    break;
                case 2:System.out.print("删除学生信息：");
                Student s02=new Student();
                String name02;
                System.out.print("请输入想删除的学生姓名");
                name02=n.next();
                s02.setName(name02);
                Result=studentservice.deleteStudent(s02,list);break;
                case 3:
                    System.out.print("修改学生信息:");
                    Student s03=new Student();
                    System.out.print("请输入要修改学生的姓名:");
                    String name03;
                    name03=n.next();
                    s03.setName(name03);
                    System.out.print("请输入需要修改的信息类型:");
                    String need;
                    need =n.next();
                    studentservice.recover(s03,need,list);break;
                case 4:      System.out.println("查找学生信息");
                    Student s04 = new Student();
                    System.out.print("请输入学生的姓名：");
                    String name04 = n.next();
                    s04.setName(name04);
                    studentservice.searchStudent(s04,list);
                    break;

                case 5:
                    if (list.size() == 0) {
                        System.out.print("表内还没有学生");
                    } else {
                        System.out.println("展示班级所有学生");
                        for (int count = 0; count < list.size(); count++) {
                            System.out.println(list.get(count));
                        }
                    }break;
                case 6:
                    if (list.size() == 0) {
                        System.out.print("表内还没有学生");
                    } else {
                        System.out.println("平均成绩及格的学生如下");
                        for (int count = 0; count < list.size(); count++) {
                            if(list.get(count).getAvergae()>60)
                            System.out.println(list.get(count));
                        }
                    }


            }
        }
    }
}

如下是测试结果