java程序设计设计学生累

设计一个学生类，包含学生的姓名、学号、课程数（不可修改）、各门课程的成绩；可以获取学生的学号，但不能修改；可以获取和修改姓名；可以输入和读取成绩；可以获得学生的平均成绩。
写出具体类的成员方法和函数定义，并写出测试的main函数。

public class Student {
    private String name;
    private String sno;
    private Integer cnum;
    private Integer english;
    private Integer math;
    private Integer chinese;

    public Student(String name, String sno, Integer cnum, Integer english, Integer math, Integer chinese) {
        this.name = name;
        this.sno = sno;
        this.cnum = cnum;
        this.english = english;
        this.math = math;
        this.chinese = chinese;
    }

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

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

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

    public void setChinese(Integer chinese) {
        this.chinese = chinese;
    }

    public String getName() {
        return name;
    }

    public String getSno() {
        return sno;
    }

    public Integer getEnglish() {
        return english;
    }

    public Integer getMath() {
        return math;
    }

    public Integer getChinese() {
        return chinese;
    }

    public double avg(){
        return (getEnglish()+getMath()+getChinese())/3.0;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", sno='" + sno + '\'' +
                ", cnum=" + cnum +
                ", english=" + english +
                ", math=" + math +
                ", chinese=" + chinese +
                '}';
    }

    public static void main(String[] args) {
        Student student=new Student("小白","1001",3,88,99,66);
        System.out.println(student);
    }
}