java 代码编写一个学生成绩管理系统。学生的属性包括学号、姓名、年龄等。每个学生要学习若干课程，每门课程有平时成绩、其中考试成绩、实习成绩、期末考试成绩以及总评成绩等多个成绩，其中平时成绩的数目不定（因为不同课程的教师布置的平时作业不同），而总评成绩是其它成绩的平均值。请先设计合理的类存放这些信息，然后设计程序完成以下功能： （1）列出某个学生的所有成绩； （2）列出某门课程每个学生的总评成绩，及所有学生总评成绩的总评分； （3）分区段统计某门课程的学生总评成绩，例如60分以下的学生人数、60至70分的学生人数等。

以下是一个Java代码示例，实现了学生成绩管理系统的基本功能：

import java.util.ArrayList;

class Student {
    private int id;
    private String name;
    private int age;
    private ArrayList<Course> courses;
    
    public Student(int id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
        courses = new ArrayList<>();
    }
    
    public void addCourse(Course course) {
        courses.add(course);
    }
    
    public ArrayList<Course> getCourses() {
        return courses;
    }
    
    public String toString() {
        return "Student ID: " + id + "\nName: " + name + "\nAge: " + age;
    }
}

class Course {
    private String name;
    private ArrayList<Double> dailyGrades;
    private double midtermGrade;
    private double internshipGrade;
    private double finalGrade;
    
    public Course(String name) {
        this.name = name;
        dailyGrades = new ArrayList<>();
    }
    
    public void addDailyGrade(double grade) {
        dailyGrades.add(grade);
    }
    
    public void setMidtermGrade(double grade) {
        this.midtermGrade = grade;
    }
    
    public void setInternshipGrade(double grade) {
        this.internshipGrade = grade;
    }
    
    public void setFinalGrade(double grade) {
        this.finalGrade = grade;
    }
    
    public double getTotalGrade() {
        double total = midtermGrade + internshipGrade + finalGrade;
        for (double grade : dailyGrades) {
            total += grade;
        }
        double avg = total / (dailyGrades.size() + 3);
        return avg;
    }
    
    public String toString() {
        return "Course Name: " + name;
    }
}

class GradeManager {
    private ArrayList<Student> students;
    private ArrayList<Course> courses;
    
    public GradeManager() {
        students = new ArrayList<>();
        courses = new ArrayList<>();
    }
    
    public void addStudent(Student student) {
        students.add(student);
    }
    
    public void addCourse(Course course) {
        courses.add(course);
    }
    
    public void printStudentGrades(Student student) {
        System.out.println(student);
        for (Course course : student.getCourses()) {
            System.out.println(course);
            System.out.println("Total Grade: " + course.getTotalGrade());
        }
    }
    
    public void printCourseGrades(Course course) {
        System.out.println(course);
        double totalGrades = 0;
        for (Student student : students) {
            for (Course c : student.getCourses()) {
                if (c == course) {
                    double grade = c.getTotalGrade();
                    System.out.println(student + "\nTotal Grade: " + grade);
                    totalGrades += grade;
                    break;
                }
            }
        }
        double avgGrade = totalGrades / students.size();
        System.out.println("Average Total Grade: " + avgGrade);
    }
    
    public void printGradeDistribution(Course course) {
        int[] count = new int[11];
        for (Student student : students) {
            for (Course c : student.getCourses()) {
                if (c == course) {
                    double grade = c.getTotalGrade();
                    int index = (int) (Math.floor(grade / 10) - 5);
                    count[index]++;
                    break;
                }
            }
        }
        System.out.println(course);
        int lowerBound = 0;
        for (int i = 0; i < 11; i++) {
            int upperBound = lowerBound + 9;
            if (i == 10) {
                upperBound = 100;
            }
            System.out.println(lowerBound + " - " + upperBound + ": " + count[i]);
            lowerBound = upperBound + 1;
        }
    }
}

public class Main {
    public static void main(String[] args) {
        GradeManager manager = new GradeManager();
        
        // add students
        Student s1 = new Student(1, "Alice", 20);
        Student s2 = new Student(2, "Bob", 21);
        manager.addStudent(s1);
        manager.addStudent(s2);
        
        // add courses
        Course c1 = new Course("Math");
        Course c2 = new Course("English");
        manager.addCourse(c1);
        manager.addCourse(c2);
        
        // add grades
        s1.addCourse(c1);
        c1.addDailyGrade(80);
        c1.addDailyGrade(70);
        c1.addMidtermGrade(85);
        c1.setInternshipGrade(90);
        c1.setFinalGrade(95);
        
        s1.addCourse(c2);
        c2.addDailyGrade(90);
        c2.addMidtermGrade(80);
        c2.setInternshipGrade(95);
        c2.setFinalGrade(85);
        
        s2.addCourse(c1);
        c1.addDailyGrade(75);
        c1.addMidtermGrade(90);
        c1.setInternshipGrade(80);
        c1.setFinalGrade(85);
        
        s2.addCourse(c2);
        c2.addMidtermGrade(70);
        c2.setInternshipGrade(80);
        c2.setFinalGrade(75);
        
        // print grades
        manager.printStudentGrades(s1);
        manager.printCourseGrades(c1);
        manager.printGradeDistribution(c2);
    }
}

这个程序实现了以下功能：

1. 添加学生和课程，并为每个学生添加所学的课程以及对应的成绩；
2. 计算并打印出某个学生的所有成绩；
3. 计算并打印出某门课程每个学生的总评成绩，以及所有学生总评成绩的平均值；
4. 分区段统计某门课程的学生总评成绩，并打印出不同分数段的学生人数。