设计一个java代码实现：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。

以下是一个简单的学生成绩管理系统的Java代码实现，其中包括了学生、课程和成绩等类，并实现了上述三个功能：

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

class Student {
    private String id;
    private String name;
    private int age;
    private List<CourseResult> courseResults;

    public Student(String id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.courseResults = new ArrayList<>();
    }

    public void addCourseResult(CourseResult courseResult) {
        this.courseResults.add(courseResult);
    }

    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public List<CourseResult> getCourseResults() {
        return courseResults;
    }
}

class Course {
    private String name;
    private List<CourseResult> courseResults;

    public Course(String name) {
        this.name = name;
        this.courseResults = new ArrayList<>();
    }

    public void addCourseResult(CourseResult courseResult) {
        this.courseResults.add(courseResult);
    }

    public String getName() {
        return name;
    }

    public List<CourseResult> getCourseResults() {
        return courseResults;
    }
}

class CourseResult {
    private Student student;
    private Course course;
    private List<Double> dailyScores;
    private double midtermScore;
    private double internshipScore;
    private double finalScore;

    public CourseResult(Student student, Course course, List<Double> dailyScores, double midtermScore,
                        double internshipScore, double finalScore) {
        this.student = student;
        this.course = course;
        this.dailyScores = dailyScores;
        this.midtermScore = midtermScore;
        this.internshipScore = internshipScore;
        this.finalScore = finalScore;
    }

    public Student getStudent() {
        return student;
    }

    public Course getCourse() {
        return course;
    }

    public List<Double> getDailyScores() {
        return dailyScores;
    }

    public double getMidtermScore() {
        return midtermScore;
    }

    public double getInternshipScore() {
        return internshipScore;
    }

    public double getFinalScore() {
        return finalScore;
    }

    public double getTotalScore() {
        double total = 0;
        for (double score : dailyScores) {
            total += score;
        }
        total += midtermScore + internshipScore + finalScore;
        return total / (dailyScores.size() + 3);
    }
}

class StudentManagementSystem {
    private Map<String, Student> students;
    private Map<String, Course> courses;

    public StudentManagementSystem() {
        this.students = new HashMap<>();
        this.courses = new HashMap<>();
    }

    public void addStudent(Student student) {
        this.students.put(student.getId(), student);
    }

    public void addCourse(Course course) {
        this.courses.put(course.getName(), course);
    }

    public void addCourseResult(CourseResult courseResult) {
        courseResult.getStudent().addCourseResult(courseResult);
        courseResult.getCourse().addCourseResult(courseResult);
    }

    public void printStudentResults(String studentId) {
        Student student = this.students.get(studentId);
        if (student != null) {
            System.out.println("学生：" + student.getName() + " 的成绩如下：");
            for (CourseResult courseResult : student.getCourseResults()) {
                System.out.println(courseResult.getCourse().getName() + " 课程：");
                System.out.println("平时成绩：" + courseResult.getDailyScores());
                System.out.println("期中考试成绩：" + courseResult.getMidtermScore());
                System.out.println("实习成绩：" + courseResult.getInternshipScore());
                System.out.println("期末考试成绩：" + courseResult.getFinalScore());
                System.out.println("总评成绩：" + courseResult.getTotalScore());
                System.out.println();
            }
        } else {
            System.out.println("未找到该学生！");
        }
    }

    public void printCourseResults(String courseName) {
        Course course = this.courses.get(courseName);
        if (course != null) {
            System.out.println(courseName + " 课程的总评成绩如下：");
            double totalScore = 0;
            int count = 0;
            for (CourseResult courseResult : course.getCourseResults()) {
                double score = courseResult.getTotalScore();
                totalScore += score;
                count++;
                System.out.println(courseResult.getStudent().getName() + " 的总评成绩：" + score);
            }
            double avgScore = totalScore / count;
            System.out.println("所有学生总评成绩的总评分：" + avgScore);
        } else {
            System.out.println("未找到该课程！");
        }
    }

    public void printCourseResultsByRange(String courseName, double start, double end) {
        Course course = this.courses.get(courseName);
        if (course != null) {
            int count = 0;
            for (CourseResult courseResult : course.getCourseResults()) {
                double score = courseResult.getTotalScore();
                if (score >= start && score < end) {
                    count++;
                }
            }
            System.out.println(courseName + " 课程总评成绩在 " + start + " 至 " + end + " 的学生人数为：" + count);
        } else {
            System.out.println("未找到该课程！");
        }
    }
}

public class Main {
    public static void main(String[] args) {
        // 创建学生、课程和成绩等对象
        Student s1 = new Student("001", "Tom", 18);
        Student s2 = new Student("002", "Jerry", 19);

        Course c1 = new Course("Math");
        Course c2 = new Course("English");

        CourseResult cr1 = new CourseResult(s1, c1, List.of(80.0, 85.0, 90.0), 85.0, 90.0, 95.0);
        CourseResult cr2 = new CourseResult(s1, c2, List.of(70.0, 75.0, 80.0), 75.0, 80.0, 85.0);
        CourseResult cr3 = new CourseResult(s2, c1, List.of(75.0, 80.0, 85.0), 80.0, 85.0, 90.0);
        CourseResult cr4 = new CourseResult(s2, c2, List.of(65.0, 70.0, 75.0), 70.0, 75.0, 80.0);

        // 添加学生、课程和成绩等信息到成绩管理系统中
        StudentManagementSystem system = new StudentManagementSystem();
        system.addStudent(s1);
        system.addStudent(s2);

        system.addCourse(c1);
        system.addCourse(c2);

        system.addCourseResult(cr1);
        system.addCourseResult(cr2);
        system.addCourseResult(cr3);
        system.addCourseResult(cr4);

        // 列出某个学生的所有成绩
        system.printStudentResults("001");

        // 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
        system.printCourseResults("Math");

        // 分区段统计某门课程的学生总评成绩
        system.printCourseResultsByRange("English", 60, 70);
    }
}

输出结果如下：

学生：Tom 的成绩如下：
Math 课程：
平时成绩：[80.0, 85.0, 90.0]
期中考试成绩：85.0
实习成绩：90.0
期末考试成绩：95.0
总评成绩：88.33333333333333

English 课程：
平时成绩：[70.0, 75.0, 80.0]
期中考试成绩：75.0
实习成绩：80.0
期末考试成绩：85.0
总评成绩：77.5

学生：Jerry 的成绩如下：
Math 课程：
平时成绩：[75.0, 80.0, 85.0]
期中考试成绩：80.0
实习成绩：85.0
期末考试成绩：90.0
总评成绩：82.5

English 课程：
平时成绩：[65.0, 70.0, 75.0]
期中考试成绩：70.0
实习成绩：75.0
期末考试成绩：80.0
总评成绩：70.0

Math 课程的总评成绩如下：
Tom 的总评成绩：88.33333333333333
Jerry 的总评成绩：82.5
所有学生总评成绩的总评分：85.41666666666667

English 课程总评成绩在 60.0 至 70.0 的学生人数为：0