用java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Java代码实现学生成绩管理系统的基本功能：

import java.util.ArrayList;

class Student {
    private String id;
    private String name;
    private int age;
    private ArrayList<Course> courses;

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

    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public void addCourse(Course course) {
        courses.add(course);
    }

    public ArrayList<Course> getCourses() {
        return courses;
    }
}

class Course {
    private String name;
    private ArrayList<Double> dailyGrades;
    private double midGrade;
    private double pracGrade;
    private double finalGrade;
    private double totalGrade;

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

    public String getName() {
        return name;
    }

    public void addDailyGrade(double grade) {
        dailyGrades.add(grade);
    }

    public void setMidGrade(double grade) {
        this.midGrade = grade;
    }

    public void setPracGrade(double grade) {
        this.pracGrade = grade;
    }

    public void setFinalGrade(double grade) {
        this.finalGrade = grade;
    }

    public double getTotalGrade() {
        return totalGrade;
    }

    public void calculateTotalGrade() {
        double dailyGradeSum = 0;
        for (double grade : dailyGrades) {
            dailyGradeSum += grade;
        }
        double dailyGradeAvg = dailyGradeSum / dailyGrades.size();
        totalGrade = (dailyGradeAvg + midGrade + pracGrade + finalGrade) / 4;
    }
}

public class GradeManagementSystem {
    private ArrayList<Student> students;

    public GradeManagementSystem() {
        this.students = new ArrayList<>();
    }

    public void addStudent(Student student) {
        students.add(student);
    }

    public void listStudentGrades(String studentId) {
        for (Student student : students) {
            if (student.getId().equals(studentId)) {
                System.out.println("Student ID: " + student.getId());
                System.out.println("Student Name: " + student.getName());
                for (Course course : student.getCourses()) {
                    System.out.println("Course Name: " + course.getName());
                    System.out.println("Daily Grades: " + course.getDailyGrades().toString());
                    System.out.println("Midterm Grade: " + course.getMidGrade());
                    System.out.println("Practice Grade: " + course.getPracGrade());
                    System.out.println("Final Exam Grade: " + course.getFinalGrade());
                    System.out.println("Total Grade: " + course.getTotalGrade());
                }
            }
        }
    }

    public void listCourseGrades(String courseName) {
        double totalGradeSum = 0;
        int totalGradeCount = 0;
        for (Student student : students) {
            for (Course course : student.getCourses()) {
                if (course.getName().equals(courseName)) {
                    System.out.println("Student Name: " + student.getName());
                    System.out.println("Total Grade: " + course.getTotalGrade());
                    totalGradeSum += course.getTotalGrade();
                    totalGradeCount++;
                }
            }
        }
        double totalGradeAvg = totalGradeSum / totalGradeCount;
        System.out.println("Total Grade Average: " + totalGradeAvg);
    }

    public void listCourseGradeDistribution(String courseName) {
        int[] gradeCounts = new int[11];
        for (Student student : students) {
            for (Course course : student.getCourses()) {
                if (course.getName().equals(courseName)) {
                    int grade = (int) Math.floor(course.getTotalGrade() / 10);
                    if (grade < 0) {
                        grade = 0;
                    }
                    if (grade > 10) {
                        grade = 10;
                    }
                    gradeCounts[grade]++;
                }
            }
        }
        for (int i = 0; i < 10; i++) {
            System.out.println(i * 10 + " - " + (i + 1) * 10 + " Count: " + gradeCounts[i]);
        }
        System.out.println("100 Count: " + gradeCounts[10]);
    }

    public static void main(String[] args) {
        GradeManagementSystem system = new GradeManagementSystem();

        // Add some students and courses
        Student student1 = new Student("101", "Alice", 20);
        Course course1 = new Course("Math");
        course1.addDailyGrade(80);
        course1.addDailyGrade(90);
        course1.setMidGrade(75);
        course1.setPracGrade(85);
        course1.setFinalGrade(90);
        course1.calculateTotalGrade();
        student1.addCourse(course1);
        system.addStudent(student1);

        Student student2 = new Student("102", "Bob", 21);
        Course course2 = new Course("English");
        course2.addDailyGrade(85);
        course2.addDailyGrade(95);
        course2.addDailyGrade(90);
        course2.setMidGrade(80);
        course2.setPracGrade(90);
        course2.setFinalGrade(85);
        course2.calculateTotalGrade();
        student2.addCourse(course2);
        system.addStudent(student2);

        // Test the system functions
        system.listStudentGrades("101");
        system.listCourseGrades("Math");
        system.listCourseGradeDistribution("Math");
    }
}

在上面的代码中，我们定义了两个类：Student 和 Course。Student 类表示学生，包含学号、姓名、年龄等属性和一个课程列表。Course 类表示课程，包含课程名、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。我们还定义了一个 GradeManagementSystem 类表示成绩管理系统，包括添加学生、列出某个学生的所有成绩、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、分区段统计某门课程的学生总评成绩等功能。

在 main 函数中，我们创建了两个学生和两个课程，并测试了系统的功能。你可以根据需要修改代码以适应你的需求。