java计算每个同学的平均成绩，分为Student,average,entrance类

在Java中，我们可以创建三个相关的类来处理这个需求：`Student`, `AverageCalculator`, 和 `Entrance` 类。下面是一个简化的例子：

1. **Student** 类：代表一个学生，包含个人信息和成绩属性。

public class Student {
    private String name;
    private double[] scores;

    public Student(String name, double[] scores) {
        this.name = name;
        this.scores = scores;
    }

    // getters and setters for name and scores
    public String getName() {
        return name;
    }
    
    public void setName(String name) {
        this.name = name;
    }

    public double[] getScores() {
        return scores;
    }
    
    // 如果需要，可以添加getAverageScore()方法来获取当前学生的平均成绩
}

2. **AverageCalculator** 类：用于计算所有学生或特定学生群体的平均成绩。

public class AverageCalculator {
    private List<Student> students;

    public AverageCalculator(List<Student> students) {
        this.students = students;
    }

    public double calculateAverage(Student student) {
        if (student.getScores().length == 0) {
            throw new IllegalArgumentException("No scores found for the student.");
        }
        double sum = 0;
        for (double score : student.getScores()) {
            sum += score;
        }
        return sum / student.getScores().length;
    }
    
    // 添加一个方法来计算整个学生列表的平均分
    public double calculateOverallAverage() {
        double totalSum = 0;
        for (Student student : students) {
            totalSum += calculateAverage(student);
        }
        return totalSum / students.size();
    }
}

3. **Entrance** 类（如果这是入学管理系统的类）：可能包含初始化学生列表或操作平均成绩的方法。

public class Entrance {
    private AverageCalculator calculator;

    public Entrance(List<Student> students) {
        this.calculator = new AverageCalculator(students);
    }

    public void enroll(Student student) {
        // 添加新学生到列表
    }

    public void displayAverage(Student targetStudent) {
        double average = calculator.calculateAverage(targetStudent);
        System.out.println("The average score of " + targetStudent.getName() + " is " + average);
    }

    // 其他入口点如显示总体平均分
    public void displayOverallAverage() {
        double overallAverage = calculator.calculateOverallAverage();
        System.out.println("Overall average score is " + overallAverage);
    }
}