Java はオンライン試験システムに試験用紙のスコアの統計と分析を実装します

public class ExamResult {
    private String studentId;
    private String examId;
    private double score;
    private Date examDate;

    // 构造函数
    public ExamResult(String studentId, String examId, double score, Date examDate) {
        this.studentId = studentId;
        this.examId = examId;
        this.score = score;
        this.examDate = examDate;
    }

    // getter和setter方法

    public String getStudentId() {
        return studentId;
    }

    public void setStudentId(String studentId) {
        this.studentId = studentId;
    }

    public String getExamId() {
        return examId;
    }

    public void setExamId(String examId) {
        this.examId = examId;
    }

    public double getScore() {
        return score;
    }

    public void setScore(double score) {
        this.score = score;
    }

    public Date getExamDate() {
        return examDate;
    }

    public void setExamDate(Date examDate) {
        this.examDate = examDate;
    }
}

import java.sql.*;

public class ExamResultDAO {
    private Connection connection;

    public ExamResultDAO() {
        // 连接数据库的代码
        // ...
    }

    // 存储试卷成绩的方法
    public void saveExamResult(ExamResult examResult) {
        // 执行SQL语句将试卷成绩存储到数据库中
        // ...
    }

    // 根据学生ID和试卷ID查询试卷成绩的方法
    public ExamResult getExamResult(String studentId, String examId) {
        // 执行SQL语句查询试卷成绩
        // ...
        return examResult;
    }

    // 其他数据统计和分析方法
    // ...
}

public class ExamAnalysis {
    // 统计学生在某个考试中的平均分
    public double averageScore(String examId) {
        // 查询所有参加该考试的学生成绩
        List<ExamResult> results = examResultDAO.getExamResultsByExamId(examId);
        
        // 计算平均分
        double totalScore = 0;
        for (ExamResult result : results) {
            totalScore += result.getScore();
        }
        return totalScore / results.size();
    }

    // 统计某个学生的所有考试成绩的平均分
    public double averageScoreByStudent(String studentId) {
        // 查询该学生的所有考试成绩
        List<ExamResult> results = examResultDAO.getExamResultsByStudentId(studentId);
        
        // 计算平均分
        double totalScore = 0;
        for (ExamResult result : results) {
            totalScore += result.getScore();
        }
        return totalScore / results.size();
    }

    // 根据考试日期统计该日期内的考试成绩
    public List<ExamResult> getExamResultsByDate(Date startDate, Date endDate) {
        // 查询在指定日期范围内的所有考试成绩
        List<ExamResult> results = examResultDAO.getExamResultsByDate(startDate, endDate);
        
        return results;
    }
}