Java는 온라인 시험 시스템에서 시험지 점수 통계 및 분석을 구현합니다.

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;
    }
}