Java开发社区积分系统实战详解

public class User {
    private Long id;
    private String username;
    private Integer points; // 当前总积分
    // getter/setter
}

public class Question {
    private Long id;
    private String title;
    private String content;
    private Long userId;
    private Boolean isAdopted;
    // getter/setter
}

public class Answer {
    private Long id;
    private String content;
    private Long questionId;
    private Long userId;
    private Boolean isAccepted;
    // getter/setter
}

public class PointRecord {
    private Long id;
    private Long userId;
    private Integer change; // 积分变化值，正为加，负为减
    private String reason;  // 如“回答问题”、“被采纳”
    private Date createTime;
    // getter/setter
}

public class PointService {

    public void awardPoints(Long userId, int points, String reason) {
        // 更新用户总积分
        userDao.updatePoints(userId, points);
        // 记录积分明细
        PointRecord record = new PointRecord();
        record.setUserId(userId);
        record.setChange(points);
        record.setReason(reason);
        record.setCreateTime(new Date());
        pointRecordDao.save(record);
    }

    // 回答问题加分
    public void onAnswerSubmitted(Long userId) {
        awardPoints(userId, 10, "回答问题");
    }

    // 回答被采纳
    public void onAnswerAccepted(Long userId) {
        awardPoints(userId, 20, "回答被采纳");
    }

    // 提问加分
    public void onQuestionPosted(Long userId) {
        awardPoints(userId, 5, "提出问题");
    }

    // 被点赞
    public void onLiked(Long userId) {
        awardPoints(userId, 2, "内容被点赞");
    }

    // 被踩扣分
    public void onDisliked(Long userId) {
        awardPoints(userId, -1, "内容被踩");
    }
}

@Transactional
public void awardPoints(Long userId, int points, String reason) {
    userDao.updatePoints(userId, points);  // UPDATE user SET points = points + ? WHERE id = ?
    pointRecordDao.save(buildRecord(userId, points, reason));
}