Redis-多字段排序-排名设计

Redis的sorted set集合提供了一种有序的集合，集合中的每个元素都会关联一个double类型的分数。redis正是通过分数来为集合中的成员进行从小到大的排序。
使用场景通常是作为排名。
在上一篇说了选择题型题目表设计，接着这篇说下用户回答题目后的排行设计，这里使用redis的有序集合进行排名，排名条件是正确率高，耗时少。

有序集合添加元素时需设定一个分数，这里两个排序条件不同，一个按照正确率倒序，一个按照耗时升序，所以需要设计一个分数计算算法。

这里通过位运算进行计算分数，将正确率*100后左移32位，再用Integer.MAX_VALUE-耗时(毫秒)，将两者结果进行或运算，这样，正确率越高，耗时越少，分数越高，再反向排名即可。

demo使用springboot框架
redis客户端使用redisson；
orm使用mybatis

model

package com.example.demo.model;

import lombok.Data;

import java.util.Date;

@Data
public class Question {
    private Long id;

    private String title;

    private Date createAt;

    private Long createBy;

    private Integer status;

    private Date updateAt;

    private Long updateBy;

}

package com.example.demo.model;

import lombok.Data;

import java.util.Date;

@Data
public class QuestionAnswer {
    private Long id;

    private Long userId;

    private Long questionId;

    private Long optionId;

    private Long historyId;

    private Integer status;

    private Date updateAt;

    private Long updateBy;

    private Date createAt;

    private Long createBy;

}

package com.example.demo.model;

import lombok.Data;

import java.io.Serializable;
import java.util.Date;

@Data
public class QuestionAnswerHistory implements Serializable {
    private Long id;

    private Long userId;

    private Boolean answerFinish;

    private Double correctRate;

    private Integer timeConsumed;

    private Integer status;

    private Date createAt;

    private Long createBy;

    private Integer createAtMillisecond;

    private Date updateAt;

    private Long updateBy;

    private Integer updateAtMillisecond;

    private Integer timeConsumedMillisecond;

}

package com.example.demo.model;

import lombok.Data;

import java.util.Date;

@Data
public class QuestionOption {
    private Long id;

    private Long questionId;

    private String content;

    private Boolean isAnswer;

    private Integer status;

    private Date createAt;

    private Long createBy;

    private Date updateAt;

    private Long updateBy;

}

mapper

package com.example.demo.mapper;

import com.example.demo.model.QuestionAnswerHistory;
import com.example.demo.model.QuestionAnswerHistoryExample;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.ResultMap;
import org.apache.ibatis.annotations.Select;

import java.util.List;

public interface QuestionAnswerHistoryMapper {
    @Select("select t.id,t.user_id,t.correct_rate,t.time_consumed,t.time_consumed_millisecond from (" +
            "select id,user_id,correct_rate,time_consumed,time_consumed_millisecond from question_answer_history where answer_finish = true and status = #{status}  " +
            " order by correct_rate desc, time_consumed asc,time_consumed_millisecond asc limit 100000 ) t group by t.user_id " +
            " order by correct_rate desc, time_consumed asc,time_consumed_millisecond asc")
    @ResultMap("BaseResultMap")
    List queryTop(@Param("status") int status);
}

QuestionAnswerHistoryService

package com.example.demo.service;

import com.example.demo.common.Constant;
import com.example.demo.mapper.QuestionAnswerHistoryMapper;
import com.example.demo.model.QuestionAnswerHistory;
import org.apache.commons.lang3.RandomUtils;
import org.redisson.api.RScoredSortedSet;
import org.redisson.api.RedissonClient;
import org.redisson.client.protocol.ScoredEntry;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.math.BigDecimal;
import java.util.*;

/**
 * @author wzx
 * @time 2019/6/16
 */
@Service
public class QuestionAnswerHistoryService {

    @Autowired
    private QuestionAnswerHistoryMapper historyMapper;

    @Autowired
    private RedissonClient client;

    private static final String QUESTION_TOP_KEY = "QUESTION_TOP_KEY";

    private RScoredSortedSet