Redis使用场景总结

public class LeaderboardService {
    private final RedisTemplate<String, String> redisTemplate;

    public LeaderboardService(RedisTemplate<String, String> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    // 添加玩家到排行榜
    public void addPlayerToLeaderboard(String player, double score) {
        redisTemplate.opsForZSet().add("leaderboard", player, score);
    }

    // 获取排行榜中前 N 名玩家 /rɪˈvɜːs/
    public Set<ZSetOperations.TypedTuple<String>> getLeaderboard(int topN) {
        return redisTemplate.opsForZSet().reverseRangeWithScores("leaderboard", 0, topN - 1);
    }

    // 更新玩家在排行榜中的分数
    public void updatePlayerScore(String player, double score) {
        redisTemplate.opsForZSet().incrementScore("leaderboard", player, score);
    }

    // 从排行榜中移除玩家
    public void removePlayerFromLeaderboard(String player) {
        redisTemplate.opsForZSet().remove("leaderboard", player);
    }
}

/**
 * 一等奖1个,二等奖2个,三等奖3个,参与奖100个
 */
public class LotteryService {
    private final RedisTemplate<String, String> redisTemplate;
    private final JdbcTemplate jdbcTemplate;
    private static final String SPOP_USER_SETS = "pop:user:set";

    public LotteryService(JdbcTemplate jdbcTemplate, RedisTemplate<String, String> redisTemplate) {
        this.jdbcTemplate = jdbcTemplate;
        this.redisTemplate = redisTemplate;
    }

    public void initUserSet(String prize) {
        String sql = "select id from user";
        List<Map<String, Object>> userIds = jdbcTemplate.queryForList(sql);
        SetOperations<String, String> ops = redisTemplate.opsForSet();
        String[] ids = userIds.stream().map(item -> String.valueOf(item.get("id").toString())).toArray(String[]::new);
        ops.add(SPOP_USER_SETS, ids);
    }

    public void drawAllPrize() {
        List<String> firstPrize = drawPrize(1);
        System.out.println("一等奖:" + firstPrize.get(0));
        List<String> secondPrize = drawPrize(2);
        System.out.println("二等奖:" + String.join(",", secondPrize));
        List<String> thirdPrize = drawPrize(3);
        System.out.println("三等奖:" + String.join(",", thirdPrize));
        List<String> participationPrize = drawPrize(100);
        System.out.println("参与奖:" + String.join(",", participationPrize));
    }

    /**
     * 一个人最多获取一次奖品
     * @param count
     * @return
     */
    public List<String> drawPrize(int count) {
        SetOperations<String, String> ops = redisTemplate.opsForSet();
        // Remove and return count random members from set at key.
        return ops.pop("prize_pool", count);
    }

    /**
     * draw 抽取
     * 允许一个人多次抽取奖品
     * @param count
     * @return
     */
    public List<String> drawPrize4duplicate(int count) {
        SetOperations<String, String> ops = redisTemplate.opsForSet();
        // Get count random elements from set at key.
        return ops.randomMembers("prize_pool", count);
    }

}

public class Stats4String {
    private RedisTemplate<String, String> redisTemplate;

    public Stats4String(RedisTemplate<String, String> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    // 比如点赞/收藏
    public void incrementCount(String key) {
        ValueOperations<String, String> ops = redisTemplate.opsForValue();
        ops.increment(key);
    }

    // 比如取消点赞/取消收藏
    public void decrementCount(String key) {
        ValueOperations<String, String> ops = redisTemplate.opsForValue();
        ops.decrement(key);
    }

    // 获取统计数量
    public Long getCount(String key) {
        ValueOperations<String, String> ops = redisTemplate.opsForValue();
        String countStr = ops.get(key);

        if (countStr != null) {
            return Long.parseLong(countStr);
        } else {
            return 0L;
        }
    }

    // 清空统计数据
    public void clearCount(String key) {
        redisTemplate.delete(key);
    }
}

public class Stats4HyperLogLog {
    private RedisTemplate<String, String> redisTemplate;

    public Stats4HyperLogLog(RedisTemplate<String, String> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    // 添加元素到 HyperLogLog
    public void addElement(String key, String... elements) {
        HyperLogLogOperations<String, String> ops = redisTemplate.opsForHyperLogLog();
        ops.add(key, elements);
    }

    // 获取 HyperLogLog 的基数估计值
    public long getApproximateCount(String key) {
        HyperLogLogOperations<String, String> ops = redisTemplate.opsForHyperLogLog();
        return ops.size(key);
    }

    // 合并多个 HyperLogLog
    public void mergeHyperLogLogs(String destinationKey, String... sourceKeys) {
        HyperLogLogOperations<String, String> ops = redisTemplate.opsForHyperLogLog();
        ops.union(destinationKey, sourceKeys);
    }

    // 清空 HyperLogLog
    public void clearHyperLogLog(String key) {
        redisTemplate.delete(key);
    }
}

public class SetStats4Set {
    private final RedisTemplate<String, String> redisTemplate;

    public SetStats4Set(RedisTemplate<String, String> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    // 例如点赞
    public void add(String key, String... elements) {
        SetOperations<String, String> ops = redisTemplate.opsForSet();
        ops.add(key, elements);
    }

    // 例如取消点赞
    public void remove(String key, Object... elements) {
        SetOperations<String, String> ops = redisTemplate.opsForSet();
        ops.remove(key, elements);
    }

    // 例如点赞数
    public long getDistinctCount(String key) {
        SetOperations<String, String> ops = redisTemplate.opsForSet();
        Long size = ops.size(key);
        return size != null ? size : 0L;
    }

    // 例如点赞的人
    public Set<String> members(String key) {
        SetOperations<String, String> ops = redisTemplate.opsForSet();
        return ops.members(key);
    }

    // 清空集合
    public void clearSet(String key) {
        redisTemplate.delete(key);
    }
}

@Component
public class BitmapStatsService {
    @Autowired
    private RedisTemplate<String, String> redisTemplate;


    // 例如点赞
    public void add(String key, int userId) {
        setBit(key, userId, true);
    }

    // 例如取消点赞
    public void remove(String key, int userId) {
        setBit(key, userId, false);
    }

    // 例如点赞数
    public long getDistinctCount(String key) {
        return bitCount(key);
    }

    // 例如点赞的人
    public List<Integer> members(String key) {
        String value = redisTemplate.opsForValue().get(key);
        List<Integer> list = new ArrayList<>();
        for (byte b : value.getBytes()) {
            for (int i = 7; i >= 0; i--) {
                list.add((b >> i) & 1);
            }
        }
        List<Integer> result = new ArrayList<>();
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i) == 1) {
                result.add(i);
            }
        }
        return result;
    }


    // 设置指定位置的位值
    public void setBit(String key, long offset, boolean value) {
        redisTemplate.opsForValue().setBit(key, offset, value);
    }

    // 获取指定位置的位值
    public Boolean getBit(String key, long offset) {
        return redisTemplate.opsForValue().getBit(key, offset);
    }

    // 统计指定范围内的位值为 true 的个数
    public Long bitCount(String key) {
        return redisTemplate.execute((RedisCallback<Long>) connection -> connection.bitCount(key.getBytes()));
    }

    public Long bitCount(String key, long start, long end) {
        return redisTemplate.execute((RedisCallback<Long>) connection -> connection.bitCount(key.getBytes(), start, end));
    }

    // 首签时间
    public Long bitPos(String key, boolean bit) {
        return redisTemplate.execute((RedisCallback<Long>) connection -> connection.bitPos(key.getBytes(), bit));
    }

    public Long bitPos(String key, boolean bit, Long start, Long end) {
        Range<Long> range = Range.closed(start, end);
        return redisTemplate.execute((RedisCallback<Long>) connection -> connection.bitPos(key.getBytes(), bit, range));
    }

    // 连续签到/累计签到
    public Long bitOp(RedisStringCommands.BitOperation op, String destination, String... keys) {
        byte[][] keyBytes = new byte[keys.length][];
        for (int i = 0; i < keys.length; i++) {
            keyBytes[i] = keys[i].getBytes();
        }
        return redisTemplate.execute((RedisCallback<Long>) connection -> connection.bitOp(op, destination.getBytes(), keyBytes));
    }
}