Redis 大key的几种删除方式

String key = "demo";
int length = jedis.llen("demo");
if (length > 1024) {
    int size = 100;
    int count = 0;
    do {
        //每次处理前100个
        // redis内部也会判断当前传递的索引有没有超过当前的list的长度
        // 可参阅 ltrimCommand
        jedis.ltrim(key, 0, size);
        count += size;
    }
        while (count < length);
}
jedis.del(key);

String key = "demo";

long length = jedis.scard(key);
if (length > 1024) {
    //每次遍历100个
    ScanParams scanParams = new ScanParams().count(100);
    // 传递的游标
    java.lang.String cursor = "0";
    ScanResult<String> sscan;
    do {
        //传递 scan的参数
        sscan = jedis.sscan(key, cursor, scanParams);
        if (!CollectionUtils.isEmpty(sscan.getResult())) {
            // 遍历返回的结果，依次删除
            sscan.getResult().stream().forEach(member -> {
                jedis.srem(key, member);
            });
        }
        // 传入下次遍历的游标
        cursor = sscan.getCursor();
    } while (!sscan.isCompleteIteration());
}
jedis.del(key);

String key = "demo";
// 获取zset的长度
long length = jedis.zcard(key);
if (length > 1024) {
    int size = SIZE;
    int count = 0;
    do {
        // 删除指定的集合
        jedis.zremrangeByRank(key, 0, size);
        count += size;
    }
    while (count < length);
}
jedis.del(key);

String key = "demo";
// 获取Hash的字段个数
long length = jedis.hlen(key);
if (length > THROLD) {
    ScanParams scanParams = new ScanParams();
    // 遍历大小
    scanParams.count(SIZE);
    // 匹配哪些字段
    scanParams.match("*");
    ScanResult<Map.Entry<String, String>> result;
    java.lang.String cursor = "0";
    do {
        // 遍历字段
        result = jedis.hscan(key, cursor, scanParams);
        if (!CollectionUtils.isEmpty(result.getResult())) {
            // 删除指定的字段
            result.getResult().stream().forEach(x -> {
                jedis.hdel(key, x.getKey());
            });
        }
        cursor = result.getCursor();
    } while (!result.isCompleteIteration());
}
jedis.del(key);