Redis 使用Scan迭代keys

使用需求: 对大批量keys进行操作会阻塞Redis,导致Redis无法正常提供服务,所以一般使用Scan迭代进行批量操作,而不是一次性进行操作

常用使用场景: 批量删除keys, 对符合某些规则的key迭代进行批量操作

@org.junit.Test
    public void scanSM() {
        Jedis jedis = null;
        try {
            jedis = new Jedis("192.168.15.151", 6379);
            for (int i = 0; i < 100; i++) {
                jedis.set("key" + i, i + "");
            }
            for (int i = 0; i < 100; i++) {
                jedis.set("aaa" + i, i + "");
            }
            List list = getScan(jedis, "key*");
            System.out.println("长度:"+list.size()+"  \nlist:"+list);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (null != jedis) {
                jedis.close();
            }
        }
    }

    public static List getScan(Jedis jedis, String key) {
        List list   = new ArrayList<>();
        ScanParams   params = new ScanParams();
        params.match(key);
        params.count(2);
        String cursor = "0";
        while (true) {
            ScanResult   scanResult = jedis.scan(cursor, params);
            List elements   = scanResult.getResult();
            if (elements != null && elements.size() > 0) {
                list.addAll(elements);
            }
            cursor = scanResult.getStringCursor();
            System.out.println("cursor: "+cursor);
            if ("0".equals(cursor)) {
                break;
            }
        }
        return list;
    }