Develop knowledge points

 //TODO 5、 Anti duplication token ( Prevent forms from being submitted repeatedly )
        // Set a for the user token, Thirty minute expiration time （ There is redis）
        String token = UUID.randomUUID().toString().replace("-", "");
        redisTemplate.opsForValue().set(USER_ORDER_TOKEN_PREFIX+memberResponseVo.getId(),token,30, TimeUnit.MINUTES);
        confirmVo.setOrderToken(token);

Generate uuid As redis Of key

redis The script determines whether the data passed from the front end is consistent with the back end

  //1、 Verify that the token is legal 【 The comparison and deletion of tokens must ensure atomicity 】
        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
        String orderToken = vo.getOrderToken();

        // adopt lure Script atomic authentication token and delete token 
        Long result = redisTemplate.execute(new DefaultRedisScript<Long>(script, Long.class),
                Arrays.asList(USER_ORDER_TOKEN_PREFIX + memberResponseVo.getId()),
                orderToken);

Set to string

 // Use StringUtils.collectionToDelimitedString take list Set to String
        String skuAttrValues = StringUtils.collectionToDelimitedString(items.getSkuAttrValues(), ";");