利用redis+lua优雅实现每天给用户发短信次数限制

最近的一个需求要求实现每天给用户发短信不超过3次，并且发短信间隔不能小于1小时，思来想去有没有什么比较好的实现方式呢，最终决定用redis+lua来实现，第一次写lua脚本。还不太熟练，不过完美的把功能实现了，废话不多说，上代码

1.controller层的调用

package com.example.lua.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.scripting.support.ResourceScriptSource;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.time.LocalDateTime;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;


@RestController
public class Test1Controller {
    @Autowired
    private StringRedisTemplate redisTemplate;
 
    @RequestMapping("test1")
    public void test() {
        System.out.println("xxxxxxxxxxxxxx");
            //调用lua脚本并执行
            DefaultRedisScript redisScript = new DefaultRedisScript<>();
            redisScript.setResultType(Boolean.class);//返回类型是Long
            redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("redis/clear-local-key1.lua")));

            LocalDateTime now = LocalDateTime.now();
            int dayOfYear = now.getDayOfYear();
            int minute = now.getMinute();
            int hour = now.getHour();

            String userId = "123";
            //默认value
            String limitValue = "1."+(hour * 60 + minute);
            //当晚23:59:59秒过期
            int expireTime = (24*60 - (hour * 60 + minute))*60;
            Boolean ans = redisTemplate.execute(redisScript, Arrays.asList("sms_limit_key:"+userId+":"+dayOfYear), limitValue,String.valueOf(expireTime));
            if(ans) {
                System.out.println("发短信给用户");
            }
    }
}

2.lua脚本的编写

local sms_send_key = KEYS[1];
local sms_send_value = ARGV[1];
local expire_time = ARGV[2];
--解析string字符串 分解出.前缀和.后缀(str = '1.234'  prefix = 1 suffix = 234)
local function parse(str)
    local start_index ,end_index = string.find(str,".",1)
    local prefix = string.sub(str,1,start_index)
    local suffix = string.sub(str,start_index+2,-1)
    return prefix,suffix
end

local value  = redis.call("setnx",sms_send_key,sms_send_value)
--设置成功 说明之前不存在
if(value == 1)
      then   redis.call("expire",sms_send_key,expire_time)
      return true;
else
      local oldValue = tostring(redis.call("get",sms_send_key))
      local oldPre,oldSuf = parse(oldValue)
      local newPre,newSuf = parse(sms_send_value)
--超过60分钟可以发送
        if tonumber(oldPre) <=2 and (tonumber(newSuf) - tonumber(oldSuf)) >= 60
            then
            local newValue = tostring(-0)..'.'..tostring(oldSuf)
            redis.call("incrbyfloat",sms_send_key,sms_send_value)
            redis.call("incrbyfloat",sms_send_key,tonumber(newValue))
            return true;
        else
            return false;
        end
end

好了，结束