使用nginx+lua脚本读写redis缓存

配置

新建spring boot项目增加redis配置

        <dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-redis</artifactId>
		</dependency>

在需要缓存的地方增加redis缓存

package com.example.sharding.service;

import com.alibaba.fastjson.JSON;
import com.example.sharding.entity.Order;
import com.example.sharding.mapper.OrderMapper;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.io.IOException;
import java.util.List;

@Service
@Transactional
public class OrderService {

    @Autowired
    private OrderMapper orderMapper;

    @Autowired
    private RedisTemplate redisTemplate;

    public Object findAll() throws IOException {
        List<Order> orders = orderMapper.selectAll();
        ObjectMapper mapper = new ObjectMapper();
        redisTemplate.opsForValue().set("orders",mapper.writeValueAsString(orders));
        return orders;
    }

    public void save(Order order) {
        orderMapper.insert(order);
        redisTemplate.opsForHash().put("order",order.getOrderId().toString(), JSON.parseObject(JSON.toJSONString(order)).toJSONString());
    }

    public void deleteAll() {
        orderMapper.deleteAll();
        redisTemplate.delete("order");
        redisTemplate.delete("orders");
    }
}

修改example.conf

server {
    listen       80;
    server_name  _;  

    location = /order {
	    default_type 'text/html';
	    lua_code_cache off;
	    content_by_lua_file C:\work\openresty-1.13.6.1-win32\example\lua/test_redis_basic.lua;
	}

    location /lua {
        default_type 'text/html';
        lua_code_cache off;
        content_by_lua_file C:\work\openresty-1.13.6.1-win32\example\lua/test.lua;
    }

    # 其他请求回源到tomcat
    location / {
    	proxy_pass http://tomcat/;
	}  

}

# 后端服务地址
upstream tomcat {
    server 127.0.0.1:8080 max_fails=5 fail_timeout=10s weight=1;
    keepalive 100;
}  

修改test_redis_basic.lua文件

local function close_redis(red)
    if not red then
        return
    end
    local ok, err = red:close()
    if not ok then
        ngx.say("close redis error : ", err)
    end
end  

local function read_order()
    local resp = ngx.location.capture("/order/query", {
        method = ngx.HTTP_GET
    })
    if not resp then
        return
    end
    if resp.status ~= 200 then
        return
    end
    return resp.body
end  

local redis = require("resty.redis")
local cjson = require("cjson")  -- 引入json模块

--创建实例
local red = redis:new()
--设置超时（毫秒）
red:set_timeout(1000)
--建立连接
local ip = "127.0.0.1"
local port = 6379
local ok, err = red:connect(ip, port)
if not ok then
    ngx.say("connect to redis error : ", err)
    return close_redis(red)
end 

local res, err = red:auth("shiyuesoft")
if not res then
    ngx.say("failed to authenticate: ", err)
    return
end

--调用API获取数据
local resp, err = red:get("orders")
if not resp then
    ngx.say("get msg error : ", err)
    return close_redis(red)
end
--得到的数据为空处理
if resp == ngx.null then
    resp = read_order()  --回源到tomcat去查询
end
ngx.say(cjson.decode(resp))  --对返回的数据转换成json对象

close_redis(red)  

先请求deleteAll删除所有缓存

新增order数据

访问/order地址

第一次由于没有缓存，会进入接口查询

后面继续刷新页面，不会再进入后端接口了