redis 作缓存

男娘i 2022-12-10 14:56 128阅读 0赞

# 需求 #

天气接口，调用限制4000次每天，用户请求次数过多会造成次数上限，使用redis缓存过滤请求

# 实现思路 #

用户调用----查redis中是否有该城市天气数据存在，若不存在，调用接口并存到redis里面，有效期2小时，若存在2小时的天气信息，返回

# redis ubuntu安装启动 #

wget http://download.redis.io/releases/redis-2.8.9.tar.gz
    	
    	tar xvfz redis-2.8.9.tar.gz
    	
    	cd redis-2.8.9
    	
    	sudo make	
    	
    	sudo make install
    	
    	sudo make test
    	
    	
    	启动 脚本文件
    	nohup  comman  &  后台启动，关闭终端不关闭
    	
    	nohup src/redis-server redis.conf &

# 实现代码： #

@Autowired
        JedisPool jedisPool;
        
        。。。。。
        
    public String getWeather(String schoolId) {
    
            Jedis redis = jedisPool.getResource();
    
            if (StringUtils.isEmpty(schoolId)) {
                //未传机构id，是定时器查询，调用接口来查询并存入到数据库中
            } else {
                School school = this.selectSchoolById(schoolId);
                String address = school.getXz().split(",")[1];
                //传机构id，是人为发起天气调用，查询缓存中是否有该城市的天气信息
                String res = RedisUtil.find("weather" + address, redis);
    
                if (StringUtils.isNotEmpty(res)) {
                    //缓存中有该城市天气数据，不再调用接口
                    return res;
                } else {
                    //未查询到天气数据，调用接口查询
                    Object queryRes = getApiWeather(address);
    
                    if (GukeerStringUtil.isNullOrEmpty(queryRes))
                        return null;
    
                    String key = "weather" + address;
                    try {
                        RedisUtil.add(key, queryRes.toString(), redis);
                        RedisUtil.setExpire(key, 60*120, redis);
                        RedisUtil.returnResource(redis);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
    
                    return queryRes.toString();
                }
            }
            return null;
        }
        
        
        public static Object getApiWeather(String city) {
            Properties pro = PropertiesUtil.getProperties("db.properties");
            String key = pro.getProperty("weather.key");
            String url = pro.getProperty("weather.url");
    
            Map param = new HashMap();
            param.put("city", city);
            param.put("key", key);
    
            String res = null;
            try {
                res = HttpRequestUtil.post(url, null, null, param);
            } catch (IOException e) {
                e.printStackTrace();
            }
    
            if (StringUtils.isEmpty(res))
                return null;
    
            JSONObject object = JSONObject.fromObject(res);
            JSONArray array = JSONArray.fromObject(object.get("HeWeather5").toString());
    
            if (array.length() > 0)
                return array.get(0);
            else
                return null;
        }
        
        
        redis配置：
        
        
        
        <?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
    
        
    
        
        <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
            <property name="maxTotal" value="${redis.maxActive}"/>
            <property name="maxIdle" value="${redis.maxIdle}"/>
            <property name="minIdle" value="${redis.minIdle}"/>
            <property name="testOnBorrow" value="true"/>
            <property name="testOnReturn" value="true"/>
        </bean>
    
        
        <bean id = "jedisPool" class="redis.clients.jedis.JedisPool">
            <constructor-arg index="0" ref="jedisPoolConfig"/>
            <constructor-arg index="1" value="${redis.host}"/>
            <constructor-arg index="2" value="${redis.port}" type="int"/>
            <constructor-arg index="3" value="${redis.timeout}" type="int"/>
            <constructor-arg index="4" value="${redis.password}"/>
        </bean>
    
    </beans>