Redis指定db存储教程

ゝ一纸荒年。 2021-11-01 03:48 1226阅读 0赞

今天，日月教大家如何存储数据到redis的指定db中，熟悉redis的都知道，redis默认是有16个db的，如图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70]  
上图中redis图形化管理工具安装请查看：[Redis管理工具TreeNMS][Redis_TreeNMS]

OK，为了节省时间，我们直接在之前的 [springBoot集成redis][springBoot_redis] 该项目基础上修改。

**一、修改RedisUtils**

新增三个方法：

/**
         * 
        * @Title: set
        * @Description: 写入缓存并指定库
        * @param key
        * @param value 为对象时flag_json必须为true
        * @param db    缓存的数据库
        * @param flag_json  是否将value值转为json
        * @param timeOut  时效（秒）   永久传null
        * @return boolean
         */
        public boolean set(final String key, Object value,int db,boolean flag_json,Long timeOut) {
            boolean result = false;
            try {
                RedisConnection redisConnection = redisTemplate.getConnectionFactory().getConnection();
                DefaultStringRedisConnection stringRedisConnection = new DefaultStringRedisConnection(redisConnection);
                stringRedisConnection.select(db);
                if(flag_json){
                    stringRedisConnection.set(key, JsonUtils.object2Json(value));
                }else{
                    stringRedisConnection.set(key, value.toString());
                }
                if(timeOut != null && timeOut != 0){
                    stringRedisConnection.expire(key, timeOut);
                }
                stringRedisConnection.close();
                result = true;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return result;
        }
        
        /**
         * 
        * @Title: get
        * @Description: 读取指定db的缓存
        * @param key
        * @param db
        * @return Object
         */
        public Object get(final String key,int db) {
            Object result = null;
            try {
                RedisConnection redisConnection = redisTemplate.getConnectionFactory().getConnection();
                DefaultStringRedisConnection stringRedisConnection = new DefaultStringRedisConnection(redisConnection);
                stringRedisConnection.select(db);
                result = stringRedisConnection.get(key);
                stringRedisConnection.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return result;
        }
        
        /**
         * 删除指定db的key
         *
         * @param key
         * @param db
         */
        public void remove(final String key ,int db) {
            try {
                RedisConnection redisConnection = redisTemplate.getConnectionFactory().getConnection();
                DefaultStringRedisConnection stringRedisConnection = new DefaultStringRedisConnection(redisConnection);
                stringRedisConnection.select(db);
                if(stringRedisConnection.exists(key)){
                    stringRedisConnection.del(key);
                }
                stringRedisConnection.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

**二、controller添加测试请求**

/**
     * 
    * @Title: saveCache
    * @Description: redis 指定db存储测试
    * @param db
    * @return String
     */
    @RequestMapping(value = "/saveCache/{db}")
    public String saveCache(@PathVariable("db") int db){
        redisUtils.set("test", "我存储在redis的db " + db, db, false, null);
        return redisUtils.get("test", db).toString();
    }

**三、测试**

我们先将redis中db1至db3中的数据清空

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 1]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 2]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 3]

打开浏览器，分别请求：  
localhost:8002/saveCache/1  
localhost:8002/saveCache/2  
localhost:8002/saveCache/3

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 4]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 5]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 6]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 7]  
OK，可以看到，测试成功，数据成功存储到指定的db中了。

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[Redis_TreeNMS]: https://blog.csdn.net/weixin_40623736/article/details/99110193
[springBoot_redis]: https://blog.csdn.net/weixin_40623736/article/details/98097708
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