转载

SpringBoot下使用redis

当我们项目需要使用缓存并且高并发的时候，可以使用redis连接池，让我们直奔主题。本文项目环境win 10，springboot 2.1.5.RELEASE，redis Java客户端jedis 2.9.3，fastjson 1.2.47(用于序列化)。本项目使用了lombok插件，所以set，get方法用注解代替。

1.引入redis客户端依赖

<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
</dependency>

2.在application.properties文件中添加配置

#redis
redis.host=127.0.0.1
redis.port=6379
redis.timeout=10
redis.poolMaxTotal=1000
redis.poolMaxIdle=500
redis.poolMaxWait=500

3.编写实体类RedisConfig接收配置

/**
 * 读取配置文件的redis信息
 */
@Data
@Component
@ConfigurationProperties(prefix = "redis")//会读取前缀为redis的配置
public class  RedisConfig {
    private String host;
    private int port;
    private int timeout;
    private String password;
    private int poolMaxTotal;
    private int poolMaxIdle;
    private int poolMaxWait;
}

4.编写RedisPoolFactory类，该类返回一个redis连接池。

@Service
public class RedisPoolFactory {

    @Autowired
    RedisConfig  redisConfig;

    /**
     * 将redis连接池注入spring容器
     * @return
     */
    @Bean
    public JedisPool JedisPoolFactory(){
        JedisPoolConfig config = new JedisPoolConfig();
        config.setMaxIdle(redisConfig.getPoolMaxIdle());
        config.setMaxTotal(redisConfig.getPoolMaxTotal());
        config.setMaxWaitMillis(redisConfig.getPoolMaxWait() * 1000);
        JedisPool jp = new JedisPool(config, redisConfig.getHost(), redisConfig.getPort(),
                redisConfig.getTimeout()*1000, redisConfig.getPassword(), 0);
        return jp;
    }

}

5.自己编写redis方法类

重写的方法会给key加上前缀，好处就是可以分类，避免重复和批量删除

@Service
public class RedisService {

    @Autowired
    JedisPool jedisPool;

    /**
     * 从redis连接池获取redis实例
     */
    public <T> T get(KeyPrefix prefix, String key, Class<T> clazz) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //对key增加前缀，即可用于分类，也避免key重复
            String realKey = prefix.getPrefix() + key;
            String str = jedis.get(realKey);
            T t = stringToBean(str, clazz);
            return t;
        } finally {
            returnToPool(jedis);
        }

    }

    /**
     * 存储对象
     */
    public <T> Boolean set(KeyPrefix prefix, String key, T value) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String str = beanToString(value);
            if (str == null || str.length() <= 0) {
                return false;
            }
            String realKey = prefix.getPrefix() + key;
            int seconds = prefix.expireSeconds();//获取过期时间
            if (seconds <= 0) {
                jedis.set(realKey, str);
            } else {
                jedis.setex(realKey, seconds, str);
            }

            return true;
        } finally {
            returnToPool(jedis);
        }

    }

    /**
     * 删除
     */
    public boolean delete(KeyPrefix prefix, String key) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            long ret = jedis.del(realKey);
            return ret > 0;
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 判断key是否存在
     */
    public <T> boolean exists(KeyPrefix prefix, String key) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            return jedis.exists(realKey);
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 增加值
     * Redis Incr 命令将 key 中储存的数字值增一。    如果 key 不存在，那么 key 的值会先被初始化为 0 ，然后再执行 INCR 操作
     */
    public <T> Long incr(KeyPrefix prefix, String key) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            return jedis.incr(realKey);
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 减少值
     */
    public <T> Long decr(KeyPrefix prefix, String key) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix() + key;
            return jedis.decr(realKey);
        } finally {
            returnToPool(jedis);
        }
    }


    public static <T> String beanToString(T value) {
        if (value == null) {
            return null;
        }
        Class<?> clazz = value.getClass();
        if (clazz == int.class || clazz == Integer.class) {
            return String.valueOf(value);
        } else if (clazz == long.class || clazz == Long.class) {
            return String.valueOf(value);
        } else if (clazz == String.class) {
            return (String) value;
        } else {
            return JSON.toJSONString(value);
        }

    }

    public static <T> T stringToBean(String str, Class<T> clazz) {
        if (str == null || str.length() <= 0 || clazz == null) {
            return null;
        }
        if (clazz == int.class || clazz == Integer.class) {
            return (T) Integer.valueOf(str);
        } else if (clazz == long.class || clazz == Long.class) {
            return (T) Long.valueOf(str);
        } else if (clazz == String.class) {
            return (T) str;
        } else {
            return JSON.toJavaObject(JSON.parseObject(str), clazz);
        }
    }

    private void returnToPool(Jedis jedis) {
        if (jedis != null) {
            jedis.close();//不是关闭，只是返回连接池
        }
    }

}

6.测试

@Test
    public void RedisServiceTest() {
        Boolean aBoolean = redisService.set(GoodsKey.getGoodsStock, "huawei", "500");
        System.out.println(aBoolean);//aBoolean=true
    }