Java操作Redis---工具封装简单示例

自己平时写代码时用到的，SpringBoot整合Redis，这里只写写如何封装常用操作。这里使用redis连接池，方便操作。

1、构建实体类：通过实体类来传递参数

1.1、先看配置文件

#redis
redis.host=127.0.0.1
redis.port=6379
redis.timeout=3
redis.password=123456
redis.poolMaxTotal=10
redis.poolMaxIdle=10
redis.poolMaxWait=3

1.2、根据配置文件的属性来设计实体类

@Component
@ConfigurationProperties(prefix = "redis") //把同类的配置信息自动封装成实体类
public class RedisConfig {
    private String host;
    private Integer port;
    private Integer timeout;  //秒
    private String password;

    private Integer poolMaxTotal;
    private Integer poolMaxIdle;
    private Integer poolMaxWait;//秒

    ......//getter+setter
}

2、构建连接池：根据参数配置，返回自定义连接池

@Service
public class RedisPoolFactory {
    @Autowired
    private RedisConfig redisConfig;

    @Bean
    public JedisPool JedisPoolFactory() {
        JedisPoolConfig poolConfig = new JedisPoolConfig();
        poolConfig.setMaxIdle(redisConfig.getPoolMaxIdle());
        poolConfig.setMaxTotal(redisConfig.getPoolMaxTotal());
        poolConfig.setMaxWaitMillis(redisConfig.getPoolMaxWait() * 1000);
        JedisPool jp = new JedisPool(poolConfig, redisConfig.getHost(), redisConfig.getPort(),
                redisConfig.getTimeout()*1000, redisConfig.getPassword(), 0);
        return jp;
    }
}

3、封装操作：通过连接池，获得jedis对象完成具体操作

@Service
public class RedisService {

    @Autowired
    JedisPool jedisPool;

    /**
     * 获取对象
     * */
    public <T> T get(KeyPrefix prefix, String key,  Class<T> clazz) {
        Jedis jedis = null;
        try {
            jedis =  jedisPool.getResource();
            //生成真正的key
            String realKey  = prefix.getPrefix() + key;
            String  str = jedis.get(realKey);
            T t =  stringToBean(str, clazz);
            return t;
        }finally {
            returnToPool(jedis);
        }
    }

    /**
     * 设置对象
     * */
    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;
            }
            //生成真正的key
            String realKey  = prefix.getPrefix() + key;
            int seconds =  prefix.expireSeconds();
            if(seconds <= 0) {
                jedis.set(realKey, str);
            }else {
                jedis.setex(realKey, seconds, str);
            }
            return true;
        }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
     * */
    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);
        }
    }

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

    @SuppressWarnings("unchecked")
    private <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 == String.class) {
            return (T)str;
        }else if(clazz == long.class || clazz == Long.class) {
            return  (T)Long.valueOf(str);
        }else {
            return JSON.toJavaObject(JSON.parseObject(str), clazz);
        }
    }

    private void returnToPool(Jedis jedis) {
        if(jedis != null) {
            jedis.close();
        }
    }

}

其中的KeyPrefix类，是为了保证key的唯一性，也是为了方便区分各种key而加的前缀，详情请见

通用缓存Key的封装