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redis中如何存储java对象

根据 redis 的存储原理,Redis 的 key 和 value 都支持二进制安全的字符串

1. 利用序列化和反序列化的方式

存储 java 对象我们可以通过对象的序列化与反序列化完成存储于取出, 这样就可以使用 redis 存储 java 对象了

a. 利用 jdk 自带的序列化机制，但效率不高

步骤: 创建一个序列化和反序列化的工具类

public class SerializeUtil {  
public static byte[] serialize(Object object) {  
ObjectOutputStream oos = null;  
ByteArrayOutputStream baos = null;  
try {  
//序列化  
baos = new ByteArrayOutputStream();  
oos = new ObjectOutputStream(baos);  
oos.writeObject(object);  
byte[] bytes = baos.toByteArray();  
return bytes;  
} catch (Exception e) { }  
return null;  
}  
public static Object unserialize(byte[] bytes) {  
ByteArrayInputStream bais = null;  
try {  
//反序列化  
bais = new ByteArrayInputStream(bytes);  
ObjectInputStream ois = new ObjectInputStream(bais);  
return ois.readObject();} catch (Exception e) { }  
return null;  
}  
}

b. 利用谷歌的序列化依赖，高效，使用于秒杀等业务场景

<!--prostuff 序列化依赖 -->
<dependency>
<groupId>com.dyuproject.protostuff</groupId>
<artifactId>protostuff-core</artifactId>
<version>1.0.8</version>
</dependency>
<dependency>
<groupId>com.dyuproject.protostuff</groupId>
<artifactId>protostuff-runtime</artifactId>
<version>1.0.8</version>
</dependency>
@Slf4j
public class RedisDao {

</span><span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">final</span><span style="color: rgba(0, 0, 0, 1)"> JedisPool jedisPool;
</span><span style="color: rgba(0, 0, 255, 1)">private</span> RuntimeSchema&lt;Seckill&gt; schema = RuntimeSchema.createFrom(Seckill.<span style="color: rgba(0, 0, 255, 1)">class</span><span style="color: rgba(0, 0, 0, 1)">);

</span><span style="color: rgba(0, 0, 255, 1)">public</span> RedisDao(String ip, <span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> port) {
    jedisPool </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> JedisPool(ip, port);
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> Seckill getSeckill(Long seckillId) {
    Jedis jedis </span>= <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)"> {
        jedis </span>=<span style="color: rgba(0, 0, 0, 1)"> jedisPool.getResource();
        String key </span>= "seckill:" +<span style="color: rgba(0, 0, 0, 1)"> seckillId;
        </span><span style="color: rgba(0, 0, 255, 1)">byte</span>[] bytes =<span style="color: rgba(0, 0, 0, 1)"> jedis.get(key.getBytes());
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (bytes != <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
            Seckill seckill </span>=<span style="color: rgba(0, 0, 0, 1)"> schema.newMessage();
            ProtostuffIOUtil.mergeFrom(bytes, seckill, schema);
            </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> seckill;
        }
    } </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (Exception e) {
        log.error(e.getMessage(), e);
    } </span><span style="color: rgba(0, 0, 255, 1)">finally</span><span style="color: rgba(0, 0, 0, 1)"> {
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (jedis != <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
            jedis.close();
        }
    }
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String putSeckill(Seckill seckill) {
    Jedis jedis </span>= <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
    </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)"> {
        jedis </span>=<span style="color: rgba(0, 0, 0, 1)"> jedisPool.getResource();
        String key </span>= "seckill:" +<span style="color: rgba(0, 0, 0, 1)"> seckill.getSeckillId();
        </span><span style="color: rgba(0, 0, 255, 1)">byte</span>[] bytes =<span style="color: rgba(0, 0, 0, 1)"> ProtostuffIOUtil.toByteArray(seckill, schema, LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE));
        Integer timeout </span>= 60 * 60<span style="color: rgba(0, 0, 0, 1)">;
        String result </span>=<span style="color: rgba(0, 0, 0, 1)"> jedis.setex(key.getBytes(), timeout, bytes);
        </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> result;
    } </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (Exception e) {
        log.error(e.getMessage(), e);
    } </span><span style="color: rgba(0, 0, 255, 1)">finally</span><span style="color: rgba(0, 0, 0, 1)"> {
        </span><span style="color: rgba(0, 0, 255, 1)">if</span> (jedis != <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">) {
            jedis.close();
        }
    }

    </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">;
}



}

 

方法 2: 将 java 对象转换为 json 字符串, 利用 json 与 java 对象之间可以相互转换的方式进行存值和取值