您好，我是码农飞哥，感谢您阅读本文！最近在进行框架改造，历史遗留代码对Redis的使用不当，导致了一些问题。
问题描述
org.springframework.data.redis.serializer.SerializationException: Cannot deserialize; nested exception is org.springframework.core.serializer.support.SerializationFailedException: Failed to deserialize payload. Is the byte array a result of corresponding serialization for DefaultDeserializer?; nested exception is org.springframework.core.NestedIOException: Failed to deserialize object type; nested exception is java.lang.ClassNotFoundException: com.coep.model.domain.UserCache at org.springframework.data.redis.serializer.JdkSerializationRedisSerializer.deserialize(JdkSerializationRedisSerializer.java:84)
从问题的描述我们就可以轻松的定位到这是由于调用JdkSerializationRedisSerializer的deserialize方法对redis值进行反序列化时报的错。
问题分析
错误提示是ClassNotFoundException: com.coep.model.domain.UserCache，这个UserCache类找不到了，为啥找不到呢，这是由于我们在进行框架改造时变更了类的包名。所以，反序列化类时就找不到了。原有的对redis的操作类。
对redis使用的错误示范
private static RedisSerializer<Object> jdkRedisSerializer = new JdkSerializationRedisSerializer(); private static RedisSerializer<String> stringRedisSerializer = new StringRedisSerializer(); public boolean set(final String key, final Object obj, final long seconds) { // key的组织形式 namespace:id:parmeter strRedisTemplate.execute((RedisCallback<Serializable>) connection -> { final byte[] keyBytes = stringRedisSerializer.serialize(key); final byte[] name = jdkRedisSerializer.serialize(obj); connection.setEx(keyBytes, seconds, name); return null; }); return true; } @Override public Serializable get(final Serializable key) { return strRedisTemplate.execute((RedisCallback<Serializable>) connection -> { byte[] keyBytes = stringRedisSerializer.serialize( key); byte[] bytes = connection.get(keyBytes); return (Serializable) jdkRedisSerializer.deserialize(bytes); }); }
这里设置键值时，对key使用的是StringRedisSerializer进行序列化，对value使用的是JdkSerializationRedisSerializer进行序列化。序列化后的数据类型是二进制的字节码文件，可视性差。而且使用JdkSerializationRedisSerializer序列化性能比较差，所以不推荐使用。
正确的姿势
对于历史的记录，只能在报错之后删除掉该key。这里推荐使用StringRedisSerializer来序列化key和value。相关的配置如下：
使用RedisTemplate操作类的配置如下：
@Primary @Bean public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { try { //测试连通性 factory.getConnection(); } catch (RedisConnectionFailureException e) { LOGGER.warn("未发现redis服务。"); redisAvailable = false; } RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>(); redisTemplate.setKeySerializer(new StringRedisSerializer()); redisTemplate.setHashKeySerializer(new StringRedisSerializer()); redisTemplate.setHashValueSerializer(new StringRedisSerializer()); redisTemplate.setValueSerializer(new StringRedisSerializer()); redisTemplate.setConnectionFactory(factory); return redisTemplate; }
或者直接使用StringRedisTemplate操作类的配置如下：
@Bean public StringRedisTemplate stringRedisTemplate(JedisConnectionFactory redisConnectionFactory) { StringRedisTemplate stringRedisTemplate = new StringRedisTemplate(redisConnectionFactory); return stringRedisTemplate; }
