redis 存取报错

以你之姓@ 2022-05-27 12:16 253阅读 0赞

redis  存非string报java.lang.ClassCastException

使得存不进去

修改配置文件添加 支持序列化代码

package com.lenovo.pcsd.bp.businesspartner.config;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.cache.CacheManager;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.data.redis.cache.RedisCacheManager;
    import org.springframework.data.redis.core.StringRedisTemplate;
    import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
    
    /**
     * Created by freezhan on 16/9/5.
     */
    @Configuration
    public class CacheConfig {
        //过期时间
        @Value("${redisDefaultExpiration}")
        private long redisDefaultExpiration;
    
    
        //缓存key前缀
        @Value("${spring.application.name}")
        private String cachePrefix;
    
    
        @Autowired
        private StringRedisTemplate redisTemplate;
    
        @Bean
        public CacheManager cacheManager() {
            RedisCacheManager manage = new RedisCacheManager(redisTemplate);
            manage.setDefaultExpiration(redisDefaultExpiration);
            manage.setCachePrefix(new RedisPrefix(cachePrefix));
            //一下代码为新增
             redisTemplate.setHashValueSerializer(new Jackson2JsonRedisSerializer<>(Object.class));
            redisTemplate.setKeySerializer(new Jackson2JsonRedisSerializer<>(Object.class));
            redisTemplate.setValueSerializer(new Jackson2JsonRedisSerializer<>(Object.class));
            redisTemplate.setHashKeySerializer(new Jackson2JsonRedisSerializer<>(Object.class));
            manage.setUsePrefix(true);
            return  manage;
        }
    
    }

redis  存非string报

java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to

有资料说 热部署依赖包冲突   删除了还是没有解决

<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-devtools</artifactId>
    			<optional>true</optional>
    		</dependency>

最终解决方案

@Bean
        public CacheManager cacheManager() {
            RedisCacheManager manage = new RedisCacheManager(redisTemplate);
            manage.setDefaultExpiration(redisDefaultExpiration);
            manage.setCachePrefix(new RedisPrefix(cachePrefix));
            redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
            redisTemplate.setKeySerializer(new GenericJackson2JsonRedisSerializer());
            redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
            redisTemplate.setHashKeySerializer(new GenericJackson2JsonRedisSerializer());
            manage.setUsePrefix(true);
            return  manage;
        }
    
    }

JacksonJsonRedisSerializer和GenericJackson2JsonRedisSerializer，两者都能系列化成json，但是后者会在json中加入@class属性，类的全路径包名，方便反系列化。前者如果存放了List则在反系列化的时候如果没指定TypeReference则会报错java.util.LinkedHashMap cannot be cast to

{
      "@class": "com.vo.ResultVO",
      "code": 0,
      "msg": "成功",
      "data": {
        "@class": "com.utils.PageUtil",
        "number": 5,
        "size": 2,
        "numberOfElements": 2,
        "totalElements": 597,
        "totalPages": 299,
        "content": [
          "com.github.pagehelper.Page",
          [
            {
              "@class": "java.util.HashMap",
              "productgroupid": "B3",
              "shoptypename": "钻石级",
              "season3": 0,
              "citydis": "3U",
              "season4": 0,
              "id": 66,
              "season1": 0,
              "season2": 0
            },
            {
              "@class": "java.util.HashMap",
              "productgroupid": "B3",
              "shoptypename": "全星级",
              "season3": 0,
              "citydis": "3U",
              "season4": 0,
              "id": 67,
              "season1": 0,
              "season2": 0
            }
          ]
        ]
      }
    }

可以看到保存到redis数据库中的数据是json，并且每个节点都有@class属性，这些属性在凡系列化时会使用到