今天在整合redis和spring boot的时候，遇到了一个错误，记录一下。
报错如下：
Could not read JSON: Cannot construct instance of `java.time.LocalDateTime` (no Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
查看后发现是数据从redis中取出时，Jackson2反序列化数据处理LocalDateTime类型时出错，原因是：Jackson2在序列化LocalDateTime时输出的不是普通的字符串时间格式，而是如下所示的格式（普通时间格式：2019-02-27 12:10:17）
{
"date": {
"year": 2019,
"month": "FEBRUARY",
"day": 27,
"dayOfMonth": 27,
"dayOfWeek": "WEDNESDAY",
"era": [
"java.time.chrono.IsoEra",
"CE"
],
"dayOfYear": 58,
"leapYear": false,
"chronology": {
"id": "ISO",
"calendarType": "iso8601"
},
"prolepticMonth": 24229,
"monthValue": 2
},
"time": {
"hour": 12,
"minute": 10,
"second": 17,
"nano": 0
},
"month": "FEBRUARY",
"year": 2019,
"dayOfMonth": 27,
"dayOfWeek": "WEDNESDAY",
"dayOfYear": 58,
"hour": 12,
"minute": 10,
"nano": 0,
"second": 17,
"monthValue": 2,
"chronology": [
"java.time.chrono.IsoChronology",
{
"id": "ISO",
"calendarType": "iso8601"
}
]
}
所以是Jackson2序列化LocalDateTime跟我们所预想的不一致，将注册给redis的序列化模板修改成以下就行
1 @Configuration 2 public class RedisConfig { 3 4 /** 5 * 定义 UserRedisTemplate ，指定序列化和反序列化的处理类 6 * 7 * @param factory redis连接工厂 8 * @return 模板 9 */ 10 @Bean("UserRedisTemplate") 11 public RedisTemplate<String, User> userRedisTemplate(RedisConnectionFactory factory) { 12 RedisTemplate<String, User> template = new RedisTemplate<>(); 13 template.setConnectionFactory(factory); 14 Jackson2JsonRedisSerializer<User> j2jrs = new Jackson2JsonRedisSerializer<>(User.class); 15 ObjectMapper om = new ObjectMapper(); 16 om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); 17 // 解决jackson2无法反序列化LocalDateTime的问题 18 om.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS); 19 om.registerModule(new JavaTimeModule()); 20 om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY); 21 j2jrs.setObjectMapper(om); 22 // 序列化 value 时使用此序列化方法 23 template.setValueSerializer(j2jrs); 24 template.setHashValueSerializer(j2jrs); 25 // 序列化 key 时 26 StringRedisSerializer srs = new StringRedisSerializer(); 27 template.setKeySerializer(srs); 28 template.setHashKeySerializer(srs); 29 template.afterPropertiesSet(); 30 return template; 31 } 32 }
主要是加上标红的那两句
参考文档：