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:
GenericJackson2JsonRedisSerializer 反序列化问题
来源:oschina
链接:https://my.oschina.net/u/4411942/blog/3632166