Java爬坑

redis序列化选择方式

1 1  public CacheManager cacheManager(RedisTemplate redisTemplate) {
2 2         //设置序列化Key的实例化对象
3 3         redisTemplate.setKeySerializer(new StringRedisSerializer());
4 4         //设置序列化Value的实例化对象
5 5         redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
6 6         RedisCacheManager redisCacheManager = new RedisCacheManager(redisTemplate);
7 7         // 使用前缀
8 8         redisCacheManager.setUsePrefix(true);
9 9         redisCacheManager.setCachePrefix(new DefaultRedisCachePrefix(":"));
1010         // 设置默认缓存的过期时间
1111         redisCacheManager.setDefaultExpiration(86400);// 一天
1212     
1313         redisCacheManager.setExpires(expires);
1414 
1515         return redisCacheManager;

要序列化class Demo

11 public class Demo {
22     private Long id;
33     private String name;
44     private LocalDateTime time;
55    
66 }

在redis中查看

1 1 {
2 2   "@class": "com.karmay3d.Demo",
3 3   "id": 10000000001,
4 4   "name": "测试序列化",
5 5   "time": {
6 6     "dayOfMonth": 15,
7 7     "dayOfWeek": "TUESDAY",
8 8     "dayOfYear": 227,
9 9     "month": "AUGUST",
1010     "monthValue": 8,
1111     "year": 2017,
1212     "hour": 14,
1313     "minute": 45,
1414     "second": 51,
1515     "nano": 921000000,
1616     "chronology": {
1717       "@class": "java.time.chrono.IsoChronology",
1818       "id": "ISO",
1919       "calendarType": "iso8601"
2020     }
2121   }
2222 }

报的异常

11 org.springframework.data.redis.serializer.SerializationException: Could not read JSON: Can not construct instance of java.time.LocalDateTime: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?)
22  at [Source: [B@68d651f2; line: 1, column: 81] (through reference chain: com.karmay3d.Demo["time"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of java.time.LocalDateTime: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?)
33  at [Source: [B@68d651f2; line: 1, column: 81] (through reference chain: com.karmay3d.Demo["time"])
44 ......
55 Caused by: com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of java.time.LocalDateTime: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?)
66  at [Source: [B@68d651f2; line: 1, column: 81] (through reference chain: com.karmay3d.Demo["time"])
77     at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:270)
88     at com.fasterxml.jackson.databind.DeserializationContext.instantiationException(DeserializationContext.java:1456)
99 ......

修改

LocalDateTime属性加上注解
@JsonDeserialize(using = LocalDateTimeDeserializer.class)
@JsonSerialize(using = LocalDateTimeSerializer.class)

11 public class Demo {
22     private Long id;
33     private String name;
44     @JsonDeserialize(using = LocalDateTimeDeserializer.class)
55     @JsonSerialize(using = LocalDateTimeSerializer.class)
66     private LocalDateTime time;
77     ......
88     }

redis里面对象

11 {
22   "@class": "com.karmay3d.Demo",
33   "id": 10000000001,
44   "name": "测试序列化",
55   "time": [2017,8,15,14,57,37,525000000]
66 }

然后就可以解决问题了

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