解决redis序列化java8 LocalDateTime错误的问题

本文介绍了解决Redis中使用Jackson序列化器存储包含LocalDateTime字段的对象时遇到的问题,并提供了解决方案。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

redis序列化选择方式

<!-- 缓存序列化方式 -->
    <!--对key的默认序列化器。默认值是StringSerializer-->
    <bean id="keySerializer" class="org.springframework.data.redis.serializer.StringRedisSerializer" />
    <!--是对value的默认序列化器,默认值是取自DefaultSerializer的JdkSerializationRedisSerializer。-->
    <bean id="valueSerializer" class="org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer" >
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
        <property name="connectionFactory"   ref="connectionFactory" />
        <!-- 这里修改了redis默认的序列化方式 -->
        <property name="keySerializer" ref="keySerializer" />
        <property name="valueSerializer" ref="valueSerializer" />
        <property name="hashKeySerializer" ref="keySerializer" />
        <property name="hashValueSerializer" ref="valueSerializer" />
    </bean>

要序列化class Demo

public class Demo {
    private Long id;
    private String name;
    private LocalDateTime time;
    ......
    }

操作存入redis中

@Test
public void test1() {
     Demo demo = new Demo();
     demo.setId(10000000001L);
     demo.setName("测试序列化");
     demo.setTime(LocalDateTime.now());
    redisTemplate.opsForValue().set("test", demo);
 }

在redis中查看

{
  "@class": "com.karmay3d.Demo",
  "id": 10000000001,
  "name": "测试序列化",
  "time": {
    "dayOfMonth": 15,
    "dayOfWeek": "TUESDAY",
    "dayOfYear": 227,
    "month": "AUGUST",
    "monthValue": 8,
    "year": 2017,
    "hour": 14,
    "minute": 45,
    "second": 51,
    "nano": 921000000,
    "chronology": {
      "@class": "java.time.chrono.IsoChronology",
      "id": "ISO",
      "calendarType": "iso8601"
    }
  }
}

LocalDateTime 存储的方式有问题。然后再从redis中取出Demo

@Test
    public void test2() {
        Demo demo = redisTemplate.opsForValue().get("test");
        System.out.println(demo.getId());
    }

报异常

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?)
 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?)
 at [Source: [B@68d651f2; line: 1, column: 81] (through reference chain: com.karmay3d.Demo["time"])
......
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?)
 at [Source: [B@68d651f2; line: 1, column: 81] (through reference chain: com.karmay3d.Demo["time"])
    at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:270)
    at com.fasterxml.jackson.databind.DeserializationContext.instantiationException(DeserializationContext.java:1456)
......

这个问题真的是纠结了几天。。。解决办法
mavan需要的jar包

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
    <version>${jackson.version}</version>
</dependency>

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

public class Demo {
    private Long id;
    private String name;
    @JsonDeserialize(using = LocalDateTimeDeserializer.class)
    @JsonSerialize(using = LocalDateTimeSerializer.class)
    private LocalDateTime time;
    ......
    }

redis再次存入之后结构

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

之后反序列化就可以取出Demo对象了。

解决这个问题查找的问答

### 解决 Redis 序列化 Java `LocalDateTime` 对象失败的方法 当使用 Redis 缓存含有 `LocalDateTime` 类型字段的类时,由于 Jackson 默认不支持此类型的序列化和反序列化,可能会引发异常。为了克服这一挑战,可以采取多种策略来确保数据能够被正确处理。 #### 方法一:利用自定义注解配置 通过在实体类中的 `LocalDateTime` 字段上添加特定注解,指明使用的序列化器与反序列化器: ```java import com.fasterxml.jackson.databind.annotation.JsonDeserialize; import com.fasterxml.jackson.databind.annotation.JsonSerialize; import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer; import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer; @JsonDeserialize(using = LocalDateTimeDeserializer.class) @JsonSerialize(using = LocalDateTimeSerializer.class) @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss") private LocalDateTime createTime; ``` 这种方法直接针对单个字段进行了优化设置[^3]。 #### 方法二:调整全局Jackson配置 如果希望整个应用程序范围内都应用这些更改,则可以在 Spring Boot 的配置文件中注册额外模块以增强 Jackson 功能: ```yaml spring: jackson: serialization.write_dates_as_timestamps: false deserialization.adjust_dates_to_context_time_zone: false ``` 并且,在启动类或其他合适位置引入 JSR310 模块的支持: ```java @Bean public Module jsr310Module() { return new JavaTimeModule(); } ``` 这一步骤使得所有日期时间格式都能得到一致性的解析[^1]。 #### 方法三:修改ObjectMapper默认行为 对于某些特殊情况下的需求,还可以考虑改变 ObjectMapper 实例的行为模式,比如启用更广泛的类型检测机制: ```java objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.EVERYTHING); ``` 不过需要注意的是,默认类型化的开启可能带来安全风险以及性能开销增加等问题,因此需谨慎评估后再做决定[^4]。 以上三种方式均可有效应对 Redis 中关于 `LocalDateTime` 的序列化难题,具体选择取决于项目的实际场景和个人偏好等因素。
评论 4
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值