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。
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