redis序列化選擇方式

<!-- 快取序列化方式 -->
    <!--對key的預設序列化器。預設值是StringSerializer-->
    <bean id="keySerializer" class="org.springframework.data.redis.serializer.StringRedisSerializer" />
    <!--是對value的預設序列化器，預設值是取自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" />
        <!-- 這裡修改了redis預設的序列化方式 -->
 

        <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("測試序列化");
     demo.setTime(LocalDateTime.now());
    redisTemplate.opsForValue().set("test", demo);
 }

在redis中檢視

{
  "@class": "com.karmay3d.Demo",
  "id": 10000000001,
  "name": "測試序列化",
  "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 儲存的方式有問題。然後再從redis中取出Demo

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

報異常

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: [[email protected]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: [[email protected]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: [[email protected]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)
......

這個問題真的是糾結了幾天。。。解決辦法
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屬性加上註解
@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再次存入之後結構

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

之後反序列化就可以取出Demo物件了。