# 27.1.3. 自定义JSON序列化器和反序列化器

如果使用Jackson序列化，反序列化JSON数据，你可能想编写自己的`JsonSerializer`和`JsonDeserializer`类。自定义序列化器（serializers）通常[通过Module注册到Jackson](http://wiki.fasterxml.com/JacksonHowToCustomDeserializers)，但Spring Boot提供了`@JsonComponent`注解这一替代方式，它能轻松的将序列化器注册为Spring Beans。

你可以在`JsonSerializer`或者`JsonDeserializer`的实现上，直接使用`@JsonComponent`注解。你也可以在以内部类的形式包含序列化器/反序列化器的类上使用它，如下所示：

```
import java.io.*;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import org.springframework.boot.jackson.*;

@JsonComponent
public class Example {

    public static class Serializer extends JsonSerializer<SomeObject> {
        // ...
    }

    public static class Deserializer extends JsonDeserializer<SomeObject> {
        // ...
    }

}
```

`ApplicationContext`里所有的`@JsonComponent` bean会自动注册到Jackson。因为`@JsonComponent`用`@Component`进行元注解，会应用通常的组件扫描规则。

Spring Boot也提供了[`JsonObjectSerializer`](https://github.com/spring-projects/spring-boot/tree/v2.0.0.RELEASE/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jackson/JsonObjectSerializer.java)和[`JsonObjectDeserializer`](https://github.com/spring-projects/spring-boot/tree/v2.0.0.RELEASE/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jackson/JsonObjectDeserializer.java)基础类。它们为标准的Jackson版本提供了替代选择。详情请查看[`JsonObjectSerializer`](https://docs.spring.io/spring-boot/docs/2.0.0.RELEASE/api/org/springframework/boot/jackson/JsonObjectSerializer.html)和[`JsonObjectDeserializer`](https://docs.spring.io/spring-boot/docs/2.0.0.RELEASE/api/org/springframework/boot/jackson/JsonObjectDeserializer.html)的Javadoc。


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