springboot中Jackson 枚举对象 和code 自动转换

在Spring Boot中使用Jackson自动转换枚举对象和code可以通过以下步骤实现：

1. 定义枚举类并添加code属性和对应的构造函数：

public enum Gender {
    MALE("M"), FEMALE("F");

    private String code;

    Gender(String code) {
        this.code = code;
    }

    public String getCode() {
        return code;
    }
}

2. 在实体类中使用枚举类：

public class User {
    private String name;
    private Gender gender;
    
    // getter and setter
}

3. 配置Jackson的ObjectMapper，使其能够自动转换枚举对象和code：

@Configuration
public class JacksonConfig {

    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        SimpleModule module = new SimpleModule();
        module.addDeserializer(Gender.class, new GenderDeserializer());
        module.addSerializer(Gender.class, new GenderSerializer());
        objectMapper.registerModule(module);
        return objectMapper;
    }

    private static class GenderDeserializer extends JsonDeserializer<Gender> {
        @Override
        public Gender deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
            String code = p.getValueAsString();
            return Gender.valueOf(code.toUpperCase());
        }
    }

    private static class GenderSerializer extends JsonSerializer<Gender> {
        @Override
        public void serialize(Gender value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
            gen.writeString(value.getCode());
        }
    }
}

4. 在控制器中使用实体类：

@RestController
public class UserController {

    @PostMapping("/user")
    public User createUser(@RequestBody User user) {
        return user;
    }
}

现在，当我们发送以下请求时：

POST /user
{
    "name": "John",
    "gender": "M"
}

我们将得到以下响应：

{
    "name": "John",
    "gender": "M"
}

可以看到，枚举对象和code已经自动转换了