如何指定杰克逊只使用字段-最好是全局使用

默认的jackon行为似乎同时使用属性（getter和setter）和字段来序列化和反序列化为json。

我想将这些字段用作序列化配置的规范来源，因此根本不希望杰克逊查看属性。

我可以使用注解在单个类的基础上执行此操作：

 @JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)

但是我不想在每堂课上都讲这个...

是否可以全局配置？喜欢添加一些到对象映射器？

您可以这样配置各个ObjectMappers：

ObjectMapper mapper  = new ObjectMapper();
mapper.setVisibility(mapper.getSerializationConfig().getDefaultVisibilityChecker()
                .withFieldVisibility(JsonAutoDetect.Visibility.ANY)
                .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withSetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withCreatorVisibility(JsonAutoDetect.Visibility.NONE));

如果要全局设置，通常会通过包装器类访问已配置的映射器。

在Jackson 2.0及更高版本中，您可以简单地使用：

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;   

...

ObjectMapper mapper = new ObjectMapper();    
mapper.setVisibility(PropertyAccessor.ALL, Visibility.NONE);
mapper.setVisibility(PropertyAccessor.FIELD, Visibility.ANY);

关闭自动检测。

专门针对boolean is*()吸气剂：

我花了很多时间来解释为什么两个都不行

  @JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)

也不是

  setVisibility(PropertyAccessor.SETTER, JsonAutoDetect.Visibility.NONE);
  setVisibility(PropertyAccessor.GETTER, JsonAutoDetect.Visibility.NONE);
  setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);

为我的布尔型Getter / Setter工作。

解决方法很简单：

  @JsonAutoDetect(isGetterVisibility = Visibility.NONE, ...          
  setVisibility(PropertyAccessor.IS_GETTER, JsonAutoDetect.Visibility.NONE);

更新：spring-boot允许配置它：

jackson:
  visibility.field: any
  visibility.getter: none
  visibility.setter: none
  visibility.is-getter: none

请参阅通用应用程序属性＃JACKSON

对于杰克逊1.9.10，我使用

ObjectMapper mapper = new ObjectMapper();

mapper.setVisibility(JsonMethod.ALL, Visibility.NONE);
mapper.setVisibility(JsonMethod.FIELD, Visibility.ANY);

转到自动检测。

怎么样：我用了mixin

不符合规定的对象

@Entity
@Getter
@NoArgsConstructor
public class Telemetry {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long pk;
    private String id;
    private String organizationId;
    private String baseType;
    private String name;
    private Double lat;
    private Double lon;
    private Instant updateTimestamp;
}

混合：

@JsonAutoDetect(fieldVisibility = ANY, getterVisibility = NONE, setterVisibility = NONE)
public static class TelemetryMixin {}

用法：

    ObjectMapper om = objectMapper.addMixIn(Telemetry.class, TelemetryMixin.class);
    Telemetry[] telemetries = om.readValue(someJson, Telemetry[].class);

没有什么可以说您不能讲授任何数量的类并应用相同的mixin的。

如果您不熟悉mixin，则它们在概念上很简单：mixin的结构被强加到目标类上（根据jackson，就JVM而言）。

如果您想在全局范围内执行此操作而不必担心您的配置ObjectMapper，则可以创建自己的注释：

@Target({ElementType.ANNOTATION_TYPE, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@JacksonAnnotationsInside
@JsonAutoDetect(
        getterVisibility = JsonAutoDetect.Visibility.NONE, isGetterVisibility = JsonAutoDetect.Visibility.NONE,
        setterVisibility = JsonAutoDetect.Visibility.NONE, fieldVisibility = JsonAutoDetect.Visibility.NONE,
        creatorVisibility = JsonAutoDetect.Visibility.NONE
)
public @interface JsonExplicit {
}

现在，您只需使用注释您的课程，@JsonExplicit就可以开始了！

另外，请确保编辑上面的调用以@JsonAutoDetect确保您将值设置为适合您的程序的值。

感谢https://stackoverflow.com/a/13408807帮助我了解@JacksonAnnotationsInside

如果使用Spring Boot，则可以按以下方式全局配置Jackson ：

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

@Configuration
public class JacksonObjectMapperConfiguration implements Jackson2ObjectMapperBuilderCustomizer {

    @Override
    public void customize(Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder) {
        jacksonObjectMapperBuilder.visibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE);
        jacksonObjectMapperBuilder.visibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
        jacksonObjectMapperBuilder.visibility(PropertyAccessor.CREATOR, JsonAutoDetect.Visibility.ANY);
    }

}