默认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。
我想使用字段作为序列化配置的规范源，因此不希望jackson查看所有属性。
我可以用注释在单个类的基础上做到这一点:
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)
但我不想在每节课上都这么做……
是否可以全局配置?比如添加一些到对象映射器?
当前回答
如果你想要一种方法来全局地做这件事，而不用担心你的ObjectMapper的配置，你可以创建你自己的注释:
@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 {
}
现在只需要用@JsonExplicit注释类就可以了!
还要确保编辑上述对@JsonAutoDetect的调用，以确保将值设置为适合程序的值。
感谢https://stackoverflow.com/a/13408807帮助我找到@JacksonAnnotationsInside
其他回答
你可以像这样配置单个的objectmapper:
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));
如果希望全局设置，我通常通过包装器类访问已配置的映射器。
在Jackson 2.0及以后版本中，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。
如果您使用Spring Boot，您可以全局配置Jackson，如下所示:
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);
}
}
这个怎么样:我把它和mixin一起用了
不一致的对象
@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);
没有人说你不能在任意数量的类中应用相同的mixin。
如果您不熟悉mixin，那么它们在概念上很简单:mixin的结构是超级强加在目标类上的(根据jackson的说法，就JVM而言不是这样)。
我使用的是jackson 1.9.10
ObjectMapper mapper = new ObjectMapper();
mapper.setVisibility(JsonMethod.ALL, Visibility.NONE);
mapper.setVisibility(JsonMethod.FIELD, Visibility.ANY);
开启自动还原。
