Spring boot 来自Jackson的NPE试图序列化不存在的字段?
这是我的简单豆子Spring boot 来自Jackson的NPE试图序列化不存在的字段?,spring-boot,jackson2,jackson-databind,Spring Boot,Jackson2,Jackson Databind,这是我的简单豆子 @Data @NoArgsConstructor @AllArgsConstructor @Builder public class Foo { private String firstName; private String lastName; public String getFullName(){ return firstName + lastName; } } 当此对象在Spring boot controller中与J
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Foo {
private String firstName;
private String lastName;
public String getFullName(){
return firstName + lastName;
}
}
当此对象在Spring boot controller中与Jackson一起序列化时,
我得到以下错误
j.l.NullPointerException: null
com.example.foobar.foo.getFullName(Foo.java:28)
s.r.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java)
s.r.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
s.r.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
j.l.reflect.Method.invoke(Method.java:498)
c.f.j.d.s.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:653)
c.f.j.d.s.s.BeanSerializerBase.serializeFields(BeanSerializerBase.java:690)..
28 common frames omitted\nWrapped by: c.f.j.d.JsonMappingException: (was java.lang.NullPointerException)
(through reference chain: com.example.foobar.foo[\"fullName\"])
c.f.j.d.JsonMappingException.wrapWithPath(JsonMappingException.java:379)
c.f.j.d.JsonMappingException.wrapWithPath(JsonMappingException.java:339)
c.f.j.d.s.s.StdSerializer.wrapAndThrow(StdSerializer.java:343)
c.f.j.d.s.s.BeanSerializerBase.serializeFields(BeanSerializerBase.java:698)
c.f.j.d.s.BeanSerializer.serialize(BeanSerializer.java:155)
c.f.j.d.s.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:292)
c.f.j.d.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1419)
c.f.j.d.ObjectWriter.writeValue(ObjectWriter.java:940)
o.s.h.c.j.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:267)...
23 common frames omitted\nWrapped by: o.s.h.c.HttpMessageNotWritableException: Could not write content: (was java.lang.NullPointerException) (through reference chain: com.example.foobar.foo[\"fullName\"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: com.example.foobar.foo[\"fullName\"])
o.s.h.c.j.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:274 ..."
这是我发送的请求主体
{"firstName": "foo",
"lastName: null
}
Jackson正在尝试序列化fullName属性吗?但我没有声明这样的字段。这是预期的行为吗?我找不到支持此行为的文档
谢谢您的猜测是对的,Jackson正试图通过其getter方法找到字段名,但它找不到。因此,NPE 不同的解决方案
@JsonIgnore
李>
spring.jackson.mapper.使用getter作为setter=false
@Bean
public Jackson2ObjectMapperBuilder objectMapperBuilder() {
Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
builder.featuresToDisable(MapperFeature.USE_GETTERS_AS_SETTERS);
return builder;
}
是的,你是对的。对getFullName方法使用
@JsonIgnore
。另外,我建议使用@Getter
和@Setter
而不是@Data
@pvpkiran为什么不使用@Data呢?没有什么错。但我发现@Data与Jackson的反序列化并不协调。只是一个建议