Question

我有以下情况：

public class A {

    @JsonProperty("member")
    private int Member;
}

public class B {

    private int Member;
}

现在，我希望做到以下几点：

ObjectMapper mapper = new ObjectMapper();
B b = new B(); b.setMember("1");

A a = mapper.converValue(b, A.class);

通常情况下，这会奏效。但是，由于objectMapper考虑了@JsonProperty等注释，因此我得到以下结果：

A.getMember(); // Member = NULL

有一种解决方法，其中由于此而预期为null的所有字段都是手动设置的，即A.setMember(b.getMember());，但这违背了在objectMapper中使用objectMapper的目的。第一名并且可能容易出错。

有没有办法配置@JsonProperty忽略给定类（或全局）的#!/bin/bash test -r "$1" || { ## validate first argument is readable file printf "error: file not given or not readable.\n" exit 1 } while read -ra line; do ## read each line into array if test -z "$headings" ; then ## if headign not set, set it headings=1 ## set heading used flag printf "%s" "${line[0]}" ## print Individual ## duplicate each heading tab separated for ((i = 1; i < ${#line[@]}; i++)); do printf "\t%s\t%s" "${line[i]}" "${line[i]}" done echo "" ## tidy up with newline elif test -z "$line1" ; then ## if line1 not set, set it line1=( "${line[@]}" ) ## save line as line1 and get next line else ## test that persons match if test "${line1[0]}" = "${line[0]}" ; then ## test number of fields in each line match if test "${#line1[@]}" != "${#line[@]}" ; then printf "error: field mismatch - person '%s'.\n" "${line[0]}" >&2 fi printf "%s\t" "${line[0]}" ## print the person (w/tab) ## interleave data for person from line1 line2 tab separated for ((i = 1; i < ${#line[@]}; i++)); do printf "\t%s\t%s" "${line1[i]}" "${line[i]}" done echo "" ## tidy up with newline line1= ## unset line1 and repeat fi fi done < "$1"字段？

Answer 1

您可以通过执行以下操作来配置ObjectMapper以忽略@JsonProperty之类的注释：

ObjectMapper objectMapper = new ObjectMapper().configure(
             org.codehaus.jackson.map.DeserializationConfig.Feature.USE_ANNOTATIONS, false)
                .configure(org.codehaus.jackson.map.SerializationConfig.Feature.USE_ANNOTATIONS, false)

但这会导致它也忽略像@JsonIgnore等等。我不知道有什么办法让ObjectMapper只忽略特定的注释。

Answer 2

要忽略 all 批注，Jackson版本2.x中的语法为：

objectMapper.configure(MapperFeature.USE_ANNOTATIONS, false)

使用这种方法似乎无法忽略子集。

但是可以在以下答案中找到更好的解决方案：https://stackoverflow.com/a/55064740/3351474

您的需求应该是

public class IgnoreJacksonPropertyName extends JacksonAnnotationIntrospector {

    @Override
    public PropertyName findNameForSerialization(Annotated a) {
        return PropertyName.USE_DEFAULT;
    }

    @Override
    public PropertyName findNameForDeserialization(Annotated a) {
        return PropertyName.USE_DEFAULT;
    }
}

...

mapper.setAnnotationIntrospector(new IgnoreJacksonPropertyName());

Jackson对象映射器如何忽略JsonProperty注释？

2 个答案: