全球忽略杰克逊的课程 [英] Globally ignore class in Jackson

问题描述

Jackson能够使用 DeserializationFeature 全局跳过未知属性，但是我找不到任何全局配置来忽略整个类的解析.我有两个具有相同名称但具有不同参数的方法的类，因此我想将此类设置为全局可忽略的(使用objectMapper对象)，而不仅仅是在模型类中添加任何注释.可能有人遇到这样的问题.

Jackson has ability to skip unknow properties globally using DeserializationFeature, but I can't find any global config to ignore whole class from being parsed. I have class with two methods with the same name but with different arguments, so I want to set this class as ignorable globally(using objectMapper object) not just by adding any annotations to model class. May be someone faced with such problem.

对不起，英语不好.

推荐答案

一个选项是使用@JsonIgnoreType注释标记要忽略的类型.如果您不想让Jackson注释弄乱模型，可以使用混合插件.

One option is to mark the type you wish to ignore with @JsonIgnoreType annotation. If you don't want to mess your model with Jackson annotations you can use mix-ins.

另一种选择是覆盖 Jackson注释内省器，以根据其类型忽略该属性.

Another option is to override the Jackson annotation introspector to ignore the property based on its type.

以下示例显示了这两个示例:

Here is example shows both:

public class JacksonIgnoreByType {
    public static final String JSON = "{\n" +
            "  \"bean1\" : {\n" +
            "    \"field1\" : \"value1\"\n" +
            "  },\n" +
            "  \"bean2\" : {\n" +
            "    \"field2\" : \"value2\"\n" +
            "  },\n" +
            "  \"bean3\" : {\n" +
            "    \"field3\" : \"value3\"\n" +
            "  }\n" +
            "}\n";

    public static class Bean1 {
        public String field1;

        @Override
        public String toString() {
            return "Bean1{" +
                    "field1='" + field1 + '\'' +
                    '}';
        }
    }

    @JsonIgnoreType
    public static class Bean2 {
        public String field2;
    }

    public static class Bean3 {
        public String field3;
    }

    public static class Bean4 {
        public Bean1 bean1;
        public Bean2 bean2;
        public Bean3 bean3;

        @Override
        public String toString() {
            return "Bean4{" +
                    "bean1=" + bean1 +
                    ", bean2=" + bean2 +
                    ", bean3=" + bean3 +
                    '}';
        }
    }

    public static void main(String[] args) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setAnnotationIntrospector(new JacksonAnnotationIntrospector(){
            @Override
            public boolean hasIgnoreMarker(AnnotatedMember m) {
                return m.getRawType() == Bean3.class || super.hasIgnoreMarker(m);
            }
        });

        System.out.println(mapper.readValue(JSON, Bean4.class));
    }
}

输出:

Bean4{bean1=Bean1{field1='value1'}, bean2=null, bean3=null}

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