如何使 Jackson SimpleBeanPropertyFilter filterOutAllExcept 适用于嵌套对象

Question

如何保持所有嵌套对象具有相同的属性名称？ 例如。顶级课程是政策。

@JsonFilter("myFilter")
public class Policy {
    String name;
    String number;
    List<Participant> participants;
    List<Asset> assets;
    Map<String, String> additionalFields;
}

@JsonFilter("myFilter")
public class Participant {
    String name;
    String number;
    List<Asset> assets;
    Map<String, String> additionalFields;
}

@JsonFilter("myFilter")
public class Asset {
    String name;
    String number;
    Map<String, String> additionalFields;
}

现在，我想排除响应中所有对象上除 extraFields 之外的所有字段。我有以下实现，但这会删除所有内容，只保留策略上的附加字段。

SimpleFilterProvider filterProvider = new SimpleFilterProvider() .addFilter("myFilter", SimpleBeanPropertyFilter.filterOutAllExcept("additionalFields"));

Answer 1

你描述的情况，如果不包括其他依赖，它实际上是2个过滤器来实现你的目标（因为你的使用行为是从上到下的过滤器，并用属性名称来判断）。例如

@JsonFilter("policyFilter")
public class Policy {
    String name;
    String number;
    List<Participant> participants;
    List<Asset> assets;
    Map<String, String> additionalFields;
}

@JsonFilter("myFilter")
public class Participant {
    String name;
    String number;
    List<Asset> assets;
    Map<String, String> additionalFields;
}

@JsonFilter("myFilter")
public class Asset {
    String name;
    String number;
    Map<String, String> additionalFields;
}


PropertyFilter policyFilter=  SimpleBeanPropertyFilter.filterOutAllExcept("additionalFields","participants","assets");
PropertyFilter myFilter =  SimpleBeanPropertyFilter.filterOutAllExcept("additionalFields");
SimpleFilterProvider filterProvider = new SimpleFilterProvider() .addFilter("myFilter", myFilter );

如果你想使用一个过滤器来控制序列化，jackson标准过滤器不支持这样的嵌套属性，https://github.com/FasterXML/jackson-databind/issues/1040中有一些讨论。 但存在一些社区解决方案。你可以使用它们

https://github.com/krishna81m/jackson-nested-prop-filter

如果您使用上面的解决方案，代码应该是

@JsonFilter("myFilter")
public class Policy {
    String name;
    String number;
    List<Participant> participants;
    List<Asset> assets;
    Map<String, String> additionalFields;
}

// @JsonFilter("myFilter")
public class Participant {
    String name;
    String number;
    List<Asset> assets;
    Map<String, String> additionalFields;
}

// @JsonFilter("myFilter") there is no need to specific such config,access graph already in NestedPropertyFilterProvider
public class Asset {
    String name;
    String number;
    Map<String, String> additionalFields;
}

        FilterProvider filterProvider =  new NestedPropertyFilterProvider()
                .addFilter("myFilter",
                        NestedBeanPropertyFilter.filterOutAllExcept(Policy.class,
                                "additionalFields",
                                "participants.additionalFields", // nest property
                                "assets.additionalFields")); // nest property