Jackson Java to JSON object mapper modifies field's name

Question

Using Jackson to convert a Java object to JSON

ObjectMapper mapper = new ObjectMapper();
mapper.setSerializationInclusion(Include.NON_NULL);
jsonMessage = mapper.writeValueAsString(object);

the result is that the field "participants" (which is part of the object instance)

participants    Arrays$ArrayList<E> 

gets renamed to "participantsList"

participantsList":[{"userId":"c1f9c"}]

i.e. "List" is appended to the field name. I went through the Jackson documentation but haven't found a way to prevent this from happening. Is this possible? Testing the above code in a standalone project does not cause the same result (i.e. no renaming takes place). Why is Jackson behaving like this? Unfortunately, the object is third party and I cannot change it.

Using Jackson version 2.3.3 (same behaviour verified with 2.9.0).

Answer 1

Oleksandr的评论指出了正确的方向。确实，杰克逊在确定JSON字段名称时似乎考虑了一个getParticipantsList（）。但是，正如我之前所写，我无法在那里进行任何更改，因为它是第三方对象。

但是，通过更好地了解导致问题的原因，我能够找到解决方案：

mapper.setVisibilityChecker(mapper.getVisibilityChecker().withFieldVisibility(Visibility.ANY).withGetterVisibility(Visibility.NONE).withIsGetterVisibility(Visibility.NONE));

或

mapper.setVisibility(PropertyAccessor.FIELD, Visibility.ANY);
mapper.setVisibility(PropertyAccessor.GETTER, Visibility.NONE);
mapper.setVisibility(PropertyAccessor.IS_GETTER, Visibility.NONE);

Answer 2

也许您可以使用USE_ANNOTATIONS跳过这样的注释：

    ObjectMapper mapper = new ObjectMapper();
    mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
    mapper.configure(MapperFeature.USE_ANNOTATIONS, false);
    String jsonMessage = mapper.writeValueAsString(object);