如何使用Jackson将POJO序列化为JSON？

Question

I have a POJO that I want to Serialize differently based on a value of one of the properties.

Say, I have the POJO below. I want to include NULLs when "show" is true, and exclude NULLS when "show" is false. Be aware that the actual Object I am trying to Serialize has over 30 properties.

public class User {
    @JsonIgnore
    private boolean show;

    private String name;
    private Integer age;
    ...
    ...
}

I would like to know how to do that using Jackson. Do I have to implement my own JsonSerializer, or should I create a PropertyFilter? Or have I missed an out of the box feature?

Answer 1

You can write your own custom serialiser that takes care of the generation of null properties based on the show instance variable. For that you can create a ObjectMapper with NULL serialisation settings based on your show property and then delegate the serialisation to it.

I have a similar requirement and probably I'll be acquainting myself with the actual APIs of Object Mapper. I'll try to post the code for the above.