Jackson ignore empty objects "{}" without custom serializer

Question

I would like to serialize to JSON a POJO containing another POJO with empty values.

For example, given:

class School {
  String name;
  Room room;
}

class Room {
  String name;
}

Room room = new Room();
School school = new School("name");
school.room = room;

After the serialisation it will look like that

{ "name": "name", "room": {}}

Is it possible to exclude the empty object {} if all the fields of the class are also empty? Ideally globally for every object without writing custom code.

Answer 1

A little bit late , add JsonInclude custom

class School {
  String name;
  @JsonInclude(value = JsonInclude.Include.CUSTOM, valueFilter = Room .class)
  Room room;
}


@EqualsAndHashCode
class Room {
      String name;
}

This will avoid to include room if is equals than new Room(). Don't forget implement equals method in Room class and include an empty constructor

Besides you can use @JsonInclude( Include.NON_EMPTY ) or @JsonInclude( Include.NON_DEFAULT ) at class level to skip possible nulls or empty values