Jackson change the key of a value without using annotation

Question

I have a class A, with a property Pojo p .

class A {
   Pojo p;
}

I have a custom Serializer for Pojo, but I didn't find any way to change the key of Pojo, by default it's serialized as p .

Is there any way to change the key p to something else, like

{
"some_other_key": {/* json for Pojo goes here*/}  
}

I can't use jackson annotations because this is a class from a lib.

public class PojoSerializer extends StdSerializer<Pojo> {


  @Override
  public void serialize(Pojo pojo, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
    //how can I set the key of this Pojo?
    jsonGenerator.writeObject(pojo);
  }

}

Answer 1

In a nutshell, use jsonGenerator.

jsonGenerator.writeStartObject();
jsonGenerator.writeNumberField("firstField", pojo.getFirstField());
jsonGenerator.writeEndObject();

You also need a custom serializer for A itself, not just "Pojo".

public class PojoSerializer extends StdSerializer<A> {


  public SaleBoSerializer(Class<A> t) {
    super(t);
  }

  @Override
  public void serialize(A a, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
    jsonGenerator.writeStartObject();
    jsonGenerator.writeObjectField("custom_field_name", a.pojo)
    jsonGenerator.writeEndObject();
  }

}