How to avoid duplicating JSON field when serializing two fields in one custom Jackson JsonSerializer?

Question

Main Goal:

I would like to serialize 2 POJO fields from within 1 field's CustomSerializer while avoiding the default serialization of the second field and keeping the POJO as clean as possible.

POJO:

public class Entity{

    // The existence of @JsonProperty on either fields does not change the behavior.
    
    @JsonSerialize(using=MySerializer.class)
    @HashTo("hashedKuku")
    private String kuku;

    private String hashedKuku;

    // Public Getters & Setters for both fields

}

MySerializer:

public class MySerializer extends JsonSerializer<String> {

    // Some code including try-catch clauses omitted for simplicity.

    @Override
    public void serialize(String value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        gen.writeString(value);
        final String currentFieldName = gen.getOutputContext().getCurrentName();
        final Field declaredField = gen.getCurrentValue().getClass().getDeclaredField(currentFieldName);
        final HashTo annotation = declaredField.getAnnotation(HashTo.class);
        final String hashFieldName;
        if(annotation!=null && !(hashFieldName=annotation.value()).isEmpty()) {
            // gen.writeStringField(hashFieldName, new Hasher().getHashedValue(value));
            // OR
            serializers.defaultSerializeField(hashFieldName, new Hasher().getHashedValue(value), gen);              
    }

}

Expected Result:

{
    "kuku": "someValue",
    "hashedKuku": "someHash"
}

Actual Result:

{
    "kuku": "someValue",
    "hashedKuku": "someHash",
    "hashedKuku": null
}

The Problem:

MySerializer does the job, and the defualt serializer serializes hashedKuku as well.

Constraints:

• MySeializer should be on the field itself and not a class-level serializer.
• Keep the POJO as clean as possible (have only 2 annotations on kuku field).

What I've Tried: (Solutions that work but are not good enough)

1. Using JsonProperty.Access.WRITE_ONLY:

  @JsonProperty(JsonProperty.Access.WRITE_ONLY)
  private String hashedKuku;

2. Using @JsonIgnore on the field:

  @JsonIgnore
  private String hashedKuku;

3. Using @JsonIgnore on the getter:

  @JsonIgnore
  public String getHashedKuku() {
    return hashedKuku;
  }

4. Many more solutions that I will skip as they're either an overengineering or also not good enough.

Ultimate Solution:

Register the serialization of hashedKuku so the default serializer skips it.
Maybe get access to the default serializer in MySerializer and serialize hashedKuku through it?

What I've Researched:

• Jackson add custom field with hash of another field - Not good as I have the field in the POJO.
• Jackson: How to add custom property to the JSON without modifying the POJO - Same as first.
• Jackson add custom field with hash of another field - I do not understand the usage of BeanSerializerModifier or how to register it in a Spring application.
• How to add a new Property with BeanSerializerModifier's changeProperties?
• How to access default jackson serialization in a custom serializer with the same object - Class-level serializer.
• Jackson Custom Serializer shows the same context for 2 different field during the Json Serialization
• Jackson - custom serializer that overrides only specific fields
• How to access default jackson serialization in a custom serializer - Class-level serializer.
• Jackson custom serializer serialize field twice if property name not equal field name
• Apply default serializer to properties in custom serializer with Jackson
• Duplicate JSON Field with Jackson - Not same case.
• Jackson: How to edit existing property to the JSON without modifying the POJO?