Multiple Returns Pattern Builder

Question

I have a class Builder who is responsible for returning an object he builds:

public class ObjetoBuilder {

    private Objeto objeto; 

    public ObjetoBuilder() {
        objeto = new Objeto();
    }

    public ObjetoBuilder adicionarId(Long id) {
        if (id != null) objeto.setId(id);
        return this;
    }

    public Objeto constroi() {
        return objeto;
    }
}

Doubt

It is good practice to have more than one method builds into one Builder? For example:

public class ObjetoBuilder {
    ...
    public Objeto controi() {
        return objeto;
    }

    public List<Objeto> constroiLista(){
        return Arrays.asList(objeto);
    }

    public String constroiJson() {
        return new Gson().toJson(objeto);
    }

    public String controiXml() {
        return new XStream().toXML(objeto);
    }
}

Answer 1

The methods constroiJson, constroiLista and constroiXml of your class ObjetoBuilder do not build class objects Objeto, logo are not part of the Design Pattern. They could be part of the class Objeto, because they only convert the object into String in different formats (or in a list, in the case of constroiLista).

You can also use a helper class, which deals with converting not only to class objects Objeto, but something genetic for any class (avoiding code duplication). I particularly like this option better.