Should I use primitive data types or wrapper data types in Builder Pattern

Question

Is it better to use wrapper classes data type for the parameters in the builder pattern and then transform to primitive during build method to its primitive data type or is it better to use primitive data types throughout the builder pattern and do all data transformation of nullable data types in the controllers or the methods that calls the builder pattern?

   public Builder recent(final Boolean recent) {
        if (recent != null) {
            this.recent = recent;
        }
        return this;
    }

vs

    public Builder recent(final boolean recent) {
        this.recent = recent;
        return this;
    }

Answer 1

It depends on whether a null value is valid.

Your two examples have slightly different semantics.

public Builder recent(final Boolean recent) {
        if (recent != null) {
            this.recent = recent;
        }
        return this;
    }

The above is essentially saying that this.recent could actually hold a null value (if its type is Boolean too), but once it gets set to a non-null value, it never goes back, even if the caller requires it and passes null (is it something you want)?

public Builder recent(final boolean recent) {
        this.recent = recent;
        return this;
    }

This is saying that recent can either be set to true or false. The caller will not be misguided into thinking he can set it back to null if this.recent is actually of type Boolean. If you have a sensible default, you would even opt to set this.recent to that default directly, minimising the chance of doing a mistake somewhere else getting a NullPointerException.