How to improve the builder pattern?

Question

Motivation

Recently I searched for a way to initialize a complex object without passing a lot of parameter to the constructor. I tried it with the builder pattern,

Answer 1

public class Complex {
    private final String first;
    private final String second;
    private final String third;

    public static class False {}
    public static class True {}

    public static class Builder {
        private String first;
        private String second;
        private String third;

        private Builder() {}

        public static Builder create() {
            return new Builder<>();
        }

        public Builder setFirst(String first) {
            this.first = first;
            return (Builder)this;
        }

        public Builder setSecond(String second) {
            this.second = second;
            return (Builder)this;
        }

        public Builder setThird(String third) {
            this.third = third;
            return (Builder)this;
        }
    }

    public Complex(Builder builder) {
        first = builder.first;
        second = builder.second;
        third = builder.third;
    }

    public static void test() {
        // Compile Error!
        Complex c1 = new Complex(Complex.Builder.create().setFirst("1").setSecond("2"));

        // Compile Error!
        Complex c2 = new Complex(Complex.Builder.create().setFirst("1").setThird("3"));

        // Works!, all params supplied.
        Complex c3 = new Complex(Complex.Builder.create().setFirst("1").setSecond("2").setThird("3"));
    }
}