How to implement the builder pattern in Java 8?

Question

Implement the builder pattern prior to Java 8 has lots of tedious, nearly duplicated code; the builder itself is typically boilerplate code. Some duplicate code detectors co

Answer 1

public class PersonBuilder {
    public String salutation;
    public String firstName;
    public String middleName;
    public String lastName;
    public String suffix;
    public Address address;
    public boolean isFemale;
    public boolean isEmployed;
    public boolean isHomewOwner;

    public PersonBuilder with(
        Consumer builderFunction) {
        builderFunction.accept(this);
        return this;
    }


    public Person createPerson() {
        return new Person(salutation, firstName, middleName,
                lastName, suffix, address, isFemale,
                isEmployed, isHomewOwner);
    }
}

Usage

Person person = new PersonBuilder()
    .with($ -> {
        $.salutation = "Mr.";
        $.firstName = "John";
        $.lastName = "Doe";
        $.isFemale = false;
    })
    .with($ -> $.isHomewOwner = true)
    .with($ -> {
        $.address =
            new PersonBuilder.AddressBuilder()
                .with($_address -> {
                    $_address.city = "Pune";
                    $_address.state = "MH";
                    $_address.pin = "411001";
                }).createAddress();
    })
    .createPerson();

Refer: https://medium.com/beingprofessional/think-functional-advanced-builder-pattern-using-lambda-284714b85ed5

Disclaimer: I am the author of the post