Builder pattern

BuilderApp.java

package com.app.designPatterns.builder1;

public class BuilderApp {

    public static void main(String[] args) {

        Phone iphone = new PhoneBuilder().setModel("Apple").setOs("IOS").buildPhone();
        System.out.println(iphone);

        Phone androidPhone = new PhoneBuilder().setModel("Nokia").setOs("Android").setCamera("32MP").buildPhone();
        System.out.println(androidPhone);
    }
}

Phone.java

package com.app.designPatterns.builder1;

public class Phone {

    private String model;
    private String os;
    private Integer price;
    private String camera;

    public Phone(String model, String os, Integer price, String camera) {
        super();
        this.model = model;
        this.os = os;
        this.price = price;
        this.camera = camera;
    }

    @Override
    public String toString() {
        return "Phone{" +
                "model='" + model + '\'' +
                ", os='" + os + '\'' +
                ", price=" + price +
                ", camera='" + camera + '\'' +
                '}';
    }
}

PhoneBuilder.java

package com.app.designPatterns.builder1;

public class PhoneBuilder {

    private String model;
    private String os;
    private Integer price;
    private String camera;

    public PhoneBuilder setModel(String model) {
        this.model = model;
        return this;
    }

    public PhoneBuilder setOs(String os) {
        this.os = os;
        return this;
    }

    public PhoneBuilder setPrice(Integer price) {
        this.price = price;
        return this;
    }

    public PhoneBuilder setCamera(String camera) {
        this.camera = camera;
        return this;
    }

    public Phone buildPhone() {
        return new Phone(model, os, price, camera);
    }
}