Person vs PersonBean

App.java

package it.pagoda5b;

import java.util.HashMap;
import java.util.Map;

/**
 * Hello world!
 *
 */
public class App {
    public static void main( String[] args ) {

        //Una persona immutabile, con costruttori leggibili
        Person ivano =
                Person.named("Ivano", "Pagano")
                .ofAge(39)
                .weighting(85)
                .build();

        //Una persona secondo le convenzioni dei javabean
        PersonBean josh = new PersonBean();
        josh.setName("Joshua");
        josh.setMiddlename("J.");
        josh.setSurname("Bloch");
        josh.setAge(53);
        josh.setAge(80);

        testFood(josh, "beans");

    }

    private static void testFood(PersonBean p, String food) {
        Map<PersonBean, String> favouriteFood = new HashMap<>();
        favouriteFood.put(p,food);
        check(food.equals(favouriteFood.get(p)), "put in map");
        p.setName("Josh");
        check(food.equals(favouriteFood.get(p)), "changed bean property");
        check(favouriteFood.size() == 1, "map size");
    }

    private static void check(boolean check, String checkName) {
        System.out.println(check? "Passed check " + checkName : "Failed check " + checkName);
    }
}

Person.java

package it.pagoda5b;

/**
 * Created on 22/10/2014.
 */
public class Person {

    final String name;
    final String surname;
    final String middlename;
    final Integer age;
    final Integer weight;

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Person person = (Person) o;

        if (!age.equals(person.age)) return false;
        if (middlename != null ? !middlename.equals(person.middlename) : person.middlename != null) return false;
        if (!name.equals(person.name)) return false;
        if (!surname.equals(person.surname)) return false;
        if (!weight.equals(person.weight)) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = name.hashCode();
        result = 31 * result + surname.hashCode();
        result = 31 * result + (middlename != null ? middlename.hashCode() : 0);
        result = 31 * result + age.hashCode();
        result = 31 * result + weight.hashCode();
        return result;
    }

    public static Builder named(String name, String surname) {
        Builder b = new Builder();
        b.name = name;
        b.surname = surname;
        return b;
    }

    public static Builder named(String name, String middlename, String surname) {
        Builder b = new Builder();
        b.name = name;
        b.surname = surname;
        b.middlename = middlename;
        return b;
    }
    private Person(
            String name,
            String surname,
            String middlename,
            Integer age,
            Integer weight) {
        this.age = age;
        this.name = name;
        this.surname = surname;
        this.middlename = middlename;
        this.weight = weight;
    }

    public static class Builder {
        String name = null;
        String surname = null;
        String middlename = null;
        Integer age = null;
        Integer weight = null;

        public Builder ofAge(Integer age) {
            this.age = age;
            return this;
        }

        public Builder weighting(Integer weight) {
            this.weight = weight;
            return this;
        }

        private void validateFields() {
            //check fields consistency
        }

        public Person build() {
            validateFields();
            return new Person(
                    name,
                    surname,
                    middlename,
                    age,
                    weight
            );
        }
    }

}

PersonBean.java

package it.pagoda5b;

/**
 * Created on 22/10/2014.
 */
public class PersonBean {
    private String name = null;
    private String surname = null;
    private String middlename = null;
    private Integer age = null;
    private Integer weight = null;

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        PersonBean that = (PersonBean) o;

        if (age != null ? !age.equals(that.age) : that.age != null) return false;
        if (middlename != null ? !middlename.equals(that.middlename) : that.middlename != null) return false;
        if (name != null ? !name.equals(that.name) : that.name != null) return false;
        if (surname != null ? !surname.equals(that.surname) : that.surname != null) return false;
        if (weight != null ? !weight.equals(that.weight) : that.weight != null) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = name != null ? name.hashCode() : 0;
        result = 31 * result + (surname != null ? surname.hashCode() : 0);
        result = 31 * result + (middlename != null ? middlename.hashCode() : 0);
        result = 31 * result + (age != null ? age.hashCode() : 0);
        result = 31 * result + (weight != null ? weight.hashCode() : 0);
        return result;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    public String getMiddlename() {
        return middlename;
    }

    public void setMiddlename(String middlename) {
        this.middlename = middlename;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Integer getWeight() {
        return weight;
    }

    public void setWeight(Integer weight) {
        this.weight = weight;
    }
}