Project to Implement One-To-One Mapping in JPA

package model;

import jakarta.persistence.*;

@Entity
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;

    @OneToOne(mappedBy = "person", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private Address address;

    // Constructors, getters, and setters
    public Person() {}

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }
}

package model;

import jakarta.persistence.*;

@Entity
public class Address {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "person_id")
    private Person person;

    private String city;

    // Constructors, getters, and setters
    public Address() {}

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public Person getPerson() {
        return person;
    }

    public void setPerson(Person person) {
        this.person = person;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }
}

import jakarta.persistence.*;
import model.Address;
import model.Person;

public class MainApplication {
    public static void main(String[] args) {
        // Create EntityManagerFactory
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("jpa-example");
        EntityManager em = emf.createEntityManager();

        // Begin transaction
        em.getTransaction().begin();

        // Create a person
        Person person = new Person();
        person.setName("Mahesh");
        em.persist(person);

        // Create an address
        Address address = new Address();
        address.setPerson(person);
        address.setCity("Hyderabad");
        em.persist(address);

        // Commit transaction
        em.getTransaction().commit();

        // Retrieve person and address
        Person retrievedPerson = em.find(Person.class, person.getId());

        // Check if person and associated address exist
        if (retrievedPerson != null && retrievedPerson.getAddress() != null) {
            Address retrievedAddress = retrievedPerson.getAddress();
            System.out.println("Person: " + retrievedPerson.getName());
            System.out.println("Address: " + retrievedAddress.getCity());
        } else {
            System.out.println("Person or associated Address not found.");
        }

        // Close EntityManager
        em.close();
        emf.close();
    }
}