Java Persistence API (JPA) in Java

 Java Persistence API (JPA) in Java

JPA is a standard for object-relational mapping (ORM) in Java. It provides a set of annotations and APIs that allow you to map Java classes to database tables, and to perform database operations using Java code.

Example code:

java

@Entity

public class User {

    @Id

    private int id;

    private String name;

    private String email;

    

    // getters and setters

}

EntityManagerFactory factory = Persistence.createEntityManagerFactory("my-persistence-unit");

EntityManager em = factory.createEntityManager();

EntityTransaction tx = em.getTransaction();

tx.begin();

User user = new User();

user.setId(1);

user.setName("Alice");

user.setEmail("alice@example.com");

em.persist(user);

tx.commit();

User retrievedUser = em.find(User.class, 1);

System.out.println("Retrieved user: " + retrievedUser.getName());