Java.Hibernate.Beginner.Can you configure Hibernate using annotations instead of XML?

Yes — Hibernate (and JPA) support annotations as a modern alternative to XML mapping files. You can map your entities, primary keys, relationships, and other metadata directly in your Java classes using standard JPA or Hibernate-specific annotations.

🔹 Key annotations you use instead of XML:

• @Entity — marks the class as a persistent entity.
• @Table — specifies the table name (optional if same as class).
• @Id — defines the primary key field.
• @GeneratedValue — configures how the primary key is generated.
• @Column — customizes column details.
• @OneToOne, @OneToMany, @ManyToOne, @ManyToMany — define relationships.
• @Embedded, @Embeddable — map embedded value types.

🔹 Example with annotations instead of XML mapping:

import javax.persistence.*;

@Entity
@Table(name = "users")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "username", nullable = false, unique = true)
    private String username;

    @Column(name = "email")
    private String email;

    // getters and setters
}

✅ Here, there’s no need for User.hbm.xml — everything is defined directly in the Java class.

🔹 How is this better than XML?
✅ Easier to read: mapping information sits right next to the fields it describes.
✅ Easier to maintain: fewer separate files to manage.
✅ Type-safe: Java compiler checks your class names and field names.
✅ Less risk of mismatches between Java code and XML mappings.

🔹 What about Hibernate configuration itself?

• While you still need some global configuration (database connection, dialect), you can use application.properties (in Spring Boot) or hibernate.cfg.xml just for settings, but the entity mappings themselves don’t need XML anymore.

✅ Key takeaway:
Yes — you can fully map your entities with annotations instead of XML, and this is the recommended, modern approach for Hibernate/JPA projects.