Pasos para crear Hibernate

Crear un proyecto Maven

Escogemos maven-archetype-quickstart
En principio el de org.apache

Añadimos las dependencias de ‘Hibernate’ y ‘Mysql’. Os las pongo aquí.

 <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>8.0.32</version>
		</dependency>
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-core</artifactId>
			<version>5.6.15.Final</version>
		</dependency>
  </dependencies>

Después dentro de src/main creamos la carpeta ‘resources’: New folder

Dentro de resources creamos el archivo hibernate.cfg.xml, y dentro colocamos lo siguiente:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "https://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory>
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.url">jdbc:mysql://localhost/sakila</property>
		<property name="connection.username">root</property>
		<property name="connection.password">root</property>
		<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
		<property name="hibernate.show_sql">true</property>

		<mapping class="com.trifulcas.models.Actor" />
	
	</session-factory>
</hibernate-configuration>

Creamos un paquete com.trifulcas.models y dentro metemos nuestro POJO:

package com.trifulcas.models;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;


@Entity  
@Table(name= "actor")   
public class Actor {

	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	private int actor_id;
	
	private String first_name;
	private String last_name;
	
	public Actor() {
		
	}
	/**
	 * @return the actor_id
	 */
	public int getActor_id() {
		return actor_id;
	}
	/**
	 * @param actor_id the actor_id to set
	 */
	public void setActor_id(int actor_id) {
		this.actor_id = actor_id;
	}
	/**
	 * @return the first_name
	 */
	public String getFirst_name() {
		return first_name;
	}
	/**
	 * @param first_name the first_name to set
	 */
	public void setFirst_name(String first_name) {
		this.first_name = first_name;
	}
	/**
	 * @return the last_name
	 */
	public String getLast_name() {
		return last_name;
	}
	/**
	 * @param last_name the last_name to set
	 */
	public void setLast_name(String last_name) {
		this.last_name = last_name;
	}
	@Override
	public String toString() {
	return "Actor id=" + actor_id + ",nombre=" + first_name+" "+last_name + "]";
	}
}

Y por último probaríamos que todo va bien, este código debería funcionar:

	StandardServiceRegistry ssr = new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build();
		Metadata meta = new MetadataSources(ssr).getMetadataBuilder().build();

		SessionFactory factory = meta.getSessionFactoryBuilder().build();
		Session session = factory.openSession();
		try {
			Actor penelope = session.get(Actor.class, 1);
			
			System.out.println(penelope.getFirst_name() + " " + penelope.getLast_name());
			List<Actor> lista = session.createQuery("from Actor a where a.first_name like '%ar%' ").getResultList();
			for (Actor a : lista) {
				System.out.println(a);
			}
			
			
		} catch (Exception ex) {
			System.out.println(ex);
		}
		factory.close();
		session.close();