Pasos proyecto

1.- Crear proyecto Maven (maven-archetype-quickstart)
2.- Añadir dependencias: Mysql e hibernate

<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>

3.- Creo la clase HibernateUtil

package com.trifulcas.hibernate;

import java.util.Properties;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.service.ServiceRegistry;

public class HibernateUtil {
	  private static  SessionFactory sessionFactory;
	 
	    public static SessionFactory getSessionFactory() {
	    	if (sessionFactory == null) {
				try {
					Configuration configuration = new Configuration();

					// Hibernate settings equivalent to hibernate.cfg.xml's properties
					Properties settings = new Properties();
					settings.put(Environment.DRIVER, "com.mysql.cj.jdbc.Driver");
					settings.put(Environment.URL, "jdbc:mysql://localhost:3306/sakila");
					settings.put(Environment.USER, "root");
					settings.put(Environment.PASS, "");
					settings.put(Environment.DIALECT, "org.hibernate.dialect.MySQL5Dialect");

					settings.put(Environment.SHOW_SQL, "true");

					settings.put(Environment.CURRENT_SESSION_CONTEXT_CLASS, "thread");


					configuration.setProperties(settings);
					
					

					ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
							.applySettings(configuration.getProperties()).build();
					
					sessionFactory = configuration.buildSessionFactory(serviceRegistry);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			return sessionFactory;
	    }
	 
	    public static void shutdown() {
	        // Close caches and connection pools
	        getSessionFactory().close();
	    }
}

4.- Pongo los datos correctos de conexión: BD, usuario y password (settings.put(Environment.URL, “jdbc:mysql://localhost:3306/biblioteca”);)
5.- Creo mi entidad

package com.trifulcas.models;

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

@Entity
@Table(name = "genero")
public class Genero {

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "idgenero")
	private int idGenero;

	private String nombre;

	public Genero() {
		super();
		// TODO Auto-generated constructor stub
	}

	public int getIdGenero() {
		return idGenero;
	}

	public void setIdGenero(int idGenero) {
		this.idGenero = idGenero;
	}

	public String getNombre() {
		return nombre;
	}

	public void setNombre(String nombre) {
		this.nombre = nombre;
	}

	@Override
	public String toString() {
		return "Genero [idGenero=" + idGenero + ", nombre=" + nombre + "]";
	}

	
}

6.- Lo anotamos en hibernateutil

...
				configuration.addAnnotatedClass(Genero.class);
...

7.- Lo pruebo:

Session session = HibernateUtil.getSessionFactory().openSession();
		try {
			Genero g = session.get(Genero.class, 1);
			System.out.println(g);
		} catch (Exception ex) {
			System.out.println(ex);
		}
		session.close();