context.xml

<?xml version="1.0" encoding="UTF-8"?>

<Context antiJARLocking="true" path="/">
    <Resource
            name="jdbc/MyApp"
            auth="Container"
            type="javax.sql.DataSource"
            username="your_username"
            password="your_password"
            driverClassName="com.mysql.jdbc.Driver"
            url="jdbc:mysql://localhost:3306/db_name"
            maxActive="8"
            maxIdle="4"/>

</Context>

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>

        <property name="show_sql">true</property>
        <property name="format_sql">true</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="current_session_context_class">thread</property>
        <property name="hbm2ddl.auto">update</property>

        <property name="hibernate.max_fetch_depth">3</property>

        <property name="connection.datasource">java:comp/env/jdbc/MyApp</property>

        <!-- Mapping files -->

        <mapping class="com.playground.myapp.model.User"/>

    </session-factory>
</hibernate-configuration>

HibernateListener.java

package com.playground.myapp.web;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class HibernateListener  implements ServletContextListener {

    private SessionFactory sessionFactory;
    private static ServiceRegistry serviceRegistry;

    public void contextInitialized(ServletContextEvent sce){
        ServletContext context = sce.getServletContext();

        try{
            Configuration configuration = new Configuration();
            configuration.configure();
            serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        }catch (Throwable ex) {
            System.err.println("Failed to create sessionFactory object." + ex);
            throw new ExceptionInInitializerError(ex);
        }

        context.setAttribute("sessionFactory", sessionFactory);

    }

    public void contextDestroyed(ServletContextEvent sce) {
        sessionFactory.close();
    }
}

persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">

    <persistence-unit name="com.playground.myapp.jpa" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <non-jta-data-source>java:comp/env/jdbc/MyApp</non-jta-data-source>

        <!-- Classes -->
        <class>com.playground.myapp.model.User</class>

        <properties>

            <property name="hibernate.connection.datasource" value="java:comp/env/jdbc/MyApp"/>
            <property name="hibernate.id.new_generator_mappings" value ="true"/>

            <property name="hibernate.archive.autodetection" value="class"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="hibernate.format_sql" value="true"/>
            <property name="hibernate.hbm2ddl.auto" value="update"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
            <property name="connection.autocommit" value="false"/>

        </properties>
    </persistence-unit>
</persistence>

PersistenceListener.java

package com.playground.myapp.web;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class PersistenceListener implements ServletContextListener {


    private EntityManagerFactory entityManagerFactory;

    public void contextInitialized(ServletContextEvent sce){
        ServletContext context = sce.getServletContext();
        entityManagerFactory = Persistence.createEntityManagerFactory("com.playground.myapp.jpa");
    }

    public void contextDestroyed(ServletContextEvent sce) {
        entityManagerFactory.close();
    }
}

web.xml

<listener>
        <description>HibernateListener</description>
        <listener-class>com.playground.myapp.web.HibernateListener</listener-class>
</listener>

<resource-ref>
        <description>DB Connection</description>
        <res-ref-name>jdbc/MyApp</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
</resource-ref>