<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">

<persistence-unit name="PERSISTENCE">
    <description> Hibernate JPA Configuration Example</description>
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
    <class>com.resourceserver.Person</class>
    <properties>
        <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" />
        <property name="javax.persistence.jdbc.url"
            value="jdbc:mysql://localhost:3306/RESTResourceServer" />
        <property name="javax.persistence.jdbc.user" value="root" />
        <property name="javax.persistence.jdbc.password" value="password" />
        <property name="hibernate.show_sql" value="true" />
        <property name="hibernate.hbm2ddl.auto" value="update" />
    </properties>
</persistence-unit>

public class PersonDao {

    EntityManager entityManager;

    public PersonDao() {
        entityManager = JPAUtil.getEntityManagerFactory().createEntityManager();
    }

    public void storePerson(Person person) {
        entityManager.persist(person);
        // people.add(person);
    }

    public void deletePerson(Person person) {
        entityManager.remove(person);
        // people.remove(person);
    }

    public Person findPersonId(int id) {
        /*
         * for (Person person : people) { if (person.getId() == id) { return person; } }
         */
        return null;
    }

    @SuppressWarnings("unchecked")
    public List<Person> getAllUsers() {
        Query query = entityManager.createQuery("Select p From People p ");
        return query.getResultList();
        // return people;
    }
}

public class JPAUtil {
    private static final String PERSISTENCE_UNIT_NAME = "PERSISTENCE";
    private static EntityManagerFactory factory;

    public static EntityManagerFactory getEntityManagerFactory() {
        if (factory == null) {
            factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
        }
        return factory;
    }

    public static void shutdown() {
        if (factory != null) {
            factory.close();
        }
    }
}