How to Optimize Java Connection with Postgres

Question

My connection class with the database is taking too long to open the connection, it takes almost 20 seconds. Hibernate Usage and the Bank is Postgres running localhost.

Am I doing something wrong? or can you optimize and open faster?

My class:

  public class Connection {

    private static final String UNIT_NAME = "NameConection";
    private EntityManagerFactory emf = null;
    private EntityManager em = null;
    public EntityManager getEntityManager() {
        if (emf == null) {
            Map<String, String> map = new HashMap<String, String>();
            String user = ConfiguracoesFile.getInstancia().getUsuario();
            String pass = ConfiguracoesFile.getInstancia().getSenha();
            String banco = ConfiguracoesFile.getInstancia().getBanco();
            String server = ConfiguracoesFile.getInstancia().getServidor();
            String porta = ConfiguracoesFile.getInstancia().getPorta();
            map.put("hibernate.connection.password", pass);
            map.put("hibernate.connection.username", user);
            map.put("hibernate.connection.url", "jdbc:postgresql://" + server + ":" + porta + "/" + banco);
            emf = Persistence.createEntityManagerFactory(UNIT_NAME, map);
        }
        return em;
    }

}

It is normal to take about 20 seconds to open on localhost?

EDIT:

I managed to improve a little the loading time using the properties

<property name="hibernate.temp.use_jdbc_metadata_defaults" value="false" />
  <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>

But it’s still taking almost 10 seconds to open the connection.

Is there any other property that may be incorrect and why it is taking long?