<?xml version="1.0" encoding="UTF-8"?>
<tomee>
  <!-- see http://tomee.apache.org/containers-and-resources.html -->

  <!-- activate next line to be able to deploy applications in apps -->
  <!-- <Deployments dir="apps" /> -->

<!-- <Resource auth="Container" driverClassName="org.postgresql.Driver" global="jdbc/MyPostgresDB" name="jdbc/MyPostgresDB" password="postgres" type="javax.sql.DataSource" url="jdbc:postgresql://127.0.0.1:5432/Hibernate" username="postgres"/> -->

<Resource id="PostgresDbDs" type="javax.sql.DataSource">
    #  PostgreSQL connection
    jdbcDriver=org.postgresql.Driver
    jdbcUrl=jdbc:postgresql://127.0.0.1:5432/Hibernate
    userName=postgres
    password=postgres
    jtaManaged=true
  </Resource>

</tomee>

Connection conn = dataSource.getConnection();
Statement st = conn.createStatement();

Cannot create JDBC driver of class '' for connect URL 'null'

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
    xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="movie-unit" transaction-type="JTA">
        <!-- <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> -->
        <jta-data-source>PostgresDbDs</jta-data-source>
        <non-jta-data-source>PostgresDbDsNotManagingBhai</non-jta-data-source>
        <class>org.ap.poc.ejb.Movie</class>
        <properties>
            <!-- <property name="eclipselink.ddl-generation" value="create-tables"
                /> <property name="eclipselink.ddl-generation.output-mode" value="database"
                /> <property name="eclipselink.logging.level" value="FINE" /> -->
        </properties>
    </persistence-unit>
</persistence>