Resource don't work fine

[viajero]

Y have a problem with this Code

@Stateless
@Name("reporte")
public class ReporteBean implements Reporte{

        @Logger
        Log log;

        @In
        Identity identity;
        
        @Resource(mappedName = Constantes.DATA_SOURCE)
        protected DataSource dataSource;
        
        public ReporteBean() {
        }
        
        public void crearArchivo() {

                Connection conn = null;
                
                try {
                        conn = dataSource.getConnection();
                } catch (Exception e) {
                        log.error(" ================= ERROR en ReporteBean.crearPdf ", e);
                } finally {
                        try {
                                if (conn != null) conn.close();
                        } catch (SQLException sqle) {
                                log.error(" ========================= ERROR AL CERRAR LA CONNECCION CON LA BASE DE DATOS ReporteBean.crearPdf ", sqle);
                        }
                }
        }
}

When I Call Method crearArchivo() from regionList y have a NullPointerException in this line: conn = dataSource.getConnection(); but I have another Class like This

@Stateless
@Name("reportesFt")
public class ReportesFtBean extends ReporteBean implements ReportesFt {

        public ReportesFtBean() {
        }
        
        @Override
        public void listadoRegiones() {
                this.crearArchivo();
        }
...
 

And When i call method from listadoRegiones() it works fine, somebody may explain me where is the error, I would call method from regionList(), because I need make more reports.

thanks in advance for your help.