Agregar DataSource /JNDI

Agregar DataSource a una clase desde un JNDI

fuente

Injecting datasource in EJBStack Overflow

@Resource(mappedName="jndi/yourDatasource")
DataSource ds;

..

Connection conn = null;
try {
     conn = ds.getConnection();
     //PERFORM QUERY, ETC..
}
catch(SQLException ex) {
     //EXCEPTION HANDLING
}
finally {
    try {
        if(conn != null)
            conn.close();
    }
    catch(SQLException ex) {..}
}