POI java reader for Excel doesn't take the first sheet -

im trying take first sheet , put linkedlist, doesnt take first sheet, starts number one, , counter started zero. have been trying other kind of things, sheet 0 full.

    public void leer_archivo(string ruta)throws ioexception{          fileinputstream file = new fileinputstream(new file (ruta));          xssfworkbook workbook = new xssfworkbook(file);         (int = 0; < 5; i++){         system.out.println(i);         xssfsheet sheet = workbook.getsheetat(i);          iterator<row> rowiterator = sheet.iterator();         row row;          while (rowiterator.hasnext()){             row = rowiterator.next();              iterator<cell> celliterator = row.celliterator();             cell celda;              while (celliterator.hasnext()){                 celda = celliterator.next();                  switch(celda.getcelltype()) {                     case cell.cell_type_numeric:                         if( hssfdateutil.iscelldateformatted(celda) ){                              system.out.println(celda.getdatecellvalue());          }else{          //   system.out.println(celda.getnumericcellvalue());                 //cuando cae aqui repite los valores de la celda           }                      valorcelda = (int) celda.getnumericcellvalue();                  agregar_valor( valorcelda, i);           break;                   case cell.cell_type_string:                      nombrecelda = celda.getstringcellvalue();                     agregar_equipo(nombrecelda, i);                     system.out.println(i + "hola");           break;        }       }    }  workbook.close();  }  }