// Create a new workbook Workbook workbook = new Workbook(); workbook.open(this.getResourceStream("xlsx/PageSetup Demo.xlsx")); IWorksheet worksheet = workbook.getWorksheets().get(0); //Set page orientation, default is portrait. worksheet.getPageSetup().setOrientation(PageOrientation.Landscape); // Save to an excel file workbook.save("ConfigPageOrientation.xlsx");