poi导出excel表

最近在帮人家做一个查询的功能，需要用到poi导出excel表格，之前一直也没有用过，不知道是什么情况，后来在网上找了些资料看下，也就那么一回事。希望可以给大家一些思路吧。

首先是创建一个sheet，然后再往里面添加单元格，如果手动输出过表格的话，原理其实是差不多的。

 
 /**         
      
      * 导出excel表         
      
      * @throws IOException          
      
      */        
      
     public void showExcel() throws IOException {         
      
         String [] headers= {"设备编码","设备种类","设备名称","所属总站","品牌","规格型号","提供商","设备价格","用途","出厂编号","责任人","生产日期","采购日期","启用日期","建档日期","保修日期","报废期至","备注"};         
      
         String fileName = exportExcels(headers, ServletActionContext.getRequest());         
      
         HttpServletResponse response=ServletActionContext.getResponse();         
      
         response.setContentType("application/vnd.ms-excel; charset=utf-8");         
      
         response.setHeader("Content-Disposition", "p_w_upload;filename="+fileName);         
      
         byte[] buffered = new byte[1024];         
      
         BufferedInputStream input = new BufferedInputStream(new FileInputStream(ServletActionContext.getRequest().getRealPath("/export")+"/"+fileName));         
      
         DataOutputStream output = new DataOutputStream(response.getOutputStream());         
      
         while (input.read(buffered,0,buffered.length) != -1) {         
      
             output.write(buffered,0,buffered.length);         
      
         }         
      
         input.close();         
      
         output.close();         
      
     }         
          
     /**         
      
      * 创建行         
      
      * @param cells         
      
      * @param rowIndex         
      
      * @param demoSheet         
      
      */        
      
     public static void createTableRow(List<String> cells, short rowIndex, HSSFSheet demoSheet) {         
      
         // 创建第rowIndex行         
      
         HSSFRow row = demoSheet.createRow((short) rowIndex);         
      
         for (short i = 0; i < cells.size(); i++) {         
      
             // 创建第i个单元格         
      
             HSSFCell cell = row.createCell((short) i);         
      
             cell.setCellValue(cells.get(i));         
      
         }         
      
     }         
      
     /**         
      
      * 创建sheet         
      
      * @param tableHeader         
      
      * @return         
      
      */        
      
     public  HSSFSheet createExcelSheet(String [] tableHeader,HSSFWorkbook demoWorkBook) {         
      
         List<Device> devices=deviceService.findAllDevices();         
      
         HSSFSheet demoSheet = demoWorkBook.createSheet("devices");         
      
         HSSFHeader header = demoSheet.getHeader();         
      
         header.setCenter("全部设备表");         
      
         HSSFRow headerRow = demoSheet.createRow((short) 0);         
      
         for (int i = 0; i < tableHeader.length; i++) {         
      
             HSSFCell headerCell = headerRow.createCell((short) i);         
      
             headerCell.setCellValue(tableHeader[i]);         
      
         }         
      
         for (int j = 1; j < devices.size(); j++) {         
      
             List<String> list = new ArrayList<String>();         
      
             list.add(devices.get(j).getDev_no()!=null?devices.get(j).getDev_no():"");         
      
             list.add(devices.get(j).getCategory().getCat_name()!=null?devices.get(j).getCategory().getCat_name():"");         
      
             list.add(devices.get(j).getDev_name()!=null?devices.get(j).getDev_name():"");         
      
             list.add(devices.get(j).getDepartment().getDep_name()!=null?devices.get(j).getDepartment().getDep_name():"");         
      
             list.add(devices.get(j).getDev_brand()!=null?devices.get(j).getDev_brand():"");         
      
             list.add(devices.get(j).getDev_spec()!=null?devices.get(j).getDev_spec():"");         
      
             list.add(String.valueOf(devices.get(j).getDev_fac())!=null?String.valueOf(devices.get(j).getDev_fac()):"");         
      
             list.add(String.valueOf(devices.get(j).getDev_price())!=null?String.valueOf(devices.get(j).getDev_price()):"");         
      
             list.add(devices.get(j).getDev_purpose()!=null?devices.get(j).getDev_purpose():"");         
      
             list.add(devices.get(j).getDev_bookid()!=null?devices.get(j).getDev_bookid():"");         
      
             list.add(devices.get(j).getUser().getUser_name()!=null?devices.get(j).getUser().getUser_name():"");//责任人         
      
             list.add(devices.get(j).getDev_protime()!=null?devices.get(j).getDev_protime():"");         
      
             list.add(devices.get(j).getDev_booktime()!=null?devices.get(j).getDev_booktime():"");         
      
             list.add(devices.get(j).getDev_usetime()!=null?devices.get(j).getDev_usetime():"");         
      
             list.add(devices.get(j).getDev_settime()!=null?devices.get(j).getDev_settime():"");         
      
             list.add(devices.get(j).getDev_retime()!=null?devices.get(j).getDev_retime():"");         
      
             list.add(devices.get(j).getDev_dumptime()!=null?devices.get(j).getDev_dumptime():"");         
      
             list.add(devices.get(j).getDev_remark()!=null?devices.get(j).getDev_remark():"");         
      
             createTableRow(list, (short) j,demoSheet);         
      
         }         
      
         return demoSheet;         
      
     }         
          
     /**         
      
      * 输出         
      
      * @param os         
      
      * @param tableHeader         
      
      * @throws IOException         
      
      */        
      
     public void exportExcel(OutputStream os,String [] tableHeader,HSSFWorkbook demoWorkBook) throws IOException {         
      
         HSSFSheet sheet = createExcelSheet(tableHeader,demoWorkBook);         
      
         sheet.setGridsPrinted(true);         
      
         HSSFFooter footer = sheet.getFooter();         
      
         footer.setRight("Page " + HSSFFooter.page() + " of " + HSSFFooter.numPages());         
      
         demoWorkBook.write(os);         
      
     }         
          
      public  String exportExcels(String[] tableHeader,HttpServletRequest request) {         
      
          HSSFWorkbook demoWorkBook = new HSSFWorkbook();         
      
          //SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss");         
      
         String fileName="devicess.xls";         
      
         request=ServletActionContext.getRequest();         
      
         FileOutputStream fos = null;         
      
         try {         
      
             fos = new FileOutputStream(request.getRealPath("/export")+"/"+fileName);         
      
             exportExcel(fos,tableHeader,demoWorkBook);         
      
         } catch (Exception e) {         
      
             e.printStackTrace();         
      
         } finally {         
      
             try {         
      
                 fos.close();         
      
             } catch (Exception e) {         
      
                 e.printStackTrace();         
      
             }         
      
         }         
          
         return fileName;         
      
     }