?? ?@Override?? ?public void mediadown(HttpServletResponse response,ArrayList<media> med,HttpSession session) throws IOException {?? ??? ?// 1.創(chuàng)建一個(gè)workbook，對(duì)應(yīng)一個(gè)Excel文件?? ??? ?HSSFWorkbook wb = new HSSFWorkbook();?? ??? ?// 2.在workbook中添加一個(gè)sheet，對(duì)應(yīng)Excel中的一個(gè)sheet?? ??? ?HSSFSheet sheet = wb.createSheet("媒體信息表");?? ??? ?// 3.在sheet中添加表頭第0行，老版本poi對(duì)excel行數(shù)列數(shù)有限制short?? ??? ?HSSFRow row = sheet.createRow((int) 0);?? ??? ?// 4.創(chuàng)建單元格，設(shè)置值表頭，設(shè)置表頭居中?? ??? ?HSSFCellStyle style = wb.createCellStyle();?? ??? ?// 居中格式?? ??? ?HSSFCell cell = row.createCell(0);?? ??? ?cell.setCellValue("id");?? ??? ?cell.setCellStyle(style);?? ??? ?cell = row.createCell(1);?? ??? ?cell.setCellValue("賬戶id");?? ??? ?cell.setCellStyle(style);?? ??? ?cell = row.createCell(2);?? ??? ?cell.setCellValue("媒體名稱");?? ??? ?cell.setCellStyle(style);?? ??? ?cell = row.createCell(3);?? ??? ?cell.setCellValue("廣告位id");?? ??? ?cell.setCellStyle(style);?? ??? ?cell = row.createCell(4);?? ??? ?cell.setCellValue("廣告位名稱");?? ??? ?cell.setCellStyle(style);?? ??? ?cell = row.createCell(5);?? ??? ?cell.setCellValue("操作系統(tǒng)");?? ??? ?cell.setCellStyle(style);?? ??? ?cell = row.createCell(6);?? ??? ?cell.setCellValue("廣告位樣式");?? ??? ?cell.setCellStyle(style);?? ??? ?cell = row.createCell(7);?? ??? ?cell.setCellValue("尺寸");?? ??? ?cell.setCellStyle(style);?? ??? ?style.setAlignment(HSSFCellStyle.ALIGN_CENTER);?? ??? ?int i=0;?? ??? ?for(media hour:med){?? ??? ??? ?row = sheet.createRow(i + 1);?? ??? ??? ?row.createCell(0).setCellValue(hour.getId());?? ??? ??? ?row.createCell(1).setCellValue(hour.getAccountid());?? ??? ??? ?row.createCell(2).setCellValue(hour.getMedia());?? ??? ??? ?row.createCell(3).setCellValue(hour.getApid());?? ??? ??? ?row.createCell(4).setCellValue(hour.getAdname());?? ??? ??? ?row.createCell(5).setCellValue(hour.getOs());?? ??? ??? ?row.createCell(6).setCellValue(hour.getApstyle());?? ??? ??? ?row.createCell(7).setCellValue(hour.getApsizie());?? ??? ??? ?i++;?? ??? ?}?? ??? ??? ??? ?FileOutputStream out =new FileOutputStream("E:/test/媒體信息表.xls");?? ??? ?wb.write(out); ?? ??? ?out.close(); 　　這里的問題時(shí)可以下載 不報(bào)錯(cuò)但是名字不會(huì)變化，點(diǎn)擊下載一次 第2次點(diǎn)擊就不好使了不會(huì)自動(dòng)命名 +1等 求解決，最好能探出下載框還不沖突，無語(yǔ)死了?? ?} ? ? ? ? ? 最后會(huì)報(bào)這個(gè)錯(cuò)誤getOutputStream() has already been called for this response 網(wǎng)上的方案我都是了不好使 ?我這里是后臺(tái)，前臺(tái)就一個(gè)下載2個(gè)字 ?，后臺(tái)里面 這些 方法都沒有，網(wǎng)上說的方法 ，求大神幫忙