今天在pdf和excel中都实现了在浏览器弹出下载框
将之前在网上查找的生成excel表格代码稍微修改下：
public class CreateSimpleExcelToDisk { /** * @功能：手工构建一个简单格式的Excel */ private static List<News> getNews() throws Exception { List<News> data = new ArrayList<News>(); NewsDao dao = new NewsDao(); ArrayList<News> list=dao.queryAll(); SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd"); for(News news:list){ // News user1 = new News(news.getNewsId(),news.getTypeId(), news.getTitle(), news.getPublishTime(), news.getBody(),news.getTag(),news.getAuthor(),news.getClicks(),news.getImgUrl()); data.add(new News(news.getNewsId(),news.getTypeId(), news.getTitle(), news.getPublishTime(), news.getBody(),news.getTag(),news.getAuthor(),news.getClicks(),news.getImgUrl())); } return list; } public void ExpExcel(OutputStream out) throws Exception{ // 第一步，创建一个webbook，对应一个Excel文件 HSSFWorkbook wb = new HSSFWorkbook(); // 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet HSSFSheet sheet = wb.createSheet("Sheet1"); // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short HSSFRow row = sheet.createRow((int) 0); // 第四步，创建单元格，并设置值表头 设置表头居中 HSSFCellStyle style = wb.createCellStyle(); style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式 HSSFCell cell = row.createCell((short) 0); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("newsid"); cell.setCellStyle(style); cell = row.createCell((short) 1); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("typeid"); cell.setCellStyle(style); cell = row.createCell((short) 2); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("title"); HSSFCellStyle style2 = wb.createCellStyle(); style2.setAlignment(HSSFCellStyle.ALIGN_LEFT); // 创建一个居左格式 cell.setCellStyle(style2); cell = row.createCell((short) 3); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("publishtime"); cell.setCellStyle(style); cell = row.createCell((short) 4); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("body"); cell.setCellStyle(style); cell = row.createCell((short) 5); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("tag"); cell.setCellStyle(style); cell = row.createCell((short) 6); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("author"); cell.setCellStyle(style); cell = row.createCell((short) 7); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("clicks"); cell.setCellStyle(style); cell = row.createCell((short) 8); // 设置编码格式主要是解决导出中文等的乱码 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue("imgUrl"); cell.setCellStyle(style); // 第五步，写入实体数据 实际应用中这些数据从数据库得到， List list = CreateSimpleExcelToDisk.getNews(); for (int i = 0; i < list.size(); i++) { row = sheet.createRow((int) i + 1); News news = (News) list.get(i); // 第四步，创建单元格，并设置值 cell = row.createCell((short) 0); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getNewsId()); cell.setCellStyle(style); cell = row.createCell((short) 1); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getTypeId()); cell.setCellStyle(style); cell = row.createCell((short) 2); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getTitle()); cell.setCellStyle(style); cell = row.createCell((short) 3); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getPublishTime()); cell.setCellStyle(style); cell = row.createCell((short) 4); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getBody()); cell.setCellStyle(style); cell = row.createCell((short) 5); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getTag()); cell.setCellStyle(style); cell = row.createCell((short) 6); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getAuthor()); cell.setCellStyle(style); cell = row.createCell((short) 7); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getClicks()); cell.setCellStyle(style); cell = row.createCell((short) 8); // 设置编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(news.getImgUrl()); cell.setCellStyle(style); /*row.createCell((short) 0).setCellValue( news.getNewsId()); row.createCell((short) 1).setCellValue(news.getTypeId()); row.createCell((short) 2).setCellValue(news.getTitle()); // cell = row.createCell((short) 3); // cell.setCellValue(new SimpleDateFormat("yyyy-mm-dd").format(news.getPublishTime())); row.createCell((short) 3).setCellValue(news.getPublishTime()); row.createCell((short) 4).setCellValue(news.getBody()); row.createCell((short) 5).setCellValue(news.getTag()); row.createCell((short) 6).setCellValue(news.getAuthor()); row.createCell((short) 7).setCellValue(news.getClicks()); row.createCell((short) 8).setCellValue(news.getImgUrl());*/ } // 第六步，将文件存到指定位置 try { // String outputFile = "E:/news.xls"; // FileOutputStream fout = new FileOutputStream(outputFile);//"E:/news.xls" System.out.println("list="+list); wb.write(out); out.close(); } catch (Exception e) { e.printStackTrace(); } } }用servlet实现下载：此代码可以套用public class ExpExcelServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String fileName = "news.et"; response.setContentType("octets/stream"); response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "utf-8")); try { NewsDao dao = new NewsDao(); ArrayList<News> list = dao.queryAll(); CreateSimpleExcelToDisk ce=new CreateSimpleExcelToDisk(); OutputStream out = response.getOutputStream(); ce.ExpExcel(out); out.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("et导出成功！"); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request,response); } }网上的资料
可以采用： 1、RequestDispatcher的方式进行； 2、采用文件流输出的方式下载。 1、采用RequestDispatcher的方式进行 jsp页面中添加如下代码： <% response.setContentType("application/x-download");//设置为下载application/x-download String filedownload = "/要下载的文件名";//即将下载的文件的相对路径 String filedisplay = "最终要显示给用户的保存文件名";//下载文件时显示的文件保存名称 filenamedisplay = URLEncoder.encode(filedisplay,"UTF-8"); response.addHeader("Content-Disposition","attachment;filename=" + filedisplay); try { RequestDispatcher dis = application.getRequestDispatcher(filedownload); if(dis!= null) { dis.forward(request,response); } response.flushBuffer(); } catch(Exception e) { e.printStackTrace(); } finally { } %> 2、采用文件流输出的方式下载 <%@page language="java" contentType="application/x-msdownload" pageEncoding="gb2312"%><% //关于文件下载时采用文件流输出的方式处理： //加上response.reset()，并且所有的％>后面不要换行，包括最后一个； response.reset();//可以加也可以不加 response.setContentType("application/x-download"); String filedownload = "想办法找到要提供下载的文件的物理路径＋文件名"; String filedisplay = "给用户提供的下载文件名"; filedisplay = URLEncoder.encode(filedisplay,"UTF-8"); response.addHeader("Content-Disposition","attachment;filename=" + filedisplay); OutputStream outp = null; FileInputStream in = null; try { outp = response.getOutputStream(); in = new FileInputStream(filenamedownload); byte[] b = new byte[1024]; int i = 0; while((i = in.read(b)) > 0) { outp.write(b, 0, i); } outp.flush(); } catch(Exception e) { System.out.println("Error!"); e.printStackTrace(); } finally { if(in != null) { in.close(); in = null; } if(outp != null) { outp.close(); outp = null; } } %> 在wsad里面写JSP文件下载,总是出现这个异常,getOutputStream() has already been called for this response,输出流已经被调用了. 上网查半天终于明白一点,JSP早下载文件的时候用到了OutputStream,而在Application Server在处理编译jsp时对于％>和<％之间的内容一般是原样输出，而且默认是PrintWriter.
java生成excel表格和pdf并实现下载弹出框
时间： 2024-10-16 18:06:36