java實現檔案打包下載
阿新 • • 發佈：2018-12-05
業務場景：
從A伺服器通過SFTP將檔案下載到應用伺服器B，需要將檔案從應用伺服器B下載到使用者本地（檔案和應用都在B伺服器）
想法：
1. 想要通過FTP連線B伺服器下載，但是FTP只能下載到應用所在的本地，也就是隻能下載到下載到B伺服器，無法下載到使用者本地。
2. 通過普通的下載方式，用檔案流通過response下載，但是資料夾內有多個檔案，無法同時下載
實現：
採用將多個檔案打包下載
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //通過工號和日期去獲取相應的資料夾路徑 String usercode = request.getParameter("usercode"); String date = request.getParameter("date"); String formPath = "/tmp/ENongXian/"+usercode+"/"+date; //遍歷這個路徑下的所有檔名 List fileNames = this.getFileName(formPath); //如果找不到檔案 返回not found file if(fileNames == null||fileNames.size()==0){ PrintWriter out = response.getWriter(); response.setContentType("text/html; charset=GBK");//注意text/html，和application/html out.print("<html><body><script type='text/javascript'>alert('not found file');</script></body></html>"); out.flush(); out.close(); }else{ //開始批量壓縮下載 ZipOutputStream zos = new ZipOutputStream(response.getOutputStream()); response.setContentType("APPLICATION/OCTET-STREAM"); response.setHeader("Content-Disposition","attachment; filename="+this.getZipFilename()); System.out.println("in BatchDownload................"); File[] files = new File[fileNames.size()]; for(int i=0;i<files.length;i++){ String filename = fileNames.get(i).toString(); files[i] = new File(formPath+"/"+filename); } 將檔案進行壓縮 zipFile(files, "", zos); zos.flush(); zos.close(); } } private void zipFile(File[] subs, String baseName, ZipOutputStream zos) throws IOException { for (int i=0;i<subs.length;i++) { File f=subs[i]; zos.putNextEntry(new ZipEntry(baseName + f.getName())); FileInputStream fis = new FileInputStream(f); byte[] buffer = new byte[1024]; int r = 0; while ((r = fis.read(buffer)) != -1) { zos.write(buffer, 0, r); } fis.close(); } } private String getZipFilename(){ Date date=new Date(); String s=date.getTime()+".zip"; return s; } public List getFileName(String filePath){ File file = new File(filePath); List fileNameList = new ArrayList(); File[] fileList = file.listFiles(); if(fileList == null || fileList.length ==0){ return null; } for(int i=0;i<fileList.length;i++){ if("txt".equals(fileList[i].getName().substring(fileList[i].getName().lastIndexOf(".") + 1))){ continue; } if(fileList[i].isFile()){ String fileName = fileList[i].getName(); fileNameList.add(fileName); } } return fileNameList; }