发布于 2017-11-11 12:28:22 | 173 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的Java并发编程示例,程序狗速度看过来!

Java程序设计语言

java 是一种可以撰写跨平台应用软件的面向对象的程序设计语言,是由Sun Microsystems公司于1995年5月推出的Java程序设计语言和Java平台(即JavaEE(j2ee), JavaME(j2me), JavaSE(j2se))的总称。


这篇文章主要为大家详细介绍了javaweb文件打包批量下载代码,批量下载未批改作业,感兴趣的小伙伴们可以参考一下

本文实例为大家分享了javaweb文件打包批量下载,供大家参考,具体内容如下


// 批量下载未批改作业
 @RequestMapping(value = "/downloadAllHomework", method = RequestMethod.GET)
 public void downloadAllHomework(HttpSession httpSession, HttpServletRequest request, HttpServletResponse response, String assignmentid, int classCode) throws Exception {

  Site site = (Site) httpSession.getAttribute("site");
  String siteid = site.getId();

  // 根据作业ID获取作业详细信息
  AssignmentDetail assignmentDetail = assignmentServiceWS.getAssignmentDetail(assignmentid);
  generateParameters(assignmentDetail);

  // 信息不完整,后面需要填充。
  List<AssignmentSubmit> assignmentSubmitList = assignmentServiceWS.getSubmitedAssignmentStudent(assignmentid);

  // 获取所有的submitid
  List<String> submitids = new ArrayList<String>();
  for (int i = 0; i < assignmentSubmitList.size(); i++) {
   String submitid = assignmentSubmitList.get(i).getId();
   if (submitid == null || submitid == "")
    continue;
   submitids.add(submitid);
  }
  // 获取提交详情
  List<AssignmentSubmit> assignmentSubmits = new ArrayList<AssignmentSubmit>();
  for (String a : submitids) {
   AssignmentSubmit as = assignmentServiceWS.getSubmitAssignment(a);
   assignmentSubmits.add(as);
  }
  // 给每个已提交作业的学生配一个map,userName-->AssignmentSubmit
  Map<String, AssignmentSubmit> studentSubmitMap = new HashMap<String, AssignmentSubmit>();
  for (AssignmentSubmit assignmentSubmit : assignmentSubmits) {
   String studentID = assignmentSubmit.getUserName();
   studentSubmitMap.put(studentID, assignmentSubmit);
  }
  // 根据班级号获取该班所有学生的学号,再根据学号获取详情列表
  List<AssignmentSubmit> assignmentStudentList = new ArrayList<AssignmentSubmit>();

  List<MemberVO> studentList = memberServiceWS.getStudents(siteid, classCode);
  for (MemberVO student : studentList) {

   String userName = student.getId();
   String realName = student.getName();
   AssignmentSubmit assignmentSubmit = new AssignmentSubmit();
   if (studentSubmitMap.get(userName) != null) {
    assignmentSubmit = studentSubmitMap.get(userName);
   }
   assignmentSubmit.setRealName(realName);
   assignmentSubmit.setUserName(userName);
   generateA(assignmentSubmit);
   assignmentStudentList.add(assignmentSubmit);
  }

  List<AssignmentSubmit> submitedList = new ArrayList<AssignmentSubmit>();
  for (AssignmentSubmit as : assignmentStudentList) {
   if (as.getGradePoint() == null && as.getAssignmentID() != null)
    submitedList.add(as);
  }

  List<File> files = new ArrayList<File>();

  File file = new File("d:/css.rar");
  if (!file.exists()) {
   file.createNewFile();
  }
  response.reset();
  // response.getWriter()
  // 创建文件输出流
  FileOutputStream fous = new FileOutputStream(file);

  // 打包的方法我们会用到ZipOutputStream这样一个输出流, 所以这里我们把输出流转换一下

  ZipOutputStream zipOut = new ZipOutputStream(fous);
  for (AssignmentSubmit a : submitedList) {

   for (AttachIDs aa : a.getAttachIDs()) {
    try {
     String fileId = aa.getId();
     String cloudFileUrl = "http://xxx.xxx.xxx.xxx:8066/ImageService/DownloadFile/";
     String fileUrl = announceService.getAttachmentByFileid(fileId).getUrlUpload();
     fileUrl = fileUrl.substring(fileUrl.lastIndexOf("/") + 1);
     fileUrl = cloudFileUrl + fileUrl;
     String fileName = announceService.getAttachmentByFileid(fileId).getName(); // 获取远程文件的文件名。
     // response.addHeader("Content-Disposition", "attachment;filename=" +
     // new String(fileName.getBytes("gbk"), "iso-8859-1"));
     // iso-8859-1
     ZipEntry entry = new ZipEntry(new String(fileName.getBytes("gbk"), "iso-8859-1"));
     zipOut.putNextEntry(entry);
     URL urlfile = null;
     HttpURLConnection httpUrl = null;
     urlfile = new URL(fileUrl);
     httpUrl = (HttpURLConnection) urlfile.openConnection();
     httpUrl.connect();
     InputStream downloadFile = httpUrl.getInputStream();
     int len = 0;
     byte[] buf = new byte[1024];
     while ((len = downloadFile.read(buf, 0, 1024)) != -1) {
      zipOut.write(buf, 0, len);
     }
    } catch (JSONException e) {
     e.printStackTrace();
    } catch (UnsupportedEncodingException e) {
     e.printStackTrace();
    }
   }
  }
  zipOut.close();
  fous.close();
  downloadZip(file, response);
 }
 // 把接受的全部文件打成压缩包
 public static HttpServletResponse downloadZip(File file, HttpServletResponse response) {
  try {
   // 以流的形式下载文件。
   InputStream fis = new BufferedInputStream(new FileInputStream(file.getPath()));
   byte[] buffer = new byte[fis.available()];
   fis.read(buffer);
   fis.close();
   // 清空response
   response.reset();
   OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
   response.setContentType("application/octet-stream");

   // 如果输出的是中文名的文件,在此处就要用URLEncoder.encode方法进行处理
   response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(file.getName(), "UTF-8"));
   toClient.write(buffer);
   toClient.flush();
   toClient.close();
  } catch (IOException ex) {
   ex.printStackTrace();
  } finally {
   try {
    File f = new File(file.getPath());
    f.delete();
   } catch (Exception e) {
    e.printStackTrace();
   }
  }
  return response;

 }

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