java文件上传通用（分片）

/**
 * 
 * 上传通用
 * 
 * */
@RequestMapping(value = "/reportUploader", method = RequestMethod.POST)
public void uploadMajInnovation(HttpServletRequest request, HttpServletResponse response, @RequestParam("access_token") String access_token) {
    Teacher teacher = (Teacher) request.getServletContext().getAttribute(access_token);
    teacher.getSchoolNumber();
    try {
        boolean isMultipart = ServletFileUpload.isMultipartContent(request);
        if (isMultipart) {
            FileItemFactory factory = new DiskFileItemFactory();
            ServletFileUpload upload = new ServletFileUpload(factory);
            // 得到所有的表单域，它们目前都被当作FileItem
            List<FileItem> fileItems = upload.parseRequest(request);
            String id = "";
            String fileName = "";
            // 如果大于1说明是分片处理
            int chunks = 1;
            int chunk = 0;
            FileItem tempFileItem = null;
            for (FileItem fileItem : fileItems) {
                if (fileItem.getFieldName().equals("id")) {
                    id = fileItem.getString();
                } else if (fileItem.getFieldName().equals("name")) {
                    fileName = new String(fileItem.getString().getBytes("ISO-8859-1"), "UTF-8");
                } else if (fileItem.getFieldName().equals("chunks")) {
                    chunks = NumberUtils.toInt(fileItem.getString());
                } else if (fileItem.getFieldName().equals("chunk")) {
                    chunk = NumberUtils.toInt(fileItem.getString());
                } else if (fileItem.getFieldName().equals("multiFile")) {
                    tempFileItem = fileItem;
                }
            }
            String filePath = ConfigUtil.static_dir + teacher.getSchoolNumber() + "/development/";
            String realname = fileName.substring(0, fileName.lastIndexOf("."));
            // 临时目录用来存放所有分片文件
            String tempFileDir = filePath + File.separator + id;
            File parentFileDir = new File(tempFileDir);
            if (!parentFileDir.exists()) {
                parentFileDir.mkdirs();
            }
            // 分片处理时，前台会多次调用上传接口，每次都会上传文件的一部分到后台
            File tempPartFile = new File(parentFileDir, realname + ".part");
            FileUtils.copyInputStreamToFile(tempFileItem.getInputStream(), tempPartFile);
            // 是否全部上传完成
            // 所有分片都存在才说明整个文件上传完成
            boolean uploadDone = true;
            for (int i = 0; i < chunks; i++) {
                File partFile = new File(parentFileDir, realname+ ".part");
                if (!partFile.exists()) {
                    uploadDone = false;
                }
            }
            // 所有分片文件都上传完成
            // 将所有分片文件合并到一个文件中
            if (uploadDone) {
                File destfile = new File(filePath);
                if (!destfile.exists()) {
                    destfile.mkdirs();
                }
                
                // 得到 destTempFile 就是最终的文件
                File destTempFile = new File(filePath, realname + "."+ fileName.substring(fileName.lastIndexOf(".") + 1));
                File partFile = new File(parentFileDir, realname + ".part");
                
                if(!destTempFile.exists()){
                    for (int i = 0; i < chunks; i++) {
                        FileOutputStream destTempfos = new FileOutputStream(destTempFile, true);
                        // 遍历"所有分片文件"到"最终文件"中
                        FileUtils.copyFile(partFile, destTempfos);
                        destTempfos.close();
                    }
                }
                
                //文件重命名（时间戳）
                Long newname = new Date().getTime();
                destTempFile.renameTo(new File(filePath, newname + "."+ fileName.substring(fileName.lastIndexOf(".") + 1)));
                
                request.getSession().removeAttribute("EnterpriseFile");
                // 将文件信息存储在session中
                CareerPlanFile cpf = new CareerPlanFile();
                cpf.setFileName(fileName);
                cpf.setFilePath(destTempFile.getAbsolutePath());
                request.getSession().setAttribute("EnterpriseFile", cpf);
                // 删除临时目录中的分片文件
                FileUtils.deleteDirectory(parentFileDir);
                
                
            } else {
                // 临时文件创建失败
                if (chunk == chunks - 1) {
                    FileUtils.deleteDirectory(parentFileDir);
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}