plupload批量上传分片(后台代码)

plupload批量上传分片功能，

对于文件比较大的情况下，plupload支持分片上传，后台代码如下：

    /**
     *
      * 方法：upLoadSpecialProgramPictrue
      * 方法说明：本地节目导入
      * @return
      * @author     wangHao
     * @throws Exception
      * @date       2015年6月9日
     */
    @RequestMapping("/localUpLoadProgram")
    @ResponseBody
    public void localUpLoadProgram(
            @RequestParam("file") CommonsMultipartFile[] file,
            HttpServletResponse response,HttpServletRequest request) throws Exception {

        boolean isMultipart = ServletFileUpload.isMultipartContent(request);
        if(isMultipart){
            String fileName = "";
            Integer chunk = 0, chunks = 0;

            //检查文件目录，不存在则创建
            String relativePath = "/plupload/files/";
            String realPath = ConfigUtil.class.getResource("/").getPath();
            File folder = new File(realPath + relativePath);
            if (!folder.exists()) {
                folder.mkdirs();
            }

            DiskFileItemFactory diskFactory = new DiskFileItemFactory();
            // threshold 极限、临界值，即硬盘缓存 1M
            diskFactory.setSizeThreshold(4 * 1024);

            ServletFileUpload upload = new ServletFileUpload(diskFactory);
            // 设置允许上传的最大文件大小（单位MB）
            upload.setSizeMax(1024 * 1048576);
            upload.setHeaderEncoding("UTF-8");
            List<FileItem> fileList = new ArrayList<FileItem>();
            fileList.add(file[0].getFileItem());
            Iterator<FileItem> it = fileList.iterator();
            FileItem item = it.next();
            String name = item.getFieldName();
            InputStream input = item.getInputStream();
            fileName = item.getName();
            chunk =  Integer.parseInt(request.getParameter("chunk"));
            chunks =  Integer.parseInt(request.getParameter("chunks"));
            // 处理上传文件内容
            if (!item.isFormField()) {
                //目标文件
                File destFile = new File(folder, fileName);
                //文件已存在删除旧文件（上传了同名的文件）
                if (chunk == 0 && destFile.exists()) {
                    destFile.delete();
                    destFile = new File(folder, fileName);
                }
                //合成文件
                appendFile(input, destFile);
                if (chunk == chunks - 1) {
                    System.out.println("上传完成");
                }else {
                    System.out.println("还剩["+(chunks-1-chunk)+"]个块文件");
                }
            }
        }
}
private void appendFile(InputStream in, File destFile) {
        OutputStream out = null;
        try {
            // plupload 配置了chunk的时候新上传的文件append到文件末尾
            if (destFile.exists()) {
                out = new BufferedOutputStream(new FileOutputStream(destFile, true), BUFFER_SIZE);
            } else {
                out = new BufferedOutputStream(new FileOutputStream(destFile),BUFFER_SIZE);
            }
            in = new BufferedInputStream(in, BUFFER_SIZE);

            int len = 0;
            byte[] buffer = new byte[BUFFER_SIZE];
            while ((len = in.read(buffer)) > 0) {
                out.write(buffer, 0, len);
            }
        } catch (Exception e) {
        } finally {
            try {
                if (null != in) {
                    in.close();
                }
                if(null != out){
                    out.close();
                }
            } catch (IOException e) {
            }
        }
    }