java/servlet 断点下载

  //被下载文件路径名称
        String path = "D:\\TDDownload\\system\\",fileName="cn_windows_8_1_pro_vl_x86_dvd_2972620.iso";
        File file = new File(path+fileName);
        InputStream in = new FileInputStream(file);
        OutputStream os=  resp.getOutputStream();
        //清空response 缓存中数据，仅保留状态码及Header
        resp.reset();

        byte [] buffer  =   new  byte [128];
        long downloaded=0;
        String range =  req.getHeader("range");
        if(range != null){
            downloaded = Long.parseLong(range.split("-")[0].split("=")[1]);
            //设置 206状态表示可以断点下载
            resp.setStatus(206);
            //设置下载的范围
            resp.setHeader("Content-Range","bytes "+downloaded+"-"+file.length()+"/"+file.length());
        }
        resp.setContentType("application/octet-stream");
        //文件名
        resp.addHeader("Content-Disposition", "attachment; filename="+new String(fileName.getBytes()));
        //文件大小
        resp.addHeader("Content-Length", file.length() + "");
        //接受范围 bytes
        resp.setHeader("Accept-Ranges", "bytes");
        int len = 0;
        while ((len=in.read(buffer))!=-1){
            os.write(buffer,0,len);
        }
        in.close();
        os.flush();
        os.close();

java/servlet 断点下载

原文：http://blog.csdn.net/sc_jelly/article/details/19151287