Javaweb 文件下载 通过绝对路径下载

 throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String filename = request.getParameter("filename");
//String folder = "/jier/";

    response.addHeader("Content-Type", "application/octet-stream");
    response.addHeader("Content-Disposition", "attachment;filename="+filename);
    //
    InputStream in = getServletContext().getResourceAsStream(folder+filename);
    //
    OutputStream out = response.getOutputStream();
    
    byte[] buffer = new byte[1024];
    int len;
     while((len = in.read(buffer))!= -1) {
         out.write(buffer,0,len);
     }
}https://img-mid.csdnimg.cn/release/static/image/mid/ask/401008025626115.png)

filename 是绝对路径 代码怎么写才能运行

是不能运行吗 什么问题 直接使用FileInputStream 把路径放进入得到InputStream 继续你现在的操作就好了 最后把流关闭