The Java web project implementation file downloads the instance code

File file = new File(path);//Path is spliced by log path and file name
    String filename = file.getName();//Gets the log file name
    InputStream fis = new BufferedInputStream(new FileInputStream(path));
    byte[] buffer = new byte[fis.available()];
    fis.read(buffer);
    fis.close();
    response.reset();
    //Remove the Spaces in the file name, and then convert the file name to utf-8, which is used to automatically display the file name in the browser's download box
    response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.replaceAll(" ", "").getBytes("utf-8"),"iso8859-1"));
    response.addHeader("Content-Length", "" + file.length());
    OutputStream os = new BufferedOutputStream(response.getOutputStream());
    response.setContentType("application/octet-stream");
    os.write(buffer);//The output file
    os.flush();
    os.close();

In struts2.0, you can use the method public void downloadFile(){}, return the value type void, and when called, directly write downloadfile.do to appear the download prompt