url传参为空怎么解决？

url=append+'/report/download2.do?name='+name传到后台name为空。

js

$("#btn_his_download").on("click", function () {
    var name = $("#lines").find("option:selected").text();
    var $form = $('<form method="GET"></form>');
    $form.attr('action', appName + '/report/download2.do?name='+name);
    $form.appendTo($('body'));
    $form.submit();
});

controller

@RequestMapping("/download2.do")
public void download2(HttpServletRequest request, HttpServletResponse response) throws IOException {
    String name = request.getParameter("name");
    System.out.println(name);
    String fileName = request.getSession().getServletContext().getRealPath("tcc/reports/upload/")+name;
    InputStream bis = new BufferedInputStream(new FileInputStream(new File(fileName)));
    name = URLEncoder.encode(name,"UTF-8");
    response.addHeader("Content-Disposition", "attachment;filename=" + name);
    response.setContentType("multipart/form-data");
    BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
    int len = 0;
    while((len = bis.read()) != -1){
        out.write(len);
        out.flush();
    }
    out.close();
}