<form action="FileServlet" method="post" enctype="multipart/form-data">        <input type="file" name="myfile">         <input type="text" name="cmt" value="example示例">         <input type="submit">    </form>

<a href="FileServlet?filename=1.xlsx">download</a>

import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.jspsmart.upload.File;import com.jspsmart.upload.Request;import com.jspsmart.upload.SmartUpload;import com.jspsmart.upload.SmartUploadException;public class FileServlet extends HttpServlet {    @Override    protected void doGet(HttpServletRequest request,            HttpServletResponse response) throws ServletException, IOException {        String strName = request.getParameter("filename");        if (strName == null) {            return;        }        // new一下        SmartUpload su = new SmartUpload();        // 初始化        su.initialize(getServletConfig(), request, response);        // 初始化        su.setContentDisposition(null);        try {            su.downloadFile("up/" + strName);        } catch (SmartUploadException e) {            e.printStackTrace();        }        // 下载就不用重定向了，响应已经提交过了，会出错：        // Cannot call sendRedirect() after the response has been committed        //response.sendRedirect("upload.jsp");    }    public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        // new一下        SmartUpload su = new SmartUpload();        // 初始化        su.initialize(getServletConfig(), request, response);        try {            su.upload();            File f = su.getFiles().getFile(0);            // SAVE_PHYSICAL 操作系统根目录            // SAVE_VIRTUAL Web应用根目录            // SAVE_AUTO 组件自己选择            f.saveAs("up/" + f.getFileName(), SmartUpload.SAVE_VIRTUAL);        } catch (SmartUploadException e) {            e.printStackTrace();        }        // ↓↓↓取参数        String sevletP = request.getParameter("cmt");        System.out.println("直接获取参数不可以:" + sevletP);        Request request2 = su.getRequest();        String suP = request2.getParameter("cmt");        System.out.println("通过SmartUpload对象间接获取参数:" + suP);        // ↑↑↑取参数        // 转去下载页面        response.sendRedirect("download.jsp");    }}

<?xml version="1.0" encoding="UTF-8"?><web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">    <servlet>        <servlet-name>FileServlet</servlet-name>        <servlet-class>FileServlet</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>FileServlet</servlet-name>        <url-pattern>/FileServlet</url-pattern>    </servlet-mapping>    <welcome-file-list>        <welcome-file>upload.jsp</welcome-file>    </welcome-file-list></web-app>