jsp+servlet实现文件上传与下载功能

Java  /  管理员 发布于 7年前   173

本文实例为大家分享了jsp servlet实现文件上传与下载的具体代码，供大家参考，具体内容如下

上传：

需要导入两个包：commons-fileupload-1.2.1.jar,commons-io-1.4.jar

import java.io.File;import java.io.IOException;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.commons.fileupload.FileItem;import org.apache.commons.fileupload.disk.DiskFileItemFactory;import org.apache.commons.fileupload.servlet.ServletFileUpload;/** * 上传附件 * @author new * */public class UploadAnnexServlet extends HttpServlet { private static String path = ""; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } /* * post处理 * (non-Javadoc) * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { path = this.getServletContext().getRealPath("/upload"); try { DiskFileItemFactory factory = new DiskFileItemFactory(); ServletFileUpload up = new ServletFileUpload(factory); List<FileItem> ls = up.parseRequest(request); for (FileItem fileItem : ls) { if (fileItem.isFormField()) {  String FieldName = fileItem.getFieldName();  //getName()返回的是文件名字 普通域没有文件 返回NULL  //     String Name = fileItem.getName();  String Content = fileItem.getString("gbk");  request.setAttribute(FieldName, Content); } else {   String nm = fileItem.getName().substring(  fileItem.getName().lastIndexOf("\\") + 1);  File mkr = new File(path, nm);  if (mkr.createNewFile()) {  fileItem.write(mkr);//非常方便的方法  }  request.setAttribute("result", "上传文件成功！"); } } } catch (Exception e) { e.printStackTrace(); request.setAttribute("result", "上传失败，请查找原因，重新再试！"); } request.getRequestDispatcher("/pages/admin/annex-manager.jsp").forward( request, response); }}

下载（i/o流）无需导包：

import java.io.IOException;import java.net.URLEncoder;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * 下载文件 * @author * */public class DownloadFilesServlet extends HttpServlet { /** *  */ private static final long serialVersionUID = 8594448765428224944L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } /* * 处理请求 * (non-Javadoc) * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String name = request.getParameter("fileName"); System.out.print("dddddddddd:" + name); // web绝对路径 String path = request.getSession().getServletContext().getRealPath("/"); String savePath = path + "upload"; // 设置为下载application/x-download response.setContentType("application/x-download"); // 即将下载的文件在服务器上的绝对路径 String filenamedownload = savePath + "/" + name; // 下载文件时显示的文件保存名称 String filenamedisplay = name; // 中文编码转换 filenamedisplay = URLEncoder.encode(filenamedisplay, "UTF-8"); response.addHeader("Content-Disposition", "attachment;filename=" + filenamedisplay); try { java.io.OutputStream os = response.getOutputStream(); java.io.FileInputStream fis = new java.io.FileInputStream(  filenamedownload); byte[] b = new byte[1024]; int i = 0; while ((i = fis.read(b)) > 0) { os.write(b, 0, i); } fis.close(); os.flush(); os.close(); } catch (Exception e) { } }}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。