2011级-csdn-java-张侃— JDBC开发—文件的上传和下载（一）

private String id;

private String savename; //上传文件的名称，文件的uuid名

private String realName; //上传文件的真实名称

private String savepath; //记住文件的位置

private Date uptime; //文件的上传时间

private String description; //文件的描述

private String username; //上传人

Tip：课程总结

通过本课程你应该熟练掌握了在web应用中集成apache commons fileupload组件上传多个文件。

在实际项目应用中，上传文件所引发的存储问题、安全性问题。

实现上传文件的下载

UploadServlet.java代码

package com.csdn.web.servlet;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.csdn.domain.Upfile;import com.csdn.service.FileDaoService;import com.csdn.utils.WebUtil;public class UploadServlet extends HttpServlet {/*** */private static final long serialVersionUID = 1L;public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {Upfile upfile = null;try {upfile = WebUtil.doFile(request, this.getServletContext().getRealPath("/WEB-INF/upload"), Upfile.class);} catch (Exception e) {request.setAttribute("message", "上传失败");request.getRequestDispatcher("/message.jsp").forward(request,response);return;}try{FileDaoService service = new FileDaoService();service.add(upfile);request.setAttribute("message", "上传成功");}catch(Exception e){request.setAttribute("message", "上传成功，保存数据失败");}request.getRequestDispatcher("/message.jsp").forward(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

ListFileServlet.java代码

package com.csdn.web.servlet;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 com.csdn.domain.Upfile;import com.csdn.service.FileDaoService;public class ListFileServlet extends HttpServlet {/*** */private static final long serialVersionUID = 1L;public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {FileDaoService service = new FileDaoService();List<Upfile> list = service.getAllFile();request.setAttribute("list", list);request.getRequestDispatcher("/listfile.jsp").forward(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

DownFileServlet.java代码

package com.csdn.web.servlet;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.OutputStream;import java.net.URLEncoder;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.csdn.domain.Upfile;import com.csdn.service.FileDaoService;public class DownFileServlet extends HttpServlet {/*** */private static final long serialVersionUID = 1L;public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {String id = request.getParameter("id");FileDaoService service = new FileDaoService();Upfile upfile = service.findFile(id);if(upfile==null){request.setAttribute("message", "该资源已被删除了");request.getRequestDispatcher("/message.jsp").forward(request, response);return;}String savepath = upfile.getSavepath();String uuidname = upfile.getUuidname();String realname = upfile.getRealname();File f = new File(savepath+"\\"+uuidname);response.setHeader("content-disposition", "attachment;filename="+URLEncoder.encode(realname,"UTF-8"));FileInputStream in = new FileInputStream(f);OutputStream out = response.getOutputStream();byte[] buf = new byte[1024];int len = 0;while((len=in.read(buf))>0){out.write(buf, 0, len);}in.close();}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

WebUtil.java代码

package com.csdn.utils;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.util.Date;import java.util.List;import java.util.UUID;import javax.servlet.http.HttpServletRequest;import org.apache.commons.beanutils.BeanUtils;import org.apache.commons.fileupload.FileItem;import org.apache.commons.fileupload.disk.DiskFileItemFactory;import org.apache.commons.fileupload.servlet.ServletFileUpload;import com.csdn.domain.Upfile;public class WebUtil {@SuppressWarnings("unchecked")public static <T> Upfile doFile(HttpServletRequest request,String realPath, Class<T> clazz) {try {DiskFileItemFactory factory = new DiskFileItemFactory();factory.setRepository(new File(request.getSession().getServletContext().getRealPath("/temp")));ServletFileUpload upload = new ServletFileUpload(factory);upload.setHeaderEncoding("UTF-8");List<FileItem> list = upload.parseRequest(request);Upfile upfile = (Upfile) clazz.newInstance();for (FileItem item : list) {if (item.isFormField()) {String inputname = item.getFieldName();String inputvalue = item.getString("UTF-8");// System.out.println(inputname+"..."+inputvalue);BeanUtils.setProperty(upfile, inputname, inputvalue);} else {String filename = item.getName();String realname = filename.substring(filename.lastIndexOf("\\") + 1);upfile.setRealname(realname);String uuidname = generateuuidName(realname);upfile.setUuidname(uuidname);String savepath = generateSavepath(realname, realPath);upfile.setSavepath(savepath);InputStream in = item.getInputStream();FileOutputStream out = new FileOutputStream(savepath + "\\"+ uuidname);byte[] buf = new byte[1024];int len = 0;while ((len = in.read(buf)) > 0) {out.write(buf, 0, len);}in.close();out.close();item.delete();}upfile.setId(UUID.randomUUID().toString());upfile.setUptime(new Date());}return upfile;} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e);}}private static String generateSavepath(String realname, String realPath) {int dir1 = realname.hashCode() & 0xf;int dir2 = (realname.hashCode() >> 4) & 0xf;String savepath = realPath + "\\" + dir1 + "\\" + dir2;File f = new File(savepath);if (!f.exists()) {f.mkdirs();}return savepath;}private static String generateuuidName(String realname) {String ext = realname.substring(realname.lastIndexOf("."));return UUID.randomUUID().toString() + ext;}}

upload.jsp代码

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>上传文件</title></head><body><form action="UploadServlet" method="post" enctype="multipart/form-data"><table align="center" border="1" width="80%"><tr><td>用户名:</td><td><input type="text" name="username" /></td></tr><tr><td>文件:</td><td><input type="file" name="file" /></td></tr><tr><td>文件描述:</td><td><textarea name="description"></textarea></td></tr><tr><td></td><td><input type="submit" value="上传"></td></tr></table></form></body></html>

listfile.jsp代码

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>下载的资源列表</title></head><body><table border="1px" width="80%"><tr><td>文件名</td><td>文件描述</td><td>上传时间</td><td>上传用户</td><td>操作</td></tr><c:forEach items="${list}" var="me"><tr><td>${me.realname }</td><td>${me.description }</td><td>${me.uptime }</td><td>${me.username }</td><td><a href="DownFileServlet?id=${me.id }">下载</a>|<a href="DeleteFileServlet?id=${me.id }">删除</a></td></tr></c:forEach></table></body></html>