commons-fileupload文件上传、下载

今天复习了下commons-fileupload文件上传，写了个demo。需要的jar包为：commons-fileupload-1.2.1.jar、commons-io-1.4.jar。都可去apache下的commons下下载。

一、上传

1、index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%String path = request.getContextPath();String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><base href="<%=basePath%>"><title>My JSP 'index.jsp' starting page</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"></head><body><form action="/commons-fileupload/UploadServlet" method="post" enctype="multipart/form-data">username:<input type="text" name="username"><br>password:<input type="password" name="password"><br>file1:<input type="file" name="file1"><br>file2:<input type="file" name="file2"><br><input type="submit" value="submit"></form></body></html>

2、UploadServlet.java

package com.fileupload.servlet;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;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;@SuppressWarnings("serial")public class UploadServlet extends HttpServlet {@SuppressWarnings({ "unchecked", "deprecation" })public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("UTF-8");//设置文件存储路径String path = request.getRealPath("/upload");//实例化工厂DiskFileItemFactory factory = new DiskFileItemFactory();//设置在内存中存储文件的的大小为1M，如果超出1M，将写入磁盘factory.setSizeThreshold(1024*1024); //如果文件超出1M，将写入磁盘factory.setRepository(new File(path));ServletFileUpload servletFileUpload = new ServletFileUpload(factory);try { //将request解析成FileItem,每个FileItem对应页面的一个输入对象。List<FileItem> list = servletFileUpload.parseRequest(request);for(FileItem item :list){if(item.isFormField()){//如果输入域是普通类型type=text（非file类型）String name = item.getFieldName();String value = item.getString("UTF-8");request.setAttribute(name, value);}else{//如果输入域是type=file类型String name = item.getFieldName();String value = item.getName();//将取到如下内容：eg：C:/Documents and Settings/liu/桌面/test.docint start = value.lastIndexOf("//");String fileName = value.substring(start+1);//解析成test.docrequest.setAttribute(name, fileName);////使用普通流写入文件//OutputStream out = new FileOutputStream(new File(path+"/"+fileName));//InputStream in = item.getInputStream();//byte buffer[]= new byte[1024];//int length = 0;//while((length=in.read(buffer))>0){//out.write(buffer,0,length);//}//out.flush();//out.close();//in.close();//使用FileItem提供的方法，方便的输出item.write(new File(path+"/"+fileName));}}} catch (Exception e) {e.printStackTrace();}request.getRequestDispatcher("success.jsp").forward(request, response);}}

3、success.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP 'success.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"> </head> <body> username:${username }<br> password:${password }<br> file1:${file1 }<br> file2:${file2 }<br> </body></html>

4、web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" 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_2_5.xsd"> <servlet> <servlet-name>UploadServlet</servlet-name> <servlet-class>com.fileupload.servlet.UploadServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>UploadServlet</servlet-name> <url-pattern>/UploadServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list></web-app>

二：下载：

下载文件用一个Servlet完成:

response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("UTF-8"); PrintWriter out = response.getWriter(); Long id=Long.valueOf(request.getParameter("id")); FileInfo fileInfo=fileDAO.find(id);response.setContentType("application/x-msdownload;");//此行代码是防止中文乱码的关键！！ response.setHeader("Content-disposition","attachment; filename="+new String(fileInfo.getName().getBytes("gb2312"),"iso8859-1")); BufferedInputStream bis=new BufferedInputStream(new FileInputStream(fileInfo.getPath())); BufferedOutputStream bos=new BufferedOutputStream(response.getOutputStream()); //新建一个2048字节的缓冲区 byte[] buff=new byte[2048]; int bytesRead; while((bytesRead=bis.read(buff, 0, buff.length))!=-1) { bos.write(buff); } if (bis != null) bis.close(); if (bos != null) bos.close(); }

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commons-fileupload文件上传、下载

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