commons-fileupload文件上传、下载

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commons-fileupload文件上传、下载

2013年10月03日 ⁄ 综合 ⁄ 共 5289字 ⁄ 字号小中大 ⁄ 评论关闭

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"> password: <input type="password" name="password"> file1: <input type="file" name="file1"> file2: <input type="file" name="file2"> <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.doc int start = value.lastIndexOf("//"); String fileName = value.substring(start+1);//解析成test.doc request.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:${username } password:${password } file1:${file1 } file2:${file2 } </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(); }

【上篇】2-d树头文件C语言
【下篇】中兴V880刷机后无法打开数据连接的解决

作者: gargoyle

该日志由 gargoyle 于11年前发表在综合分类下，最后更新于 2013年10月03日.
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commons-fileupload文件上传、下载

作者: gargoyle

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