<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<servlet>
<servlet-name>UploadServlet</servlet-name>
<servlet-class>com.zr.uploaddownload.servlet.UploadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>UploadServlet</servlet-name>
<url-pattern>/UploadServlet</url-pattern>
</servlet-mapping>
</web-app>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>test upload</title> </head> <body> <form action="UploadServlet" method="post" enctype="multipart/form-data"> 上传文件：<input type="file" name="file"/><br><br> <span>文件介绍：</span><br> <textarea rows="5" cols="35" name="text"></textarea> <br><br> <input type="submit" value="提交"> </form> </body> </html>
package com.zr.uploaddownload.servlet; import java.io.File; import java.io.IOException; import java.util.Date; import java.util.Iterator; 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.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; /** * * @author lf * */ public class UploadServlet extends HttpServlet{ private static final long serialVersionUID = 1L; @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // System.out.println("UploadServlet...doPost..."); //设置编码（应该在filter进行设置编码） /*req.setCharacterEncoding("utf-8"); resp.setCharacterEncoding("utf-8");*/ // 创建DiskFileItem工厂 DiskFileItemFactory factory = new DiskFileItemFactory(); // 设置内存大小 factory.setSizeThreshold(1024*1024); //设置超出内存大小时，文件的临时存放路径 factory.setRepository(new File("D:\\tempFile")); // 创建上传的对象 ServletFileUpload upload = new ServletFileUpload(factory); // 设置单个文件上传的最大值（5M） upload.setSizeMax(1024*1024*5); List<FileItem> items = null; try { // 解析请求 items = upload.parseRequest(req); Iterator<FileItem> iter = items.iterator(); while (iter.hasNext()) { FileItem item = (FileItem) iter.next(); if (item.isFormField()) { //文本域处理 String name = item.getFieldName(); String value = item.getString(); System.out.println("name:"+name+"\nvalue:"+value); } else { //文件域处理 String fieldName = item.getFieldName(); //获取文件名 String fileName = item.getName(); String contentType = item.getContentType(); boolean isInMemory = item.isInMemory(); long sizeInBytes = item.getSize(); System.out.println("fieldName:"+fieldName +"\nfileName"+fileName+"\ncontentType" +contentType+"\nisInMemory"+isInMemory +"\nsizeInBytes"+sizeInBytes); //文件名 String name = fileName.substring(fileName.indexOf(".")); //通过随机数产生文件名 String str = new Date().getTime()+""+(int)Math.random()*10000; //上传文件保存的路径 String path = "D:\\"+str+name; File uploadedFile = new File(path); // 将路径写入数据库（在此不进行写入数据库的操作） try { item.write(uploadedFile); } catch (Exception e) { e.printStackTrace(); } } } } catch (FileUploadException e) { e.printStackTrace(); } } }
原文：http://www.cnblogs.com/lantu1989/p/6257633.html