刚刚发表了一篇Java发送电子邮件,以前真是没注意,commons里这么多常用项目,惭愧呀,直到现在回顾;要学习的真是太多了,还是缺少真正的学习能力...
这里用到的是commons-fileupload.jar与commons-io.jar;下载地址http://commons.apache.org/
这是一个web工程,所以先在webroot下新建一个jsp,其实直接用index.jsp就行了;下面是前端代码:
View Code <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>文件上传</title></head><body><c:if test="${param.code=='001' }">操作成功</c:if><form action="file.jspx" method="post" enctype="multipart/form-data"> 文件描述:<input type="text" name="describe"/><br/> 文件位置<input type="file" name="file"/><br/><input type="submit" value="上传"/></form></body></html>这里表单请求到的是一个servlet,在src中创建一个Servlet,此处取名FileUpLoadServlet.java
代码实现如下:
View Code package com.wf.web;import java.io.File;import java.io.IOException;import java.text.SimpleDateFormat;import java.util.Date;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;public class FileUpLoadServlet extends HttpServlet {private static final long serialVersionUID = 1L; @Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { File file=new File("D:/upload");//上传文件保存位置 File tempfile=new File("D:/tempload");//上传缓存临时文件夹 if(!file.exists()){ file.mkdir(); }if(!tempfile.exists()){ tempfile.mkdir(); }//判断是否上传文件表单,也就是form中是否有enctype="multipart/form-data"项;必须post提交,get提交对内容长度有限制 if(ServletFileUpload.isMultipartContent(request)){ DiskFileItemFactory factory=new DiskFileItemFactory(); factory.setSizeThreshold(1024*512);//设置缓冲区大小 factory.setRepository(tempfile);//设置临时文件夹 ServletFileUpload fileUpload=new ServletFileUpload(factory); fileUpload.setFileSizeMax(10*1024*1024);//设置最大文件大小 try { @SuppressWarnings("unchecked") List<FileItem> items=fileUpload.parseRequest(request);//获取所有表单 for(FileItem item:items){//判断当前的表单控件是否是一个普通控件 if(!item.isFormField()){//是一个文件控件时 String name=item.getName(); System.out.println("上传文件名:"+name); System.out.println("文件大小:"+item.getSize()); String extName=name.substring(name.lastIndexOf(".")); String newName=new SimpleDateFormat("yyyyMMDDHHmmssms").format(new Date()); System.out.println("扩展名"+extName); item.write(new File("d:/upload/"+newName+extName)); }else{//是普通控件时 String desc=item.getString("UTF-8"); System.out.println("文件描述"+desc); } } } catch (Exception e) { e.printStackTrace(); } }else{throw new RuntimeException("请设置form表单的enctype属性"); } response.sendRedirect("index.jsp?code=001"); } @Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException { doGet(req, resp); }}这里对上传文件的名字做了改变,防止上传同名文件(若同名,后覆盖前);
还有一点要注意,要是把这些上传文件放到WebRoot跟目录下,file的路径就不能为"D:/upload"了
通过
String webRootPath = getServletContext().getRealPath("/"); System.out.println("webRootPath:" + webRootPath); File file = new File(webRootPath+"upload");获取webroot,最后将item.write(*****)更改为
item.write(new File(webRootPath+"upload/"+newName+extName));这样上传文件就保存到webroot下的upload文件夹中了
转载于:https://www.cnblogs.com/wufengxyz/archive/2011/11/27/2264746.html
相关资源：Java实现文件的上传下载