文件上传

qsrock

使用apache的一个开源项目之一：commons-fileupload
很简单的一个使用，其实就是他里面文档中的例子。
本人只是写了个Servlet更具体化它而已。

Servlet:
import java.io.File;import java.io.IOException;import java.io.InputStream;import java.util.Iterator;import java.util.List;import javax.servlet.RequestDispatcher;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;/** *  * @author huanglq *  */public class Upload extends HttpServlet {private static final long serialVersionUID = 1L;//private String uploadPath = "/usr/upload/"; // 上传文件的目录private String tempPath = "/usr/upload/tmp/"; // 临时文件目录(上传文件的目的地)public static final long MAX_SIZE = 1024*100;public Upload() {super();}public void destroy() {}public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doPost(request, response);}@SuppressWarnings(value={"unchecked"})public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {try {/*//这是以前的方法，现在已经过时了DiskFileUpload fu = new DiskFileUpload();// 设置最大文件尺寸，这里是4MBfu.setSizeMax(4194304);// 设置缓冲区大小，这里是4kbfu.setSizeThreshold(4096);// 设置临时目录：fu.setRepositoryPath(tempPath);// 得到所有的文件：List fileItems = fu.parseRequest(request);Iterator i = fileItems.iterator();// 依次处理每一个文件：while (i.hasNext()) {FileItem fi = (FileItem) i.next();// 获得文件名，这个文件名包括路径：String fileName = fi.getName();// 在这里可以记录用户和文件信息// ...// 写入文件，暂定文件名为a.txt，可以从fileName中提取文件名：fi.write(new File(uploadPath + "a.txt"));}*//* * 方法1： * 可以上传多个文件不能指定文件大小 */// Check that we have a file upload requestboolean isMultipart = ServletFileUpload.isMultipartContent(request);System.out.println("isMultipart :"+isMultipart);/*// Create a factory for disk-based file itemsFileItemFactory factory = new DiskFileItemFactory();// Create a new file upload handlerServletFileUpload upload = new ServletFileUpload(factory);// Parse the requestList  FileItem  items = upload.parseRequest(request);*//* * 方法2:能指定文件大小,超过文件的大小则抛异常 */// Create a factory for disk-based file itemsDiskFileItemFactory factory = new DiskFileItemFactory();// Set factory constraintsfactory.setSizeThreshold(4096);// 设置缓冲区大小，这里是4kbfactory.setRepository(new File(tempPath));//设置// Create a new file upload handlerServletFileUpload upload = new ServletFileUpload(factory);// Set overall request size constraint//upload.setSizeMax(1024*1024*4);// 设置最大文件尺寸，这里是4MBupload.setSizeMax(MAX_SIZE);// 设置最大文件尺寸，这里是100K,如果上传的文件大于100K程序就出异常// Parse the requestList<FileItem> /* FileItem */ items = upload.parseRequest(request);// Process the uploaded itemsIterator<FileItem> iter = items.iterator();while (iter.hasNext()) {    FileItem item = (FileItem) iter.next(); // Process a regular form field    if (item.isFormField()) {        String name = item.getFieldName();        String value = item.getString();        System.out.println("----------------------");        System.out.println("name : "+name);//name : Submit 提交        System.out.println("value : "+value);//value : upload 提交的action        System.out.println("----------------------");    } // Process a file upload    boolean flag=!item.isFormField();    if (flag) {        String fieldName = item.getFieldName();        String fileName = item.getName();        String contentType = item.getContentType();        boolean isInMemory = item.isInMemory();        long sizeInBytes = item.getSize();        //取文件名        fileName=fileName.substring(fileName.lastIndexOf("\\")+1,fileName.length());        System.out.println("fieldName : "+fieldName);        System.out.println("fileName :"+fileName);        System.out.println("contentType : "+contentType);        System.out.println("isInMemory : "+isInMemory);        System.out.println("sizeInBytes : "+sizeInBytes);        System.out.println("***********");             // Process a file upload        if (flag) {        if(!fileName.equals("")&&!(fileName==null)){//如果fileName为null，即没有上传文件        File uploadedFile = new File("/usr/upload/tmp/"+fileName);            item.write(uploadedFile);        }        } else {            InputStream uploadedStream = item.getInputStream();            //File uploadedFile = new File("/usr/upload/test.txt");            //uploadedStream            uploadedStream.close();        }    }    /*if (item.isFormField()) {        processFormField(item);    } else {        processUploadedFile(item);    }*/}System.out.println("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX");request.setAttribute("uploadSuccess", items);RequestDispatcher rd=request.getRequestDispatcher("index.jsp");rd.forward(request, response);} catch (Exception e) {// 可以跳转出错页面System.out.println("ERROR");e.printStackTrace();request.setAttribute("uploadFail", "你上传的文件大于100k!");RequestDispatcher rd=request.getRequestDispatcher("index.jsp");rd.forward(request, response);}}public void init() throws ServletException {// Put your code here}}
Jsp页面：
<%@ page language="java" pageEncoding="gbk"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>        <title>fileUpload</title><%if(!((request.getAttribute("uploadSuccess"))==null) && !request.getAttribute("uploadSuccess").equals("")){%><script type="text/javascript">alert("文件上传成功！");</script><% } %> <%if(!((request.getAttribute("uploadFail"))==null) && !request.getAttribute("uploadFail").equals("")){%><script type="text/javascript">alert("你上传的文件大于100k!");</script><% } %>  </head>  <body><form action="fileupload" method="post" enctype="multipart/form-data" name="form1"><input type="file" name="file"><input type="file" name="file"><input type="submit" name="Submit" value="upload"></form>  </body></html>
web.xml:<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.4" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee   http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">  <servlet>    <servlet-name>Upload</servlet-name>    <servlet-class>com.huanglq.util.Upload</servlet-class>  </servlet><servlet>    <servlet-name>Download</servlet-name>    <servlet-class>com.huanglq.util.Download</servlet-class>  </servlet>  <servlet-mapping>    <servlet-name>Upload</servlet-name>    <url-pattern>/fileupload</url-pattern>  </servlet-mapping>  <servlet-mapping>  <servlet-mapping>    <servlet-name>Download</servlet-name>    <url-pattern>/download</url-pattern>  </servlet-mapping>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list></web-app>