标签: uploadfileimportexceptionstringmyeclipse
2012-09-06 19:55 1497人阅读 评论(0) 收藏 举报
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好东东(2) Java(2)
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Apache的commons-fileupload.jar可方便的实现文件的上传功能,本文通过实例来介绍如何使用commons-fileupload.jar。
@author:ZJ 07-2-22
Blog: [url]http://zhangjunhd.blog.51cto.com/[/url]
将Apache的commons-fileupload.jar放在应用程序的WEB-INF\lib下,即可使用。下面举例介绍如何使用它的文件上传功能。
所使用的fileUpload版本为1.2,环境为Eclipse3.3+MyEclipse6.0。FileUpload 是基于 Commons IO的,所以在进入项目前先确定Commons IO的jar包(本文使用commons-io-1.3.2.jar)在WEB-INF\lib下。
此文作示例工程可在文章最后的附件中下载。
示例1
最简单的例子,通过ServletFileUpload静态类来解析Request,工厂类FileItemFactory会对mulipart类的表单中的所有字段进行处理,不只是file字段。getName()得到文件名,getString()得到表单数据内容,isFormField()可判断是否为普通的表单项。
demo1.html
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB18030"> <title>File upload</title> </head> <body> //必须是multipart的表单数据。 <form name="myform" action="demo1.jsp" method="post" enctype="multipart/form-data"> Your name: <br> <input type="text" name="name" size="15"><br> File:<br> <input type="file" name="myfile"><br> <br> <input type="submit" name="submit" value="Commit"> </form> </body> </html> |
demo1.jsp
<%@ page language="java" contentType="text/html; charset=GB18030" pageEncoding="GB18030"%> <%@ page import="org.apache.commons.fileupload.*"%> <%@ page import="org.apache.commons.fileupload.servlet.*"%> <%@ page import="org.apache.commons.fileupload.disk.*"%> <%@ page import="java.util.*"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <% boolean isMultipart = ServletFileUpload.isMultipartContent(request);//检查输入请求是否为multipart表单数据。 if (isMultipart == true) { FileItemFactory factory = new DiskFileItemFactory();//为该请求创建一个DiskFileItemFactory对象,通过它来解析请求。执行解析后,所有的表单项目都保存在一个List中。 ServletFileUpload upload = new ServletFileUpload(factory); List<FileItem> items = upload.parseRequest(request); Iterator<FileItem> itr = items.iterator(); while (itr.hasNext()) { FileItem item = (FileItem) itr.next(); //检查当前项目是普通表单项目还是上传文件。 if (item.isFormField()) {//如果是普通表单项目,显示表单内容。 String fieldName = item.getFieldName(); if (fieldName.equals("name")) //对应demo1.html中type="text" name="name" out.print("the field name is" + item.getString());//显示表单内容。 out.print("<br>"); } else {//如果是上传文件,显示文件名。 out.print("the upload file name is" + item.getName()); out.print("<br>"); } } } else { out.print("the enctype must be multipart/form-data"); } %> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB18030"> <title>File upload</title> </head> <body> </body> </html> |
结果:
the field name isjeff the upload file name isD:\C语言考试样题\作业题.rar |
示例2
上传两个文件到指定的目录。
demo2.html
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB18030"> <title>File upload</title> </head> <body> <form name="myform" action="demo2.jsp" method="post" enctype="multipart/form-data"> File1:<br> <input type="file" name="myfile"><br> File2:<br> <input type="file" name="myfile"><br> <br> <input type="submit" name="submit" value="Commit"> </form> </body> </html> |
demo2.jsp
<%@ page language="java" contentType="text/html; charset=GB18030" pageEncoding="GB18030"%> <%@ page import="org.apache.commons.fileupload.*"%> <%@ page import="org.apache.commons.fileupload.servlet.*"%> <%@ page import="org.apache.commons.fileupload.disk.*"%> <%@ page import="java.util.*"%> <%@ page import="java.io.*"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <%String uploadPath="D:\\temp"; boolean isMultipart = ServletFileUpload.isMultipartContent(request); if(isMultipart==true){ try{ FileItemFactory factory = new DiskFileItemFactory(); ServletFileUpload upload = new ServletFileUpload(factory); List<FileItem> items = upload.parseRequest(request);//得到所有的文件 Iterator<FileItem> itr = items.iterator(); while(itr.hasNext()){//依次处理每个文件 FileItem item=(FileItem)itr.next(); String fileName=item.getName();//获得文件名,包括路径 if(fileName!=null){ File fullFile=new File(item.getName()); File savedFile=new File(uploadPath,fullFile.getName()); item.write(savedFile); } } out.print("upload succeed"); } catch(Exception e){ e.printStackTrace(); } } else{ out.println("the enctype must be multipart/form-data"); } %> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB18030"> <title>File upload</title> </head> <body> </body> </html> |
结果:
upload succeed |
此时,在"D:\temp"下可以看到你上传的两个文件。
示例3
上传一个文件到指定的目录,并限定文件大小。
demo3.html
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB18030"> <title>File upload</title> </head> <body> <form name="myform" action="demo3.jsp" method="post" enctype="multipart/form-data"> File:<br> <input type="file" name="myfile"><br> <br> <input type="submit" name="submit" value="Commit"> </form> </body> </html> |
demo3.jsp
<%@ page language="java" contentType="text/html; charset=GB18030" pageEncoding="GB18030"%> <%@ page import="org.apache.commons.fileupload.*"%> <%@ page import="org.apache.commons.fileupload.servlet.*"%> <%@ page import="org.apache.commons.fileupload.disk.*"%> <%@ page import="java.util.*"%> <%@ page import="java.io.*"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <% File uploadPath = new File("D:\\temp");//上传文件目录 if (!uploadPath.exists()) { uploadPath.mkdirs(); } // 临时文件目录 File tempPathFile = new File("d:\\temp\\buffer\\"); if (!tempPathFile.exists()) { tempPathFile.mkdirs(); } try { // Create a factory for disk-based file items DiskFileItemFactory factory = new DiskFileItemFactory(); // Set factory constraints factory.setSizeThreshold(4096); // 设置缓冲区大小,这里是4kb factory.setRepository(tempPathFile);//设置缓冲区目录 // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); // Set overall request size constraint upload.setSizeMax(4194304); // 设置最大文件尺寸,这里是4MB List<FileItem> items = upload.parseRequest(request);//得到所有的文件 Iterator<FileItem> i = items.iterator(); while (i.hasNext()) { FileItem fi = (FileItem) i.next(); String fileName = fi.getName(); if (fileName != null) { File fullFile = new File(fi.getName()); File savedFile = new File(uploadPath, fullFile .getName()); fi.write(savedFile); } } out.print("upload succeed"); } catch (Exception e) { e.printStackTrace(); } %> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB18030"> <title>File upload</title> </head> <body> </body> </html> |
示例4
利用Servlet来实现文件上传。
Upload.java
package com.zj.sample; import java.io.File; import java.io.IOException; 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.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; @SuppressWarnings("serial") publicclass Upload extends HttpServlet { private String uploadPath = "D:\\temp"; // 上传文件的目录 private String tempPath = "d:\\temp\\buffer\\"; // 临时文件目录 File tempPathFile; @SuppressWarnings("unchecked") publicvoid doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { try { // Create a factory for disk-based file items DiskFileItemFactory factory = new DiskFileItemFactory(); // Set factory constraints factory.setSizeThreshold(4096); // 设置缓冲区大小,这里是4kb factory.setRepository(tempPathFile);// 设置缓冲区目录 // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); // Set overall request size constraint upload.setSizeMax(4194304); // 设置最大文件尺寸,这里是4MB List<FileItem> items = upload.parseRequest(request);// 得到所有的文件 Iterator<FileItem> i = items.iterator(); while (i.hasNext()) { FileItem fi = (FileItem) i.next(); String fileName = fi.getName(); if (fileName != null) { File fullFile = new File(fi.getName()); File savedFile = new File(uploadPath, fullFile.getName()); fi.write(savedFile); } } System.out.print("upload succeed"); } catch (Exception e) { // 可以跳转出错页面 e.printStackTrace(); } } publicvoid init() throws ServletException { File uploadFile = new File(uploadPath); if (!uploadFile.exists()) { uploadFile.mkdirs(); } File tempPathFile = new File(tempPath); if (!tempPathFile.exists()) { tempPathFile.mkdirs(); } } } |
demo4.html
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB18030"> <title>File upload</title> </head> <body> // action="fileupload"对应web.xml中<servlet-mapping>中<url-pattern>的设置. <form name="myform" action="fileupload" method="post" enctype="multipart/form-data"> File:<br> <input type="file" name="myfile"><br> <br> <input type="submit" name="submit" value="Commit"> </form> </body> </html> |
web.xml
<servlet> <servlet-name>Upload</servlet-name> <servlet-class>com.zj.sample.Upload</servlet-class> </servlet> <servlet-mapping> <servlet-name>Upload</servlet-name> <url-pattern>/fileupload</url-pattern> </servlet-mapping> |
本文出自 “子 孑” 博客,请务必保留此出处http://zhangjunhd.blog.51cto.com/113473/18331
自己根据上面包装了一下 ,把文件上传放入一个FileUpload类的静态方法upload中,方法的形式参数则为HttpServletRequest request和String uploadPath(上传到服务器的路径)
代码如下:
1、FileUpload类
[java] view plain copy
- /*
- * FileUpload
- * @Author TGM
- */
- package com.FileUpload;
- import java.io.File;
- import java.util.Iterator;
- import java.util.List;
- import java.util.logging.Level;
- import java.util.logging.Logger;
- import javax.servlet.http.HttpServletRequest;
- import org.apache.commons.fileupload.FileItem;
- import org.apache.commons.fileupload.FileItemFactory;
- import org.apache.commons.fileupload.FileUploadException;
- import org.apache.commons.fileupload.disk.DiskFileItemFactory;
- import org.apache.commons.fileupload.servlet.ServletFileUpload;
- /**
- *
- * @author TGM
- */
- public class FileUpload {
- /**
- * 静态上传方法
- * @param request HttpServletRequest
- * @param uploadPath String 上传到服务器的文件存放路径
- * @return true 上传成功 false 上传失败
- */
- public static boolean upload(HttpServletRequest request, String uploadPath) {
- boolean isMultipart = ServletFileUpload.isMultipartContent(request);//检查输入请求是否为multipart表单数据。
- boolean flag = false;
- if (isMultipart == true) {
- FileItemFactory factory = new DiskFileItemFactory();//为该请求创建一个DiskFileItemFactory对象,通过它来解析请求。执行解析后,所有的表单项目都保存在一个List中。
- ServletFileUpload upload = new ServletFileUpload(factory);
- List<FileItem> items = null;
- try {
- items = upload.parseRequest(request);
- } catch (FileUploadException ex) {
- Logger.getLogger(FileUpload.class.getName()).log(Level.SEVERE, null, ex);
- }
- Iterator<FileItem> itr = items.iterator();
- while (itr.hasNext()) {
- FileItem item = (FileItem) itr.next();
- //检查当前项目是普通表单项目还是上传文件。
- if (item.isFormField()) {//如果是普通表单项目,显示表单内容。
- String fieldName = item.getFieldName();
- if (fieldName.equals("name")) {//对应demo1.html中type="text" name="name"
- System.out.print("the field name is" + item.getString() + "\n");//显示表单内容。
- }
- } else {//如果是上传文件,显示文件名。
- File fullFile = new File(item.getName());
- File savedFile = new File(uploadPath, fullFile.getName());
- try {
- item.write(savedFile);
- } catch (Exception ex) {
- Logger.getLogger(FileUpload.class.getName()).log(Level.SEVERE, null, ex);
- }
- flag = true;
- System.out.print("the upload file name is" + item.getName() + "\n");
- }
- }
- } else {
- System.out.print("the enctype must be multipart/form-data");
- }
- return flag;
- }
- }
2、index.html(上传表单)
[html] view plain copy
- <!--
- To change this template, choose Tools | Templates
- and open the template in the editor.
- -->
- <!DOCTYPE html>
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=GB18030">
- <title>File upload</title>
- </head>
- <body>
- <form name="myform" action="doUpload2.jsp" method="post"
- enctype="multipart/form-data">
- Your name: <br>
- <input type="text" name="name" size="15"><br>
- File2:<br>
- <input type="file" name="myfile1"><br>
- File2:<br>
- <input type="file" name="myfile2"><br>
- <br>
- <input type="submit" name="submit" value="Commit">
- </form>
- </body>
- </html>
3、doUpload2.jsp 接收处理页面
[plain] view plain copy
- <%--
- Document : doUpload2
- Created on : 2012-9-6, 19:24:20
- Author : TGM
- --%>
- <%@page import="com.FileUpload.FileUpload"%>
- <%@page contentType="text/html" pageEncoding="UTF-8"%>
- <!DOCTYPE html>
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>JSP Page</title>
- </head>
- <body>
- <%
- boolean isUp = FileUpload.upload(request, "D:\\");
- if(isUp){
- out.write("上传成功!");
- } else {
- out.write("上传失败!");
- }
- %>
- </body>
- </html>
commons-fileupload.jar commons-io.jar下载,请猛点!在打开的页面中Search