文件名称：Apache Commons fileUpload实现文件上传
文件大小：10KB
文件格式：TXT
更新时间：2015-10-15 08:34:04
Commons fileUpload
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:
<input type="text" name="name" size="15"><br>
File:
<input type="file" name="myfile"><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.*"%>
<%
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
");
} else {//如果是上传文件，显示文件名。
out.print("the upload file name is" + item.getName());
out.print("
");
}
}
} 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:
<input type="file" name="myfile"><br>
File2:
<input type="file" name="myfile"><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.*"%>
<%String uploadPath="D:\\\\temp";
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
if(isMultipart==true){
try{
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
List
<input type="file" name="myfile"><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.*"%>
<%
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
<input type="file" name="myfile"><br>
<input type="submit" name="submit" value="Commit">
</form>
</body>
</html>
web.xml