【下载文档:  Apache_FileUpload的两种上传方式介绍及应用.txt 】

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Apache FileUpload的两种上传方式介绍及应用
环境： tomcat5.6 commmons-fileupload-1.3.jar commmons-io-2.4.jar JSP 编码：UTF-8 临时文件夹：fileupload/tmp相对于网站根目录 上传文件保存位置：fileupload Traditional API上传方式 //fileload01.htm 复制代码 代码如下:

File to upload:
to upload the file!

//traditionalapi.jsp 复制代码 代码如下: <%@page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8" language="java"%> <%@page import="java.io.File"%> <%@page import="java.util.List"%> <%@page import="org.apache.commons.fileupload.*"%> <%@page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%> <%@page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%> <% request.setCharacterEncoding("UTF-8"); // file less than 10kb will be store in memory, otherwise in file system. final int threshold = 10240; final File tmpDir = new File(getServletContext().getRealPath("/") + "fileupload" + File.separator + "tmp"); final int maxRequestSize = 1024 * 1024 * 4; // 4MB // Check that we have a file upload request if(ServletFileUpload.isMultipartContent(request)) { // Create a factory for disk-based file items. FileItemFactory factory = new DiskFileItemFactory(threshold, tmpDir); // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); // Set overall request size constraint. upload.setSizeMax(maxRequestSize); List items = upload.parseRequest(request); // FileUploadException for(FileItem item : items) { if(item.isFormField()) //regular form field { String name = item.getFieldName(); String value = item.getString(); %>

<%=name%> --> <%=value%>

<% } else { //file upload String fieldName = item.getFieldName(); String fileName = item.getName(); File uploadedFile = new File(getServletContext().getRealPath("/") + "fileupload" + File.separator + fieldName + "_" + fileName); item.write(uploadedFile); %>

upload file <%=uploadedFile.getName()%> done!

<% } } } %> Streaming API上传方式 //fileupload02.htm 复制代码 代码如下:

File to upload:
to upload the file!

//streamingapi.jsp 复制代码 代码如下: <%@page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8" language="java"%> <%@page import="java.io.*"%> <%@page import="java.util.List"%> <%@page import="org.apache.commons.fileupload.*"%> <%@page import="org.apache.commons.fileupload.util.Streams"%> <%@page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%> <% request.setCharacterEncoding("UTF-8"); // Check that we have a file upload request if(ServletFileUpload.isMultipartContent(request)) { // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(); // Parse the request FileItemIterator iter = upload.getItemIterator(request); while(iter.hasNext()) { FileItemStream item = iter.next(); String fieldName = item.getFieldName(); InputStream is = item.openStream(); if(item.isFormField()) //regular form field { %>

<%=fieldName%> --> <%=Streams.asString(is)%>

<% } else { //file upload String fileName = item.getName(); File uploadedFile = new File(getServletContext().getRealPath("/") + "fileupload" + File.separator + fieldName + "_" + fileName); OutputStream os = new FileOutputStream(uploadedFile); // write file to disk and close outputstream. Streams.copy(is, os, true); %>

upload file <%=uploadedFile.getName()%> done!

<% } } } %> Traditional API vs Streaming API Streaming API上传速度相对较快。因为它是利用内存保存上传的文件，节省了传统API将文件写入临时文件带来的开销。 可参考： http://stackoverflow.com/questions/11620432/apache-commons-fileupload-streaming-api This page describes the traditional API of the commons fileupload library. The traditional API is a convenient approach. However, for ultimate performance, you might prefer the faster Streaming API. http://commons.apache.org/proper/commons-fileupload/using.html