Apache FileUpload的两种上传方式阐述及应用
发布时间：2023-07-14 14:37:38 所属栏目：教程 来源：
导读：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
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
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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:www.CuoXIn.com <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <html> <body> <form method="POST" enctype="multipart/form-data" action="traditionalapi.jsp"> File to upload: <input type="file" name="file" size="40"><br/> <input type="submit" value="Press"> to upload the file! </form> </body> </html> //traditionalapi.jsp 复制代码 代码如下:www.CuoXIn.com <%@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<FileItem> items = upload.parseRequest(request); // FileUploadException for(FileItem item : items) { if(item.isFormField()) //regular form field { String name = item.getFieldName(); String value = item.getString(); %> <h1><%=name%> --> <%=value%></h1> <% } 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); %> <h1>upload file <%=uploadedFile.getName()%> done!</h1> <% } } } %> Streaming API上传方式 //fileupload02.htm 复制代码 代码如下:www.CuoXIn.com <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <html> <body> <form method="POST" enctype="multipart/form-data" action="streamingapi.jsp"> File to upload: <input type="file" name="file" size="40"><br/> <input type="submit" value="Press"> to upload the file! </form> </body> </html> //streamingapi.jsp 复制代码 代码如下:www.CuoXIn.com <%@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 { %> <!-- read a FileItemStream's content into a string. --> <h1><%=fieldName%> --> <%=Streams.asString(is)%></h1> <% } 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); %> <h1>upload file <%=uploadedFile.getName()%> done!</h1> <% } } } %> 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. （编辑：聊城站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
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