FileUpload的使用案例
文件上传 1、www.apache.org下载commons fileupload 和 commons io 2、创建jsp并附上如下代码 <%@ page language="java" contentType="text/html; charset=GB18030" pageEncoding="GB18030"%> <% String strId = request.getParameter("id"); int id = 0; if(strId == null && strId.trim().equals("")){ out.println("你选择的商品有错!"); return; } id = Integer.parseInt(strId); %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>index.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body> <form action="../FileUpload" method="post" enctype="multipart/form-data" name="form1"> <input type="hidden" name="id" value="<%=id %>"> <input type="file" name="file"> <input type="submit" name="Submit" value="upload"> </form> <br> <br> <form name="uploadform" method="POST" action="./servlet/FileUpload" ENCTYPE="multipart/form-data"> <table border="1" width="450" cellpadding="4" cellspacing="2" bordercolor="#9BD7FF"> <tr><td width="100%" colspan="2"> 文件1:<input name="x" size="40" type="file"> </td></tr> <tr><td width="100%" colspan="2"> 文件2:<input name="y" size="40" type="file"> </td></tr> <tr><td width="100%" colspan="2"> 文件3:<input name="z" size="40" type="file"> </td></tr> </table> <br/><br/> <table> <tr><td align="center"><input name="upload" type="submit" value="开始上传"/></td></tr> </table> </form> </body> </html> 3、直接在项目下创建servlet并附上如下代码 package com.cuijun.shopping.servlet; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.*; import java.util.*; import java.util.regex.*; import java.io.*; import org.apache.commons.fileupload.servlet.*; import org.apache.commons.fileupload.disk.DiskFileItemFactory; public class FileUpload extends HttpServlet { String uploadPath = ""; @Override public void init(ServletConfig config) throws ServletException { uploadPath = config.getInitParameter("uploadPath"); } int id = -1; public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { res.setContentType("text/html; charset=GB18030"); PrintWriter out = res.getWriter(); System.out.println(req.getContentLength()); System.out.println(req.getContentType()); DiskFileItemFactory factory = new DiskFileItemFactory(); // maximum size that will be stored in memory factory.setSizeThreshold(4096); // the location for saving data that is larger than getSizeThreshold() factory.setRepository(new File("d:\\temp\\")); ServletFileUpload upload = new ServletFileUpload(factory); // maximum size before a FileUploadException will be thrown upload.setSizeMax(1000000); try { List fileItems = upload.parseRequest(req); // assume we know there are two files. The first file is a small // text file, the second is unknown and is written to a file on // the server Iterator iter = fileItems.iterator(); // 正则匹配,过滤路径取文件名 String regExp = ".+\\\\(.+)$"; // 过滤掉的文件类型 String[] errorType = { ".exe", ".com", ".cgi", ".asp" }; Pattern p = Pattern.compile(regExp); while (iter.hasNext()) { FileItem item = (FileItem) iter.next(); // 忽略其他不是文件域的所有表单信息 if (item.isFormField()){ if(item.getFieldName().equals("id")){ id = Integer.parseInt(item.getString()); } } if (!item.isFormField()) { String name = item.getName(); long size = item.getSize(); if ((name == null || name.equals("")) && size == 0) continue; Matcher m = p.matcher(name); boolean result = m.find(); if (result) { for (int temp = 0; temp < errorType.length; temp++) { if (m.group(1).endsWith(errorType[temp])) { throw new IOException(name + ": wrong type"); } } try { // 保存上传的文件到指定的目录 // 在下文中上传文件至数据库时,将对这里改写 //item.write(new File("d:\\" + m.group(1))); item.write(new File(uploadPath + id + ".jpg")); out.print(name + " " + size + "<br>"); } catch (Exception e) { out.println(e); } } else { throw new IOException("fail to upload"); } } } } catch (IOException e) { out.println(e); } catch (FileUploadException e) { out.println(e); } // 保存上传的文件到指定的目录 // 在下文中上传文件至数据库时,将对这里改写 } } 4、注意代码中的路径问题。千万小心。 1、路径中\\代表\。不要写成//。 2、路径后面不要忘记添加\\。 5、接受id。 1、先定义int id = -1; 2、判断接受的域是正常域if (item.isFormField()){ if(item.getFieldName().equals("id")){ id = Integer.parse(item.getString()); } } 3、把上传的文件写到内存item.write(new File(uploadPath + id + ".jpg")); 6、修改WEB-INF下的配置文件 1、添加<init-param> <param-name>uploadPath</param-name> <param-value>D:\\web\\Shopping\\WebContent\\image\\product\\</param-value> </init-param> 2、在servlet中重写init方法String uploadPath = ""; @Override public void init(ServletConfig config) throws ServletException { uploadPath = config.getInitParameter("uploadPath"); } 7、Over!