<form action=”” method=”post” ?enctype=”multipart/form-data”>
<input type=”file” name=”image”>
<input type=”submit”>
上传的内容，都在请求体中。
2.服务器端：
1）手动获得请求体，需要手动解析。request.getInputStream()
2）使用servlet3.0
3）第三方工具 – apache-commons-fileupload
4）struts2
@WebServlet("/FileUploadServlet")@MultipartConfig ???????//表示支持文件上传，否则获得nullpublic class FileUploadServlet extends HttpServlet { ???private static final long serialVersionUID = 1L;protected void doGet(HttpServletRequest request, HttpServletResponse response) ????????throws ServletException, IOException { ???//1 普通字段 ???String username = request.getParameter("username"); ???System.out.println(username); ???//2 上传字段 ???Part part = request.getPart("image"); ???//2.1 获得文件名 ??????// * IE ????????--> C:\Users\liangtong\Desktop\heima.txt ???// * 其他浏览器 ?--> heima.txt ???String contentDisposition = part.getHeader("Content-Disposition"); ???System.out.println(contentDisposition); ???// * 截取文件名 ???int start = contentDisposition.indexOf("filename=") + 10; ???int end = contentDisposition.length() - 1; ???String fileName = contentDisposition.substring(start, end); ???// * 浏览器兼容 ?-- lastIndexOf() 如果没有获得返回 -1 ???fileName = fileName.substring( fileName.lastIndexOf("\\") + 1); ???System.out.println(fileName); ???//2.2 获得上传文件内容 ???InputStream is = part.getInputStream(); ???//2.3 将流写入到服务器文件中 ???// * 上传目录 ???String dir = this.getServletContext().getRealPath("/WEB-INF/upload"); ???File file = new File(dir , fileName); ???// * 流的对拷 ???FileOutputStream out = new FileOutputStream(file); ???byte[] buf = new byte[1024]; ???int len = -1; ???while( (len = is.read(buf)) != -1 ){ ???????out.write(buf, 0, len); ???} ???out.close(); ???is.close();}protected void doPost(HttpServletRequest request, HttpServletResponse response) ????????throws ServletException, IOException { ???doGet(request, response);}servlet3.0文件上传
原文地址：http://blog.51cto.com/13579086/2083445