Commons FileUpload文件上传组件

Java实现的文件上传组件有好几种，其中最为“官方”的要数Apache Commons库中的FileUpload了吧。

页面

<form method="POST" enctype="multipart/form-data" action="fup.cgi">

  File to upload: <input type="file" name="upfile"><br/>

  Notes about the file: <input type="text" name="note"><br/>

  <br/>

  <input type="submit" value="Press"> to upload the file!

</form>

后台java，可在servlet或者struts的action中处理

// Create a factory for disk-based file items

        DiskFileItemFactory factory = new DiskFileItemFactory();

        // Configure a repository (to ensure a secure temp location is used)

        ServletContext servletContext = this.getServlet().getServletContext();

        File repository = (File) servletContext.getAttribute("javax.servlet.context.tempdir");

        factory.setRepository(repository);

        // Create a new file upload handler

        ServletFileUpload upload = new ServletFileUpload(factory);

        // Parse the request

        try {

            List<FileItem> items = upload.parseRequest(request);

            // Process the uploaded items

            Iterator<FileItem> iter = items.iterator();

            while (iter.hasNext()) {

                FileItem item = iter.next();

                if (item.isFormField()) {

                    //processFormField(item);

                    } else {

                        //processUploadedFile(item);

                        String fieldName = item.getFieldName();

                        String fileName = item.getName();

                        String contentType = item.getContentType();

                        boolean isInMemory = item.isInMemory();

                        long sizeInBytes = item.getSize();

                        File uploadedFile = new File("temp.xls");

                        item.write(uploadedFile);

}}

以上代码作用是将一个文件（这里是一个excel）从客户端的浏览器通过form表单上传到服务器，服务器端的FileUpload将它保存到temp.xls中。

参考： http://commons.apache.org/proper/commons-fileupload/