java怎么实现文件上传

<form action="/upload" method="post" enctype="multipart/form-data">
     <input type="file" name="files">
    <input type="submit" value="上传">
</form>

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws 
ServletException, IOException {
        try {
            // 配置上传参数
            DiskFileItemFactory factory = new DiskFileItemFactory();
            ServletFileUpload upload = new ServletFileUpload(factory);
            // 解析请求的内容提取文件数据
            @SuppressWarnings("unchecked")
            List<FileItem> formItems = upload.parseRequest(request);
 
            // 迭代表单数据
            for (FileItem item : formItems) {
                // 处理不在表单中的字段
                if (!item.isFormField()) {
                    String fileName = item.getName();
                    //定义上传文件的存放路径
                    String path = request.getServletContext().getRealPath("/uploadFiles");
                    //定义上传文件的完整路径
                    String filePath = String.format("%s/%s",path,fileName);
                    File storeFile = new File(filePath);
                    // 在控制台输出文件的上传路径
                    System.out.println(filePath);
                    // 保存文件到硬盘
                    item.write(storeFile);
                }
            }
        } catch (Exception ex) {
 
        }
 
    }