servlet3.0 getPart()与getParts()获取上传文件

来源：互联网发布：opencv2.4.4 sift算法编辑：程序博客网时间：2024/06/04 18:10

需求： servlet3.0以上，就是tomcat7.0以上,web.xml->web-app->version 3.0以上, 不需要引入其它的jar包

Servlet类需要添加注释@MultipartConfig, 必要，否则request.getPart()会为null

@MultipartConfigpublic class FileServlet extends HttpServlet {        public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmssSSS");        //文件存放目录        String mypath = this.getClass().getClassLoader().getResource("/../../").getPath() + "upload";        File file = new File(mypath );        if(!file.exists()){            file.mkdir();        }        String filename = format.format(new Date());        // multipart/form-data         if (ServletFileUpload.isMultipartContent(request)) {            Part part = request.getPart("ff");            if(part == null){                return;            }            String headerfNValue = part.getHeader("content-disposition");            if("".equals(headerfNValue.trim()){                return ;            }            //headerfNValue = [filename="xxxx.xxx"]            String valueKey = "filename=\"";            int s = headerfNValue.indexOf(valueKey );            if(s < 0){                return;            }            String originalfilename = headerfNValue.substring(s + valueKey.length(), headerfNValue.length()-1);;            String suffix =  originalfilename.substring(originalfilename.lastIndexOf("."));            if(".jpg|.jpeg|.jpe|.jfif|.png|.gif|.bmp|.dib|.tif|.tiff".indexOf(suffix) < 0){                 return;            }                        filename += suffix;                    InputStream input = part.getInputStream();                    file = new File(mypath + filename);            if(!file.exists()){                file.createNewFile();            }                    FileOutputStream fos = new FileOutputStream(file);            int size = 0;            byte[] buffer = new byte[1024];            while ((size = input.read(buffer)) != -1) {                fos.write(buffer, 0, size);            }            fos.close();            input.close();         }    }}

getParts() 就是多个Part ,for出来就可以
关于 @MultipartConfig 注释：
@MultipartConfig(location = "/upload", maxFileSize = 1024 * 1024 * 50)
设置了location 就是文件的保存路径 , 确认Part的filename不为空后，可以直接写入, 可以省去后面的文件流操作
......
filename += suffix;
part.write(filename);

前端页面：
<form action="" method ="post" enctype="multipart/form-data">
<input type="file" name="ff" />
<input type="submit" value="go" />
</form>

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