Spring MVC实现文件上传和下载

本文实例为大家分享了Spring MVC实现文件上传和下载的具体代码，供大家参考，具体内容如下

1、导入主要依赖

<!--文件上传--><dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version></dependency><!--servlet-api导入高版本的--><dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>4.0.1</version></dependency>

2、配置bean：multipartResolver（注：此bena的id必须为：multipartResolver ， 否则上传文件会报400的错误！）

<!--文件上传配置--><bean class='org.springframework.web.multipart.commons.CommonsMultipartResolver'> <!-- 请求的编码格式，必须和jSP的pageEncoding属性一致，以便正确读取表单的内容， 默认为ISO-8859-1 --> <property name='defaultEncoding' value='utf-8'/> <!-- 上传文件大小上限，单位为字节（10485760=10M） --> <property name='maxUploadSize' value='10485760'/> <property name='maxInMemorySize' value='40960'/></bean>

3、index.jsp

4、Controller

@RestControllerpublic class FileController { //@RequestParam('file') 将name=file控件得到的文件封装成 CommonsMultipartFile 对象 //批量上传 CommonsMultipartFile 则为数组即可 @RequestMapping('/upload') public String fileUpload(@RequestParam('file') CommonsMultipartFile file, HttpServletRequest request) throws IOException {//获取文件名 : file.getOriginalFilename();String uploadFileName = file.getOriginalFilename();//如果文件名为空，直接回到首页！if (''.equals(uploadFileName)) { return 'redirect:/index.jsp';}System.out.println('上传文件名 : ' + uploadFileName);//上传路径保存设置String path = request.getServletContext().getRealPath('/upload');//如果路径不存在，创建一个File realPath = new File(path);if (!realPath.exists()) { realPath.mkdir();}System.out.println('上传文件保存地址：' + realPath);InputStream is = file.getInputStream(); //文件输入流OutputStream os = new FileOutputStream(new File(realPath, uploadFileName)); //文件输出流//读取写出int len = 0;byte[] buffer = new byte[1024];while ((len = is.read(buffer)) != -1) { os.write(buffer, 0, len); os.flush();}os.close();is.close();return 'redirect:/index.jsp'; } /* * 采用file.Transto 来保存上传的文件 */ @RequestMapping('/upload2') public String fileUpload2(@RequestParam('file') CommonsMultipartFile file, HttpServletRequest request) throws IOException {//上传路径保存设置String path = request.getServletContext().getRealPath('/upload');File realPath = new File(path);if (!realPath.exists()) { realPath.mkdir();}System.out.println('上传文件保存地址：' + realPath);//通过CommonsMultipartFile的方法直接写文件（注意这个时候）file.transferTo(new File(realPath + '/' + file.getOriginalFilename()));return 'redirect:/index.jsp'; }}

index.jsp

Controller

@RequestMapping(value = '/download')public String downloads(HttpServletResponse response, HttpServletRequest request) throws Exception { //要下载的图片地址 String path = request.getServletContext().getRealPath('/upload'); String fileName = '基础语法.jpg'; //1、设置response 响应头 response.reset(); //设置页面不缓存,清空buffer response.setCharacterEncoding('UTF-8'); //字符编码 response.setContentType('multipart/form-data'); //二进制传输数据 //设置响应头 response.setHeader('Content-Disposition', 'attachment;fileName=' + URLEncoder.encode(fileName, 'UTF-8')); File file = new File(path, fileName); //2、 读取文件--输入流 InputStream input = new FileInputStream(file); //3、 写出文件--输出流 OutputStream out = response.getOutputStream(); byte[] buff = new byte[1024]; int index = 0; //4、执行 写出操作 while ((index = input.read(buff)) != -1) {out.write(buff, 0, index);out.flush(); } out.close(); input.close(); return null;}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持好吧啦网。