SpringMvc文件上传和下载

客官°小女子只卖身不卖艺 2022-07-17 00:11 298阅读 0赞

最近博主在做SpringMvc文件上传和下载的功能实现,上网查了很多资料很多都不太符合理想,找啊找,终于找到一个可以用的,然后再此基础上,我加以改进,可以支持多文件上传,而且代码非常精简,大家可以看看.

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyOTUzMDc5_size_16_color_FFFFFF_t_70][]          http://pan.baidu.com/s/1o7Oo4NC 原码下载

首先需要导入jar包:

![Center][]

然后,在applicatinContext.xml中添加上传和下载的配置文件,如下:

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">   
               
            <property name="maxUploadSize" value="200000"/>   
        </bean>   
          
           
        <bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">   
            <property name="exceptionMappings">   
                <props>   
                       
                    <prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">error</prop>   
                </props>   
            </property>   
        </bean>

好了,最基础的配置就好了,接下来jsp页面:upload.jsp

Controller中对应的java代码:

@RequestMapping("/upload.do")
    	public String upload(@RequestParam MultipartFile[] myfiles, HttpServletRequest request) throws IOException {
    		for (MultipartFile file : myfiles) {
    			// 此处MultipartFile[]表明是多文件,如果是单文件MultipartFile就行了
    			if (file.isEmpty()) {
    				System.out.println("文件未上传!");
    			} else {
    				// 得到上传的文件名
    				String fileName = file.getOriginalFilename();
    				// 得到服务器项目发布运行所在地址
    				String path1 = request.getSession().getServletContext().getRealPath("image") + File.separator;
    				// 此处未使用UUID来生成唯一标识,用日期做为标识
    				String path = path1 + new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()) + fileName;
    				// 查看文件上传路径,方便查找
    				System.out.println(path);
    				// 把文件上传至path的路径
    				File localFile = new File(path);
    				file.transferTo(localFile);
    			}
    		}
    		return "uploadSuccess";
    	}

这样就可以把网页上选择的图片上传上去了

![Center 1][]

![Center 2][]

下载成功了!

### 文件下载 ###

(文件下载我是参照网上一位前辈的,在此注明他的博客网址:http://my.oschina.net/u/1394615/blog/311307):

download.jsp:此处为了测试,我直接把文件名当作参数传过去:

Controller:

@RequestMapping("/download")
    	public String download(String fileName, HttpServletRequest request, HttpServletResponse response) {
    		response.setCharacterEncoding("utf-8");
    		response.setContentType("multipart/form-data");
    		response.setHeader("Content-Disposition", "attachment;fileName=" + fileName);
    		try {
    			String path = request.getSession().getServletContext().getRealPath("image") + File.separator;
    			InputStream inputStream = new FileInputStream(new File(path + fileName));
    
    			OutputStream os = response.getOutputStream();
    			byte[] b = new byte[2048];
    			int length;
    			while ((length = inputStream.read(b)) > 0) {
    				os.write(b, 0, length);
    			}
    
    			// 这里主要关闭。
    			os.close();
    
    			inputStream.close();
    		} catch (FileNotFoundException e) {
    			e.printStackTrace();
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    		// 返回值要注意，要不然就出现下面这句错误！
    		// java+getOutputStream() has already been called for this response
    		return null;
    	}

![Center 3][]![Center 4][]

OK,springmvc的上传下载就完成了!

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyOTUzMDc5_size_16_color_FFFFFF_t_70]: /images/20220717/b592896818fa417b8b88af0ea8ca9677.png
[Center]: /images/20220717/bd5f0aeee5ee466696e39afdb0d55f85.png
[Center 1]: /images/20220717/c7ab7d60bbcc443c87104fc8c21da00d.png
[Center 2]: /images/20220717/1c9559e31d7a4e85bca3b496ca417a58.png
[Center 3]: https://img-blog.csdn.net/20160823141618928?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 4]: /images/20220717/7c991986d5b14abe8567cdee0dd4390f.png