SpringMVC实现文件的上传和下载

怼烎@ 2024-04-18 16:56 78阅读 0赞

# 1、文件上传 #

### 1.1 导入依赖 ###

<dependency>
        <groupId>commons-fileupload</groupId>
        <artifactId>commons-fileupload</artifactId>
        <version>1.3.1</version>
    </dependency>
    	
    <dependency>
        <groupId>commons-io</groupId>
        <artifactId>commons-io</artifactId>
        <version>2.4</version>
    </dependency>

### 1.2 设置文件上传解析器 ###

**bean的名字是固定的:multipartResolver**

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
            
            <property name="maxUploadSize" value="#{1024*1024}"/>
        </bean>

### 1.3 jsp页面 ###

### 1.4 新建文件上传的Controller类 ###

@Controller
    public class UploadFile {
        /*文件上传*/
        @Autowired
        private ServletContext servletContext;
    
        @RequestMapping("/upload")
        public ModelAndView file(String filename, MultipartFile file) throws Exception{
            /*把文件对象以流形式，写入到目标文件夹中（只能保存到target文件夹中）*/
            String realPath = servletContext.getRealPath("/");
            /*自定义保存文件的文件名*/
            String path = realPath + new Date().getTime() + file.getOriginalFilename();
            /*加载*/
            File newfile = new File(path);
            /*执行*/
            file.transferTo(newfile);
            return null;
        }
    }

# 2、文件下载 #

### 2.1 jsp页面 ###

<fieldset>
        <legend>文件下载</legend>
        <form action="/download" method="post">
            输入要下载的文件名<input name="filename"/><br/>
            <input type="submit" value="提交">
        </form>
    </fieldset>

### 2.2 新建文件下载的Controller类 ###

@Controller
    public class DownloadFile {
        /*文件下载*/
        @Autowired
        private ServletContext context;
    
        @RequestMapping("/download")
        public ModelAndView download(String filename, HttpServletResponse response) throws Exception{
    
            /*设置文件下载的响应头*/
            response.setContentType("application/x-msdownload");
    
            response.setHeader("Content-Disposition","attachment;filename="+filename);
    
    
            //设置图片所在路径
            String realpath = context.getRealPath("/");
            //执行
            Files.copy(Paths.get(realpath,filename),response.getOutputStream());
    
            return null;
        }
    
    }

# 3、注意： #

1.SpringMVC上传必须配置文件上传解析器"org.springframework.web.multipart.commons.CommonsMultipartResolver",解析器的id必须为"multipartResolver"  
2.做文件上传的form表单的提交方式必须为"post",同时表单的提交类型为:“multipart/form-data”  
3.控制器的方法可以使用MultipartFile对象,接收上传的文件  
4.SpringMVC没有对文件的下载做封装