ssm 上传和下载

╰+哭是因爲堅強的太久メ 2022-06-08 13:35 127阅读 0赞

1 导入jar

<dependencies>
            <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>2.2</version>
            </dependency>

2 配置springmvc

3 上传代码

@RequestMapping("upload")
        public String upload(MultipartFile file,HttpServletRequest request)
        {
            String fileName = file.getOriginalFilename();    
            File dir = new File("e:/temp/",fileName);          
            if(!dir.exists()){  
                dir.mkdirs();  
            }  
            //MultipartFile自带的解析方法 
            try {
                file.transferTo(dir);
            } catch (IllegalStateException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } 
    // DispatcherServlet 
            return "index";
        }
    
        @RequestMapping("hello")
        public String index(String page)
        {
            return "index";
        }

4 下载代码

@RequestMapping("down")  
        public void down(HttpServletRequest request,HttpServletResponse response) throws Exception{  
            //模拟文件，myfile.txt为需要下载的文件 
            String fileName = request.getSession().getServletContext().getRealPath("upload")+"/myfile.txt";  
            //获取输入流 
            InputStream bis = new BufferedInputStream(new FileInputStream(new File(fileName)));  
            //假如以中文名下载的话 
            String filename = "下载文件.txt";  
            //转码，免得文件名中文乱码 
            filename = URLEncoder.encode(filename,"UTF-8");  
            //设置文件下载头 
            response.addHeader("Content-Disposition", "attachment;filename=" + filename);    
            //1.设置文件ContentType类型，这样设置，会自动判断下载文件类型 
            response.setContentType("multipart/form-data");   
            BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());  
            int len = 0;  
            while((len = bis.read()) != -1){  
                out.write(len);  
                out.flush();  
            }  
            out.close();  
        }

5丶 jsp页面上传时注意给from加

method="post" enctype="multipart/form-data"

这两个关键

6丶 下载的时候需要注意有没有这个文件夹 和文件 没有的话就创建一个  
并且把页面改成 method=“ get”