SSM框架之中如何进行文件的上传下载

SSM框架的整合请看我之前的博客：http://www.cnblogs.com/1314wamm/p/6834266.html

现在我们先看如何编写文件的上传下载：你先看你的pom.xml中是否有文件上传的组件包

先看我们写的测试jsp页面：

    <%@ page language="java" contentType="text/html; charset=utf-8"  
        pageEncoding="utf-8"%>  
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
    <html>  
    <head>  
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">  
    <title>文件上传下载</title>  
    </head>  
    <body>  
        <form action="http://localhost:8080/uploadDemo/rest/file/upload" method="post" enctype="multipart/form-data">  
            选择文件:<input type="file" name="file" width="120px">  
            <input type="submit" value="上传">  
        </form>  
        <hr>  
        <form action="http://localhost:8080/uploadDemo/rest/file/down" method="get">  
            <input type="submit" value="下载">  
        </form>  
    </body>  
    </html>

在spring的servlet视图解析器下面定义CommonsMultipartResolver文件解析器，就是加入这个的时候运行项目，如果没有fileuload相关的jar包就会报错。

在controller层写上springmvc上传下载的代码

    package com.baidu;  
    @RequestMapping("file")  
    @Controller  
    public class FileController {  
        /**  
         * 文件上传功能  
         * @param file  
         * @return  
         * @throws IOException   
         */  
        @RequestMapping(value="/upload",method=RequestMethod.POST)  
        @ResponseBody  
        public String upload(MultipartFile file,HttpServletRequest request) throws IOException{  
            String path = request.getSession().getServletContext().getRealPath("upload");  
            String fileName = file.getOriginalFilename();    
            File dir = new File(path,fileName);          
            if(!dir.exists()){  
                dir.mkdirs();  
            }  
            //MultipartFile自带的解析方法  
            file.transferTo(dir);  
            return "ok!";  
        }  
          
        /**  
         * 文件下载功能  
         * @param request  
         * @param response  
         * @throws Exception  
         */  
        @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();  
        }  
    }