springMVC 上传下载文件 

<body>
	<br />
	<br />
	
	<form action="${pageContext.request.contextPath}/user/upload" method="post" enctype="multipart/form-data">
		<input type="file" name="file" /> <input type="submit" value=" 上 传 " />
	</form>

	<br />
	<br />
	<br />
	
    <a href="${pageContext.request.contextPath}/user/download?fileName=${fileUrl}">下载文件</a>

</body>

　　后台代码

/**
 * 
 * @author
 */
@Controller
@RequestMapping("/user")
public class UserController extends BaseController {

    @Autowired
    private UserService userService;

    /**
     * 跳转用户文件上传页面
     * 
     * @return
     */
    @RequestMapping(value = "/uploadPage")
    public String uploadPage() {
        return "/admin/newFile";
    }
    //上传文件
    @RequestMapping(value = "/upload")
    public String upload(@RequestParam(value = "file") MultipartFile file, HttpServletRequest request, ModelMap model) {

        System.out.println("开始");
        // getRealPath("/") 得到的就是你tomcat下webapps下的项目根路径
        String path = request.getSession().getServletContext().getRealPath("upload");

        String fileName = file.getOriginalFilename();
        // String fileName = new Date().getTime()+".jpg";
        System.out.println(path);
        File targetFile = new File(path, fileName);
        if (!targetFile.exists()) {
            targetFile.mkdirs();
        }

        // 保存
        try {
            file.transferTo(targetFile);
        } catch (Exception e) {
            e.printStackTrace();
        }
        model.addAttribute("fileUrl", fileName);

        return "/admin/newFile";
    }
    //下载文件
    @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("upload") + File.separator;
            String temp = request.getParameter("fileName");
            
            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 (Exception e) {
            e.printStackTrace();
        }
        // 返回值要注意，要不然就出现下面这句错误！
        return null;
        
    }


}

　　

posted @ 2017-03-28 15:55  1582277142  阅读(126)  评论(0)  编辑  收藏  举报