获取webapp目录

@RequestMapping("/act/worldcup_schedule_time/imgdownload") 
@ResponseBody 
public String scheduleDownload(HttpServletRequest request, HttpServletResponse response, HttpSession session) { 
    response.setCharacterEncoding("UTF-8"); 
    String downLoadName = "worldcup.jpg"; 
    InputStream input = null; 
    try { 
        request.setCharacterEncoding("UTF-8"); 
        //获取文件的路径 
          String url = session.getServletContext().getRealPath("/") + "resources\\images\\act\\worldcup_merge\\worldcup720.png"; 
        String url = session.getServletContext().getRealPath("/") + "resources/images/act/worldcup_merge/worldcup720.png"; 
        System.out.println(url); 
        File file = new File(url); 
 
 
        input = FileUtils.openInputStream(file); 
        byte[] data = IOUtils.toByteArray(input); 
 
 
        //System.out.println("文件名:"+downLoadName); 
        response.reset(); 
        //设置响应的报头信息(中文问题解决办法) 
        response.setHeader("content-disposition", "attachment;fileName=" + URLEncoder.encode(downLoadName, "UTF-8")); 
        response.addHeader("Content-Length", "" + data.length); 
        response.setContentType("image/png; charset=UTF-8"); 
 
 
        IOUtils.write(data, response.getOutputStream()); 
    } catch (Exception e) { 
        logger.error("下载图片出错"); 
        if (input != null) { 
            IOUtils.closeQuietly(input); 
        } 
    } 
    return null; 
}