/**
     * 下载模板文件
     * @author cq
     */
        @RequestMapping("/downloadExcel.do")    
        public ResponseEntity<byte[]> download() throws IOException {    
            String path=servletContext.getRealPath("/")+"uploadFiles/file/purchase_modal.xls";  
            File file=new File(path);  
            HttpHeaders headers = new HttpHeaders();    
            String fileName=new String("批量导入模板.xls".getBytes("UTF-8"),"iso-8859-1");//为了解决中文名称乱码问题  
            headers.setContentDispositionFormData("attachment", fileName);   
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);   
            return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.CREATED);    
        }