function downloadFile(id) {
	axios.post('/TradingPlatfrom/user/downloadFile', {
		id : id
	}, {
		emulateJSON : false,
		responseType: 'blob'  // 响应数据格式blob
	}).then(function(res) {
		let blob = res.data;
		 let reader = new FileReader();
		 reader.readAsDataURL(blob);
		 reader.onload = (e) => {
		  let a = document.createElement('a');
		  a.download = decodeURI(res.headers.filename); // res.header.filename
														// 后端自己设置下载的文件名
														//也可以取到设置的别的需要的数据
		  a.href = e.target.result;
		  document.body.appendChild(a);
		  a.click();
		  document.body.removeChild(a);
		 }
	}, function(res) {
		console.log(res.status);
	});
}

/**
*	filename文件名字 response 响应对象
*/
    public String downLoad(String filename, HttpServletResponse response) throws UnsupportedEncodingException {
        File file;
        if (filename != null && filename.length() > 0) {
            file = new File(upPath + "/" + filename);
        } else {
            filename = "销售合同.docx";
            file = new File(downPath + "/" + filename);
        }
        if (file.exists()) {
            response.setContentType("application/vnd.ms-excel;charset=UTF-8");
            response.setCharacterEncoding("UTF-8");
            response.setHeader("Content-Disposition",
                    "attachment;fileName=" + java.net.URLEncoder.encode(filename.toString(), "UTF-8"));
            response.setHeader("fileName", java.net.URLEncoder.encode(filename, "UTF-8")); //设置返回下载的文件名称，也可以设置别的需要的数据
            byte[] buffer = new byte[1024];
            FileInputStream fis = null;
            BufferedInputStream bis = null;
            OutputStream os = null;
            try {
                os = response.getOutputStream();
                fis = new FileInputStream(file);
                bis = new BufferedInputStream(fis);
                int i = bis.read(buffer);
                while (i != -1) {
                    os.write(buffer);
                    i = bis.read(buffer);
                }
            } catch (Exception e) {
                e.printStackTrace();
                return "false";
            }
            System.out.println("----------file download---" + filename);
            try {
                bis.close();
                fis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return "true";
    }