解决方法一：https://blog.csdn.net/u014589116/article/details/109324430
部署一个nginx或者nodejs服务器
Access to XMLHttpRequest at from origin 'null' has been blocked by CORS policy:cross origin requests are only supported for protocol schemes:http,data,chrome-extension,edge,https,chrome-untrusted.
解决方法二：把打包后的项目放到tomcat的webapps下
