一、异常内容

使用了Java前后端分离项目（Logan框架），前端Axios发送跨域请求时，Chrome提示了报错如下

Access to XMLHttpRequest at 
'http://localhost:3000/luckylog/luckylog/latest.json' from origin 
'http://localhost:30000' has been blocked by CORS policy: 
The value of the 'Access-Control-Allow-Origin' header 
in the response must not be the wildcard '*' 
when the request's credentials mode is 'include'. 
The credentials mode of requests initiated by the XMLHttpRequest 
is controlled by the withCredentials attribute.