解决办法:
通过
Helper->Show Log in Explorer
查看Idea的日志,就可以发现具体的原因
Delete the entire .m2/repository folder manually, and then update your Maven project again.
1、Intellij Idea Maven ‘cannot reconnect’ error
https://stackoverflow.com/questions/30615067/intellij-idea-maven-cannot-reconnect-error
2、Idea Maven 报错 Cannot reconnect