执行mvn clean package 提示如下
[ERROR] Plugin org.apache.maven.plugins:maven-clean-plugin:2.5 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-clean-plugin:jar:2.5: Could not transfer artifact org.apache.maven.plugins:maven-clean-plugin:pom:2.5 from/to central (https://repo.maven.apache.org/maven2): Received fatal alert: protocol_version -> [Help 1]
解决办法参考：
https://blog.csdn.net/LD799989470LD/article/details/80257725
直接加个mirror就好了，我之前试过加别的mirror， 不好使， 这个可以！