安装maven后运行：mvn help:system报错
[ERROR] No plugin found for prefix 'help' in the current project and in the plug
in groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repos
itories [local (C:\Software\maven\repo), central (https://repo.maven.apache.org/
maven2)] -> [Help 1]SpringBoot工程也一直报连不上数据库，这个问题半天我都没解决，然后在发现“金山毒霸”的原因，卸掉重启电脑就好了。
然后安装jar也好了，注意：-Dfile=d:\alidayu-20160607.jar 该路径下要有该jar
mvn install:install-file -Dfile=d:\alidayu-20160607.jar -DgroupId=com.alibaba -DartifactId=alidayu -Dversion=20160607 -Dpackaging=jar