maven本地倉庫的更新
連網後window+R 輸入cmd回車
輸入maven 版本查看 mvn -v
更新本地倉庫命令 mvn help:system 回車如圖是成功：
失敗報錯如下：
Failed to execute goal org.apache.maven.plugins:maven-help-plugin:3.1.0:system (default-cli) on project standalone-pom: Execution default-cli of goal org.apache.maven.plugins:maven-help-plugin:3.1.0:system failed: Plugin org.apache.maven.plugins:maven-help-plugin:3.1.0 or one of its dependencies could not be resolved: The following artifacts could not be resolved: org.apache.maven:maven-artifact:jar:3.0, org.apache.maven:maven-settings-builder:jar:3.0, org.apache.maven:maven-repository-metadata:jar:3.0, org.apache.maven:maven-model-builder:jar:3.0: Could not transfer artifact org.apache.maven:maven-artifact:jar:3.0 from/to central (https://repo.maven.apache.org/maven2): Connect to repo.maven.apache.org:443 [repo.maven.apache.org/151.101.24.215] failed: Read timed out -> [Help 1]
網查解決辦法：
找到maven的conf->settings.xml修改配置文件
添加如下配置（注意代碼規範格式否則會報如下錯誤）
<mirror>
<id>nexus-aliyun</id>
<mirrorOf>*</mirrorOf>
<name>Nexus aliyun</name>
<url>http://maven.aliyun.com/nexus/content/groups/public</url>
</mirror>
格式不規範，導致報錯如下：
[ERROR] Error executing Maven. [ERROR] 1 problem was encountered while building the effective settings.xml
保證 setting 文件配置正確
