Cannot resolve plugin
org.apache.maven.plugins:maven-compiler-plugin:3.8.1

【解决办法】

1. 检查maven路径是否一致

2. 路径一致的话，更改配置文件settings.xml的镜像源。
   添加代码到 <mirrors>

<!-- 阿里镜像 -->
<mirror><id>alimaven</id><mirrorOf>central</mirrorOf><name>aliyun maven</name><url>http://maven.aliyun.com/nexus/content/repositories/central/</url>
</mirror>
<mirror><id>alimaven</id><name>aliyun maven</name><url>http://maven.aliyun.com/nexus/content/groups/public/</url><mirrorOf>central</mirrorOf>
</mirror>
<mirror><id>central</id><name>Maven Repository Switchboard</name><url>http://repo1.maven.org/maven2/</url><mirrorOf>central</mirrorOf>
</mirror>
<mirror><id>repo2</id><mirrorOf>central</mirrorOf><name>Human Readable Name for this Mirror.</name><url>http://repo2.maven.org/maven2/</url>
</mirror>
<mirror><id>ibiblio</id><mirrorOf>central</mirrorOf><name>Human Readable Name for this Mirror.</name><url>http://mirrors.ibiblio.org/pub/mirrors/maven2/</url>
</mirror>
<mirror><id>jboss-public-repository-group</id><mirrorOf>central</mirrorOf><name>JBoss Public Repository Group</name><url>http://repository.jboss.org/nexus/content/groups/public</url>
</mirror>
<mirror><id>google-maven-central</id><name>Google Maven Central</name><url>https://maven-central.storage.googleapis.com</url><mirrorOf>central</mirrorOf>
</mirror>
<!-- 中央仓库在中国的镜像 -->
<mirror><id>maven.net.cn</id><name>oneof the central mirrors in china</name><url>http://maven.net.cn/content/groups/public/</url><mirrorOf>central</mirrorOf>
</mirror>

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