解決Maven外掛無法下載Cannot resolve plugin org.apache.maven.plugins:maven-clean-plugin:2.5

首先檢查一下你的IDEA中Maven的配置是否一致。

如果這裡沒有問題，那多半就是倉庫映象的問題了，這裡提供多個映象，新增到maven的配置檔案裡即可。

<mirrors>
    <!-- mirror
     | Specifies a repository mirror site to use instead of a given repository. The repository that
     | this mirror serves has an ID that matches the mirrorOf element of this mirror. IDs are used
     | for inheritance and direct lookup purposes, and must be unique across the set of mirrors.
     |
    <mirror>
      <id>mirrorId</id>
      <mirrorOf>repositoryId</mirrorOf>
      <name>Human Readable Name for this Mirror.</name>
	  http://maven.aliyun.com/nexus/content/groups/public/
      <url>http://my.repository.com/repo/path</url>
    </mirror>
     -->
		<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>
        <!-- 中央倉庫在中國的映象 -->
        <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>
  </mirrors>