添加代理

添加这三个代理到nexus上

<mirror> 
        <id>offical</id> 
        <name>Maven Official Repository</name> 
        <url>http://repo1.maven.org/maven2</url> 
        <mirrorOf>central</mirrorOf> 
</mirror>
<mirror> 
        <id>oss.sonatype.org</id> 
        <name>Maven Official Repository</name> 
        <url>https://oss.sonatype.org/content/repositories/</url> 
        <mirrorOf>central</mirrorOf> 
</mirror>
<mirror> 
        <id>sonatype</id> 
        <name>sonatype</name> 
        <url>http://repository.sonatype.org/content/groups/public</url> 
        <mirrorOf>central</mirrorOf> 
</mirror>
<mirror>
        <id>alimaven</id>
        <name>aliyun maven</name>
        <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
        <mirrorOf>central</mirrorOf>