IDEA配置maven中央库

分两步：
STEP 1：配置maven；
STEP 2：配置IDEA。区分默认配置和项目级配置。

STEP 1：maven中央库配置

国内常用的maven库主要是阿里云maven库、华为云maven。

其中阿里云maven库配置如下：

配置文件路径为conf/settings.xml

<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.
     |
    
     -->
        <!-- 阿里云仓库 -->
        <mirror>
            <id>alimaven</id>
            <mirrorOf>central</mirrorOf>
            <name>aliyun maven</name>
            <url>http://maven.aliyun.com/nexus/content/repositories/central/</url>
        </mirror>
    
        <!-- 中央仓库1 -->
        <mirror>
            <id>repo1</id>
            <mirrorOf>central</mirrorOf>
            <name>Human Readable Name for this Mirror.</name>
            <url>http://repo1.maven.org/maven2/</url>
        </mirror>
    
        <!-- 中央仓库2 -->
        <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>nexus-aliyun</id>
             <mirrorOf>*</mirrorOf>
             <name>Nexus aliyun</name>
             <url>http://maven.aliyun.com/nexus/content/groups/public</url>
        </mirror>
  </mirrors>

STEP 2：IDEA配置

打开IDEA，按下Ctrl+Alt+S，进入配置选项界面