settings.xml 文件是 Maven 配置的核心文件之一，主要用于配置用户级别的设置、镜像、仓库等。
通常位于用户主目录下的 .m2 文件夹中（全局配置则位于 Maven 安装目录下的 conf 文件夹中）。

<?xml version="1.0" encoding="UTF-8"?>

<settings xmlns="http://maven.apache.org/SETTINGS/1.2.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 https://maven.apache.org/xsd/settings-1.2.0.xsd">
          
  <!-- localRepository  
   | 本地仓库，默认路径为 ~/.m2/repository
   | Default: ${user.home}/.m2/repository
  -->
  <localRepository>/path/to/local/repo</localRepository>

  <!-- interactiveMode
   | 是否使用交互模式，默认为true
   | Default: true
  -->
  <interactiveMode>true</interactiveMode>

  <!-- offline
   | 是否使用离线模式，默认为false
   | Default: false
  -->
  <offline>false</offline>

  <!-- pluginGroups
   | 插件组ID和版本映射
   | 在命令行使用插件时可以省略组ID
  -->
  <pluginGroups>
    <pluginGroup>com.your.plugins</pluginGroup>
  </pluginGroups>

  <!-- proxies
   | 代理配置
  -->
  <proxies>
    <proxy>
      <id>optional</id>
      <active>true</active>
      <protocol>http</protocol>
      <username>proxyuser</username>
      <password>proxypass</password>
      <host>proxy.host.net</host>
      <port>80</port>
      <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>
  </proxies>

  <!-- servers
   | 服务器认证信息
   | 需要注意的是此处的服务器认证信息和maven私服搭建有关
  -->
  <servers>
    <server>
      <id>deploymentRepo</id>
      <username>repouser</username>
      <password>repopwd</password>
    </server>
 
    <server>
      <id>siteServer</id>
      <privateKey>/path/to/private/key</privateKey>
      <passphrase>optional; leave empty if not used.</passphrase>
    </server>
  </servers>

  <!-- mirrors
   | 镜像配置
  -->
  <mirrors>
    <mirror>
      <id>mirrorId</id>
      <mirrorOf>repositoryId</mirrorOf>
      <name>Human Readable Name for this Mirror.</name>
      <url>http://my.repository.com/repo/path</url>
    </mirror>

    <mirror>
      <id>maven-default-http-blocker</id>
      <mirrorOf>external:http:*</mirrorOf>
      <name>Pseudo repository to mirror external repositories initially using HTTP.</name>
      <url>http://0.0.0.0/</url>
      <blocked>true</blocked>
    </mirror>
  </mirrors>

  <!-- profiles
   | 仓库配置
  -->
  <profiles>
    <profile>
      <id>jdk-1.4</id>

      <activation>
        <jdk>1.4</jdk>
      </activation>

      <repositories>
        <repository>
          <id>jdk14</id>
          <name>Repository for JDK 1.4 builds</name>
          <url>http://www.myhost.com/maven/jdk14</url>
          <layout>default</layout>
          <snapshotPolicy>always</snapshotPolicy>
        </repository>
      </repositories>
    </profile>


    <profile>
      <id>env-dev</id>

      <activation>
        <property>
          <name>target-env</name>
          <value>dev</value>
        </property>
      </activation>

      <properties>
        <tomcatPath>/path/to/tomcat/instance</tomcatPath>
      </properties>
    </profile>
  </profiles>

  <!-- activeProfiles
   | 激活的profile
  -->
  <activeProfiles>
    <activeProfile>alwaysActiveProfile</activeProfile>
    <activeProfile>anotherAlwaysActiveProfile</activeProfile>
  </activeProfiles>

</settings>