个人简介：Java领域新星创作者；阿里云技术博主、星级博主、专家博主；正在Java学习的路上摸爬滚打，记录学习的过程~
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学习社区：进去逛一逛~

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一、下载Maven核心程序

• 通过官方渠道，下载Maven压缩包，官网🔗：maven.apache.org

…

• 进入官网后，选择Download(下载)选项，安装最新版本的压缩包

…

• 将压缩包放置到自己喜欢的目录下，解压：

注意:文件夹目录要求 非中文、无空格。

👇

…

• 加压后，文件的内容目录如下：

其中，Maven核心的配置文件是conf目录下的settings.xml文件

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二、设置本地仓库

⚪为什么

• Maven本地仓库是有默认值的，我们可以从conf\settings.xml文件下找到关于默认本地仓库的描述：

  <!-- localRepository
   | The path to the local repository maven will use to store artifacts.
   |
   | Default: ${user.home}/.m2/repository
  <localRepository>/path/to/local/repo</localRepository>
  -->

我们从配置文件的这一段注释中，了解到默认仓库的存放目录是：${user.home}/.m2/repository，也就是系统的家目录中，家目录是存放在C盘（系统盘）当中的。

C盘 – 用户 – 用户名 – .m2 – repository

…

当我们累计使用的 jar包越来越多，Maven仓库的体积也将越来越大，内存过大会拖慢所在C盘的运行速度，影响系统性能。为了避免这样的结果，我们才需要设置本地仓库的路径，将Maven本地仓库放置在别的盘当中。

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⚪怎么做

我们需要在配置文件中加入一行代码，来配置本地仓库：

  <localRepository>d:\maven-repository</localRepository>

localRepository标签中的内容就填写我们自己配置的本地仓库路径，我们只需要手动创建一个空文件夹，将此文件夹的路径复制到标签中即可；
当然不创建也没问题，在标签中设置好路径后，当我们使用本地仓库时，Maven会帮我们创建的~

需要注意的是：本地仓库的目录也要求不包含中文、空格。

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三、配置阿里云镜像仓库

⚪为什么

Maven在下载jar包时，默认会访问境外的中央仓库去进行下载，但是访问国外网站的速度较慢。为了提高访问速度从而提升效率，我们需要将Maven下载jar包时访问的仓库设置为国内阿里云提供的镜像仓库。

• 默认的中央仓库 - 访问国外网站 - 速度慢
• 阿里云镜像仓库 - 访问国内网站 - 速度快

⚪怎么做

依旧是打开Maven目录下，conf文件夹中的settings.xml文件，对settings.xml文件中<mirrors></mirrors>标签内的内容进行修改:

• 默认情况下的mirrors标签内容：

  <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>
      <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>

——————————

• 设置完阿里云镜像仓库后的mirrors标签内容：

改动：

1. 将原本给定的例子注释掉
2. 加入我们配置的镜像仓库内容（可直接复制）

  <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>
      <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>
     -->
	<mirror>
		<id>nexus-aliyun</id>
		<mirrorOf>central</mirrorOf>
		<name>Nexus aliyun</name>
		<url>http://maven.aliyun.com/nexus/content/groups/public</url>
	</mirror>

  </mirrors>

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四、配置Maven的JDK版本

⚪为什么

Maven工程默认使用JDK 1.5的版本，而实际上常用的是 JDK 1.8 及以上版本。

⚪怎样做

打开Maven目录下，conf文件夹中的settings.xml文件，对settings.xml文件中<profiles></profiles>标签内的内容进行修改:

• 默认情况下的profiles标签内容：

全都是注释

  <profiles>
    <!-- profile
     | Specifies a set of introductions to the build process, to be activated using one or more of the
     | mechanisms described above. For inheritance purposes, and to activate profiles via <activatedProfiles/>
     | or the command line, profiles have to have an ID that is unique.
     |
     | An encouraged best practice for profile identification is to use a consistent naming convention
     | for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 'user-brett', etc.
     | This will make it more intuitive to understand what the set of introduced profiles is attempting
     | to accomplish, particularly when you only have a list of profile id's for debug.
     |
     | This profile example uses the JDK version to trigger activation, and provides a JDK-specific repo.
    <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>
    -->

    <!--
     | Here is another profile, activated by the system property 'target-env' with a value of 'dev',
     | which provides a specific path to the Tomcat instance. To use this, your plugin configuration
     | might hypothetically look like:
     |
     | ...
     | <plugin>
     |   <groupId>org.myco.myplugins</groupId>
     |   <artifactId>myplugin</artifactId>
     |
     |   <configuration>
     |     <tomcatLocation>${tomcatPath}</tomcatLocation>
     |   </configuration>
     | </plugin>
     | ...
     |
     | NOTE: If you just wanted to inject this configuration whenever someone set 'target-env' to
     |       anything, you could just leave off the <value/> inside the activation-property.
     |
    <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>

————————————

• 配置后的profiles标签内容：

改动：

1. 添加了设置JDK版本的相关配置（配置在下述代码尾部，可直接复制）

  <profiles>
    <!-- profile
     | Specifies a set of introductions to the build process, to be activated using one or more of the
     | mechanisms described above. For inheritance purposes, and to activate profiles via <activatedProfiles/>
     | or the command line, profiles have to have an ID that is unique.
     |
     | An encouraged best practice for profile identification is to use a consistent naming convention
     | for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 'user-brett', etc.
     | This will make it more intuitive to understand what the set of introduced profiles is attempting
     | to accomplish, particularly when you only have a list of profile id's for debug.
     |
     | This profile example uses the JDK version to trigger activation, and provides a JDK-specific repo.
    <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>
    -->

    <!--
     | Here is another profile, activated by the system property 'target-env' with a value of 'dev',
     | which provides a specific path to the Tomcat instance. To use this, your plugin configuration
     | might hypothetically look like:
     |
     | ...
     | <plugin>
     |   <groupId>org.myco.myplugins</groupId>
     |   <artifactId>myplugin</artifactId>
     |
     |   <configuration>
     |     <tomcatLocation>${tomcatPath}</tomcatLocation>
     |   </configuration>
     | </plugin>
     | ...
     |
     | NOTE: If you just wanted to inject this configuration whenever someone set 'target-env' to
     |       anything, you could just leave off the <value/> inside the activation-property.
     |
    <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>
    -->

	<profile>
	  <id>jdk-1.8</id>
	  <activation>
		<activeByDefault>true</activeByDefault>
		<jdk>1.8</jdk>
	  </activation>
	  <properties>
		<maven.compiler.source>1.8</maven.compiler.source>
		<maven.compiler.target>1.8</maven.compiler.target>
		<maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
	  </properties>
	</profile>

  </profiles>

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五、配置环境变量

——————————————

⚪配置Java环境变量

Maven 是一个用 Java 语言开发的程序，它必须基于 JDK 来运行,学习过Java的同学应该都配置过Java环境变量，可以直接跳过这一步。

如果还未下载JDK，配置Java环境变量，可以参考这篇文章：JDK安装+配置环境变量

检查：

Win+R 输入 cmd 进入命令指示符界面，使用以下指令检查：

java -version

echo %JAVA_HOME%

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⚪配置Maven环境变量

• 打开之间下载解压好的Maven文件目录，复制路径进行备用：

👇

• 打开计算机高级系统设置，选择环境变量，新建MAVEN_HOME:

AND

👇

• 系统变量选择Path进行编辑，在Path环境当中增加一个MAVEN_HOME的bin目录：

%MAVEN_HOME%\bin

👇
检查：

Win+R 输入 cmd 进入命令指示符界面，使用以下指令检查：

mvn -v

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如果出现以下提示：

说明没有读取到环境变量

👇

• 在用户变量的Path环境变量也添加MAVEN_HOME，之后再检查一次:

%MAVEN_HOME%\bin

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到了这里，我们就成功从0完成了Maven的下载，安装以及配置啦~
恭喜！