[网络协议]maven项目下载pom中的依赖时出现xxx.pom 501 HTTPS Required

maven项目下载pom中的依赖时出现xxx.pom 501 HTTPS Required，例如：

Could not transfer artifact org.springframework.boot:spring-boot-starter-parent:pom:2.3.4.RELEASE from/to repo1 (http://repo1.maven.org/maven2/): Transfer failed for http://repo1.maven.org/maven2/org/springframework/boot/spring-boot-starter-parent/2.3.4.RELEASE/spring-boot-starter-parent-2.3.4.RELEASE.pom 501 HTTPS Required

原因是官方把中央仓库的地址已经换成了https协议，将pom.xml中的中央仓库配置修改为https即可，例：

  <mirrors>
  <!-- 阿里云中央仓库镜像 -->
	<!--<mirror>
      <id>nexus-aliyun</id>
      <mirrorOf>*</mirrorOf>
      <name>Nexus aliyun</name>
      <url>https://maven.aliyun.com/nexus/content/groups/public</url>
    </mirror> -->
	
    <!-- 中央仓库 -->
	<mirror>
		<id>repo1</id>
		<mirrorOf>central</mirrorOf>
		<name>Human Readable Name for this Mirror.</name>
		<url>https://repo1.maven.org/maven2/</url>
	</mirror>

  </mirrors>