全局变量的M2_HOME环境变量。参见设置参考:

The settings element in the settings.xml file contains elements used to define values which configure Maven execution in various ways, like the pom.xml, but should not be bundled to any specific project, or distributed to an audience. These include values such as the local repository location, alternate remote repository servers, and authentication information. There are two locations where a settings.xml file may live: The Maven install: $M2_HOME/conf/settings.xml A user's install: ${user.home}/.m2/settings.xml

使用-X选项启动maven(调试)并检查输出的开头。应该是这样的:

...
[INFO] Error stacktraces are turned on.
[DEBUG] Reading global settings from c:\....\apache-maven-3.0.3\conf\settings.xml
[DEBUG] Reading user settings from c:\....\.m2\settings.xml
[DEBUG] Using local repository at C:\....\repository
...

(原来的目录名称被我删除了)

您可以使用maven帮助插件来告诉您用户和全局设置文件的内容。

mvn help:effective-settings

将要求maven吐出组合的全局和用户设置。

确定Maven是否正在使用所需的settings.xml的快速且肮脏的方法将使其xml无效，并运行一些需要settings.xml的安全Maven命令。

如果它读取了settings.xml，那么Maven会报告一个错误:“读取settings.xml时出错…”

全局变量的M2_HOME环境变量。参见设置参考:

The settings element in the settings.xml file contains elements used to define values which configure Maven execution in various ways, like the pom.xml, but should not be bundled to any specific project, or distributed to an audience. These include values such as the local repository location, alternate remote repository servers, and authentication information. There are two locations where a settings.xml file may live: The Maven install: $M2_HOME/conf/settings.xml A user's install: ${user.home}/.m2/settings.xml

您对cletus(正确)回答的评论暗示涉及多个Maven设置文件。

Maven总是使用一个或两个设置文件。(${M2_HOME}/conf/settings.xml)中定义的全局设置始终是必需的。用户设置文件(定义在${user.home}/.m2/settings.xml中)是可选的。在用户设置中定义的任何设置优先于相应的全局设置。

你可以从命令行覆盖全局和用户设置的位置，下面的例子将全局设置设置为c:\global\settings.xml，用户设置为c:\user\settings.xml:

mvn install --settings c:\user\settings.xml 
     --global-settings c:\global\settings.xml

目前还没有属性或方法来确定Maven使用了哪些用户和全局设置文件。要访问这些值，您必须修改MavenCli和/或DefaultMavenSettingsBuilder以将文件位置注入解析的Settings对象。