Idea 配合 Maven使用中有时遇到莫名奇妙的问题，又莫名奇妙的恢复正常。整理如下：
1、删除系统环境变量Maven_Home，只需在IDEA中指定Maven及settings.xml即可。
有时，系统环境变量中的Maven和IDEA中指定Maven地址不一致时，IDEA会加载系统环境变量中的Maven settings.xml配置。
2、Invalidate Caches 清理缓存。
有时错误的缓存，或者在控制台手动执行过mvn命令，却未指定正确的settings.xml 导致依赖下载失败。
3、mirrorOf 排除
<mirror>
<id>aliyunmaven</id>
<mirrorOf>!central,*</mirrorOf>
<name>阿里云公共仓库</name>
<url>https://maven.aliyun.com/repository/public</url>
</mirror>
</mirrors>
合理排除其他repository，避免*全走阿里云。
4、删除apache-maven/conf 下默认的settings.xml配置。
5、maven插件Lifecycle下clean成功，install失败，依赖不去本地仓库找，非要上远程仓库找，各种无解。。。
"D:\Program Files\Java\jdk1.8.0_171\bin\java.exe" -Dmaven.multiModuleProjectDirectory=D:\project\RuoYi\ruoyi-system -Dmaven.home=D:\Software\apache-maven\apache-maven\apache-maven-3.6.1 -Dclassworlds.conf=D:\Software\apache-maven\apache-maven\apache-maven-3.6.1\bin\m2.conf "-Dmaven.ext.class.path=D:\Program Files\JetBrains\ideaIU-2021.1.3.win\plugins\maven\lib\maven-event-listener.jar" "-javaagent:D:\Program Files\JetBrains\ideaIU-2021.1.3.win\lib\idea_rt.jar=63782:D:\Program Files\JetBrains\ideaIU-2021.1.3.win\bin" -Dfile.encoding=UTF-8 -classpath D:\Software\apache-maven\apache-maven\apache-maven-3.6.1\boot\plexus-classworlds-2.6.0.jar org.codehaus.classworlds.Launcher -Didea.version=2021.1.3 -s D:\maven_repository\ruoyi_settings.xml install [INFO] Scanning for projects... [INFO] [INFO] -----------------------< com.ruoyi:ruoyi-system >----------------------- [INFO] Building ruoyi-system 4.7.5 [INFO] --------------------------------[ jar ]--------------------------------- [INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 0.753 s [INFO] Finished at: 2022-12-27T13:40:45+08:00 [INFO] ------------------------------------------------------------------------ [ERROR] Failed to execute goal on project ruoyi-system: Could not resolve dependencies for project com.ruoyi:ruoyi-system:jar:4.7.5: Failed to collect dependencies at com.ruoyi:ruoyi-common:jar:4.7.5: Failed to read artifact descriptor for com.ruoyi:ruoyi-common:jar:4.7.5: Failure to find com.ruoyi:ruoyi:pom:4.7.5 in https://maven.aliyun.com/repository/public was cached in the local repository, resolution will not be reattempted until the update interval of public has elapsed or updates are forced -> [Help 1] [ERROR] [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch. [ERROR] Re-run Maven using the -X switch to enable full debug logging. [ERROR] [ERROR] For more information about the errors and possible solutions, please read the following articles: [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException Process finished with exit code 1
在 idea terminal 项目路径下执行
"D:\Program Files\Java\jdk1.8.0_171\bin\java.exe" -Dmaven.multiModuleProjectDirectory=D:\project\RuoYi\ruoyi-system -Dmaven.home=D:\Software\apache-maven\apache-maven\apache-maven-3.6.1 -Dclassworlds.conf=D:\Software\apache-maven\apache-maven\apache-maven-3.6.1\bin\m2.conf "-Dmaven.ext.class.path=D:\Program Files\JetBrains\ideaIU-2021.1.3.win\plugins\maven\lib\maven-event-listener.jar" "-javaagent:D:\Program Files\JetBrains\ideaIU-2021.1.3.win\lib\idea_rt.jar=63782:D:\Program Files\JetBrains\ideaIU-2021.1.3.win\bin" -Dfile.encoding=UTF-8 -classpath D:\Software\apache-maven\apache-maven\apache-maven-3.6.1\boot\plexus-classworlds-2.6.0.jar org.codehaus.classworlds.Launcher -Didea.version=2021.1.3 -s D:\maven_repository\ruoyi_settings.xml install -e
其实就是手动执行第一行，后面加参数 -e 可打印错误信息，没想到这就成功了。。看来maven插件这东西不靠谱多半有问题，还是手动执行实在。
