版权声明： https://blog.csdn.net/czjlghndcy/article/details/83351519
在执行maven的mvn clean命令的时候发现不成功，百度一番很多情况，要么的JDK配置成了JRE，要么就是Tomcat没有停止，发现这都不是我的原因。
解决办法：发现是target这个目录别被人软件占用了，然后关闭该软件，就发现可以执行成功啦~
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-clean-plugin:2.4.1:clean (default-clean) on project mall2: Failed to clean project: Failed to delete E:\
IDEAWork\mall2\target -> [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/MojoExecutionException
