无法删除
C：\ EclipseProjects \ myGoogleAppEngine \ target \ myGoogleAppEngine-0.0.1-SNAPSHOT \WEB-INF \lib \ spring-webmvc-3.1.0.RELEASE.jar

Failed to delete C:\EclipseProjects\myGoogleAppEngine\target\myGoogleAppEngine-0.0.1-SNAPSHOT\WEB-INF\lib\spring-webmvc-3.1.0.RELEASE.jar

由于路径 C：\ EclipseProjects 我猜你在该项目上运行了eclipse。如果应用程序运行，则无法清除输出，因为它可能正在使用中。

Because of the path C:\EclipseProjects i guess you have eclipse running on that project. If you application runs, you cannot clean the output, because it may be in use.

停止应用程序，可能会发生异常情况并重试。

Stop the application and maybe eclipse and try again.