出现类似：
Could not calculate build plan: Failure to transfer org.apache.maven.plugins:maven-surefire-plugin:pom:2.7.1 from http://repo1.maven.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced. Original error: Could not transfer artifact org.apache.maven.plugins:maven-surefire-plugin:pom:2.7.1 from/to central (http://repo1.maven.org/maven2): Access denied to http://repo1.maven.org/maven2/org/apache/maven/plugins/maven-surefire-plugin/2.7.1/maven-surefire-plugin-2.7.1.pom. Error code 407, Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy service is denied. )
的问题时，在.m文件夹下找到加黑的文件处，把lastupdate文件删除，然后随便修改一下pom.xml（如加个空格）,保存后clear一下项目即可。会重新下载这些确实的文件