关于Maven找不到jar包的解决方案

[ERROR] Failed to execute goal org.apache.tomcat.maven:tomcat7-maven-plugin:2.1:redeploy (default-cli) on project coreservlets: Execution default-cli of goal org.apache.tomcat.maven:tomcat7-maven-plugin:2.1:redeploy failed: Plugin org.apache.tomcat.maven:tomcat7-maven-plugin:2.1 or one of its dependencies could not be resolved: Failure to find org.apache.tomcat.embed:tomcat-embed-core:jar:7.0.37 in http://localhost:8081/nexus/content/groups/public/was cached in the local repository, resolution will not be reattempted until the update interval of nexus has elapsed or updates are forced-> [Help 1]

出现此错误时：was cached in the local repository, resolution will not be reattempted until the update interval of nexus has elapsed or updates are forced

解决办法：去自己的.m2 文件夹下把 xxx.lastUpdated文件全部删掉，重新运行maven，ok！或者在用maven时加 -U参数，就可以忽略xxx.lastUpdated..