1.今天使用命令mvn compile編譯maven項目時提示錯誤信息，部分錯誤信息如下：
Failure to transfer wsdl4j:wsdl4j:jar:1.6.3 from http://xx.xx.xx.xx:8081/nexus/content/groups/public was cached in the local repository, resolution will not be reattempted until the update interval of public has elapsed or updates are forced. Original error: Could not transfer artifact wsdl4j:wsdl4j:jar:1.6.3 from/to public (http://xx.xx.xx.xx:8081/nexus/content/groups/public): The operation was cancelled.
發現wsdl4j-1.6.3.jar下載到本地時失敗，從提示可知是本地倉庫的緩存（cached）造成。我們找到maven的倉庫目錄,找到該jar的下載目錄。找到.lastUpdated文件，刪除它。然后eclipse-->maven-->updateMaven,重新下載jar后。如果下載成功，那么這個錯誤就會消失。
2.MVN 構建項目時的一個問題--Could not resolve de pendencies for project
解決maven cannot change version of project facet dynamic web module to 3.0