错误：

ArtifactTransferException: Failure to transfer org.apache.hadoop:hadoop-hdfs:jar:2.6.0 from http://localhost:8081/nexus/content/groups/public/ 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.hadoop:hadoop-hdfs:jar:2.6.0 from/to central (http://localhost:8081/nexus/content/groups/public/): No response received after 60000

原因：:hadoop-hdfs:jar:2.6.0不能从远程仓库传输到本地中。

解决办法：到本地仓库中删除hadoop-hdfs文件夹，再右键工程-->Maven-->Update Project