Failure to transfer com.thoughtworks.xstream:xstream:jar:1.3.1 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.
解决办法：
a. 删除m2\repository 所有 .lastUpdated为扩展名的文件
b. 然后在工程上点击右键，选择Maven4MyEclipse，然后选择Update Project Configuration，等待结果
c. 如果还是有错误，请多重复几次
