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.
解決辦法：
a. 刪除m2\repository 所有 .lastUpdated為擴展名的文件
b. 然后在工程上點擊右鍵，選擇Maven4MyEclipse，然后選擇Update Project Configuration，等待結果
c. 如果還是有錯誤，請多重復幾次