spring的源代碼地址發生了更改，以前的地址是 https://src.springframework.org/svn/spring-framework/。但現在spring的代碼開始使用Git進行管理，新的源代碼地址爲：https://github.com/SpringSource/spring-framework。
因爲 GitHub 同樣支持svn的客戶端，因而仍然可以使用svn的命令進行代碼checkout。
附官方解釋：
The Spring Framework repository has moved to http://github.com/SpringSource/spring-framework. See the readme there for details on working with Git, building the framework, etc. Note that svn-based access is still available via GitHub's support for Subversion clients, e.g.: $ svn checkout https://github.com/SpringSource/spring-framework See https://github.com/blog/966-improved-subversion-client-support for more details.