都采用subversion 进行版本控制，可以根据URL通过浏览器直接查看，也可以用svn客户端checkout下来，仔细研究源码还是不错呀。
=================== Struts ================================
Apache 项目 svn 资源
svn co http://svn.apache.org/repos/asf/
Struts svn 资源
svn co http://svn.apache.org/repos/asf/struts/
=================== Hibernate ================================
Hibernate svn 资源
Source Control Repositories
Starting in March, 2006 Hibernate source is maintained in a Subversion repository hosted by the JBoss Labs project. For anonymous access, the root repository URL is http://anonsvn.jboss.org/repos/hibernate/. For developer access, the root repository URL is https://svn.jboss.org/repos/hibernate/.
Also, the repository layout is expected to change to better align with the subproject structure. Currently, the layout essentially follows that found in the older CVS modules, with trunk, branches, and tags all at the root level of the repository. Thus to checkout the latest source for the Hibernate3 module, type
svn co http://anonsvn.jboss.org/repos/hibernate/trunk/Hibernate3
To checkout Hibernate Annotations and Hibernate EntityManager, type
svn co http://anonsvn.jboss.org/repos/hibernate/trunk/HibernateExt
or (for branch 3.2)
svn co http://anonsvn.jboss.org/repos/hibernate/branches/Branch_3_2/HibernateExt
Then you'll find metadata which contains Hibernate Annotations, ejb which contains Hibernate EntityManager and ejb-api which contains the javax.persistence APIs of EJB3.
Note that some of the modules present in CVS were dropped after import into Subversion; namely Hibernate and Hibernate2 modules. If you need access to these source trees, they are still accessible from the SourceForge CVS repository. For anonymous access, use pserver:anonymous@cvs.sourceforge.net:/cvsroot/hibernate as the CVSROOT.
NHibernate uses Subversion hosted on Sourceforge. The repository URL is https://svn.sourceforge.net/svnroot/nhibernate. Using this URL directly will cause all branches and tags of the project to be checked out, transferring a large volume of data. To check out only the trunk (main development line), use https://svn.sourceforge.net/svnroot/nhibernate/trunk as the repository URL.
The repositories are also browsable online via ViewCVS and Fisheye.
=================== Spring ================================
Subversion Access
This project's SourceForge.net Subversion repository can be checked out through SVN with the following instruction set:
svn co http://springframework.svn.sourceforge.net/svnroot/springframework
===================== 一个spring demo ============================
1.svn cohttp://spring-kickstart.googlecode.com/svn/trunk/
2.svn checkout http://openfans2.googlecode.com/svn/trunk/
=====================其他svn资源============================================
===============jakarta commom-lang svn================================
svn co http://svn.apache.org/repos/asf/jakarta/commons/proper/lang
===============SpringSide使用新鲜的Subversion管理源码=========================
SpringSide以Spring Framework为核心，提供一个 注重实效(Pragmatic)的企业应用KickStart 与Full-Stack 的开源构件库。
将Java社区众多优秀轻量级开源项目整军为一个黏合的框架，以构件式的开发架构，配合Ant与Eclipse plugin的生成工具，作为大家开发Java企业应用的方便起点.
URL: http://svn.javascud.org/svn/springside/springside2/trunk
xwork svn代码
http://svn.opensymphony.com/svn/xwork/tags/xwork_2-0-4/src/java/
hibernate svn代码
http://anonsvn.jboss.org/repos/hibernate/core/
struts2 svn代码
http://svn.apache.org/repos/asf/struts/struts2/
tomcat svn代码
http://svn.apache.org/repos/asf/tomcat/
spring svn代码
http://mail.freesky.com.cn/exchweb/bin/redir.asp?URL=https://springframework.svn.sourceforge.net/svnroot/springframework/repos/repo/org/springframework/spring/