From looking at your XSLT and expected results, it looks like that for each a element in your XML, you want to output infomation on the following c elements present, if any occur before the next a element present. For this, you could use an xsl:key t ...
http://blog.csdn.net/IBM_linghb1985/article/details/3866817 org.apache.jasper.JasperException: Unable to compile class for JSP: 把jdk安装目录下的lib/tools.jar拷贝到tomcat安装目录下的common/lib目录下,然后重启tomcat,试试