昨天遇到个问题我jboss4启动xfire接口程序报以下错误：
java.lang.NoClassDefFoundError: javax/servlet/http/HttpServletRequest
Caused by: java.lang.LinkageError: loader constraint violation: loader (instance of org/jboss/mx/loading/UnifiedClassLoader3) previously initiated loading for a different type with name "javax/servlet/http/HttpServletRequest"
这个问题用各种方法(包括换jar，换jdk，换jboss)调了半天也不知道为什么又好了能启动，今天开这个服务又遇到这个问题，求大神帮忙解答到底哪出了问题