移植到jboss发生的jsp错误

将应用从tomcat5.5移植到jboss环境下
个别jsp文件报错：
如下
The method setAttribute(String, Object, int) in the type JspContext is not applicable for the arguments (String, int)


org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:375)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1063)
org.apache.struts.action.RequestProcessor.internalModuleRelativeForward(RequestProcessor.java:1001)
org.apache.struts.action.RequestProcessor.processValidate(RequestProcessor.java:966)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:204)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

jboss内嵌了tomcat容器，似乎有些jar包还是跟正式的tomcat有些区别
上述问题是在pageContext.setAttribute("size",size);
这里报错的。
换成 pageContext.setAttribute("size",new Integer(size));通过。
但是在纯tomcat环境下，是正常的。