[em19][em19][em19]

请教关于ejb方面的异常我在学习用jboss,tomcat 搭建ejb服务时，报以下异常，请问这代表什么意思呀！！

谢谢各位了！！

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HTTP Status 500 - 

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type Exception report

message 

description The server encountered an internal error () that prevented it from fulfilling this request.

exception 

org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
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.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)


root cause 

java.lang.ClassCastException
com.sun.corba.se.impl.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:229)
javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:137)
org.apache.jsp.common_jsp.jspInit(common_jsp.java:28)
org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:78)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:155)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:315)
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.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)


note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.


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Apache Tomcat/5.5.17

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出错页程序：

<%@ page import="mypack.*"%>
<%@ page import="java.util.Properties"%>
<%@ page errorPage="errorpage.jsp"%>
<%@ page import="javax.ejb.*"%>
<%@ page import="javax.naming.*"%>
<%@ page import="javax.rmi.PortableRemoteObject"%>
<%@ page import="java.rmi.RemoteException"%>

<%

    private BookDBEJB bookDB;
    
    public void jspInit(){
    
        bookDB = (BookDBEJB)getServletContext.getAttribute("bookDB");
        
        if(bookDB==null){
        
            try{
            
                InitialContext ic = new InitialContext();
                Object objRef=ic.lookup("java:comp/env/ejb/BookDBEJB");
                BookDBEJBHome home=(BookDBEJBHome)PortableRemoteObject.narrow(objRef,mypack.BookDBEJBHome.class);
                bookDB=home.create();
                getServletContext().setAttribute("bookDB",bookDB);
                
            }catch(RemoteException ex){
            
                System.out.println("Could not create database bean."+ex.getMessage());
            }catch(CreateException ex){
            
                System.out.println("Could not create database bean."+ex.getMessage());
            }catch(NamingException ex){
            
                System.out.println("Unable to look up home:"+"java:comp/env/ejb/BookDBEJB"+ex.getMessage());
            }
        }
    }

public void jspDestroy(){

    bookDB=null;

}

public String convert(String s){

    try{
    
        return new String(s.getBytes("ISO-8859-1"),"GB2312");
    
    }catch(Exception e){
    
        return null;
    
    }

}

%>

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谢谢[em18][em19][em19][em19][em19][em19]