tomcat7 与tomcat 6 对request.getRequestDispatcher支持不同么 求救指正解决办法

tomcat7 与tomcat 6 对request.getRequestDispatcher支持不同么 求救指正
该段段程序在tomcat6 下执行正常，在tomcat7下报错，请求高手指点迷津！谢谢

程序功能：登陆，取到一个list然后，写入到request中，然后跳转到新的页面在其上显示列表。

登陆验证部分没有问题 ，代码出现在这个servlet中，红色语句出现异常：

Java code

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.city.gameroll.bussiness.IGroupBusiness;
import com.city.gameroll.factory.BusinessFactory;
import com.city.gameroll.value.GroupValue;

public class LoginGetGameListAction extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        IGroupBusiness gb=BusinessFactory.getGroup();


        try {
            //取得gamelist
            Collection<GroupValue> waitGameList = new ArrayList<GroupValue>();
            waitGameList=gb.getWaitGameList();
            request.setAttribute("waitGameList", waitGameList);
//此处出线异常
            request.getRequestDispatcher("user/main.jsp").forward(request, response); 
        } catch (Exception e) {

            System.out.println("LoginGetGameListAction出错"+e.getMessage());
        }
        
        
    }

    
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        doGet(request,response);
    }


}

在tomcat7下运行时，在注释部分抛出异常：
LoginGetGameListAction出错The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
2011-2-15 17:05:05 org.apache.catalina.core.ApplicationDispatcher invoke
严重: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:53)
at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:409)
at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:116)
at org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:310)
at org.apache.jasper.compiler.TagLibraryInfoImpl.<init>(TagLibraryInfoImpl.java:152)
at org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:410)
at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:475)
at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1425)
at org.apache.jasper.compiler.Parser.parse(Parser.java:138)
at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:239)
at org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:197)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:365)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:345)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:332)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:594)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:342)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:306)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:672)