大家帮忙看看什么问题,困绕我好几天了....JSP老是编译不成功

页面报的505错误....:org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: 13 in the jsp file: /bbs_index.jsp
Generated servlet error:
F:\tomcat\work\Catalina\localhost\BBS_Demo\org\apache\jsp\bbs_005findex_jsp.java:60: incompatible types
found   : java.lang.Object
required: java.util.List
list=request.getAttribute("list");
                                 ^
1 error控制台报的错误:2009-7-25 14:46:03 org.apache.jasper.compiler.Compiler generateClass
严重: Javac exception 
Compile failed; see the compiler error output for details.
at org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:944)
at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:764)
at org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:382)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:409)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312)
at servlet.Bbs_servlet.doPost(Bbs_servlet.java:50)
at servlet.Bbs_servlet.doGet(Bbs_servlet.java:33)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:534)
2009-7-25 14:46:03 org.apache.jasper.compiler.Compiler generateClass
严重: Env: Compile: javaFileName=/F:/tomcat/work/Catalina/localhost/BBS_Demo//org/apache/jsp\bbs_005findex_jsp.java
    classpath=/F:/tomcat/webapps/BBS_Demo/WEB-INF/classes/;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/Oracle-Driver.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/classes12.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/commons-pool-1.4.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/jstl.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/standard.jar;F:\tomcat\work\Catalina\localhost\BBS_Demo;/F:/tomcat/webapps/BBS_Demo/WEB-INF/classes/;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/Oracle-Driver.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/classes12.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/commons-pool-1.4.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/jstl.jar;/F:/tomcat/webapps/BBS_Demo/WEB-INF/lib/standard.jar;F:/tomcat/shared/classes/;F:/tomcat/common/classes/;F:/tomcat/common/endorsed/xercesImpl.jar;F:/tomcat/common/endorsed/xml-apis.jar;F:/tomcat/common/lib/ant-launcher.jar;F:/tomcat/common/lib/ant.jar;F:/tomcat/common/lib/commons-collections-3.1.jar;F:/tomcat/common/lib/commons-dbcp-1.2.1.jar;F:/tomcat/common/lib/commons-el.jar;F:/tomcat/common/lib/commons-pool-1.2.jar;F:/tomcat/common/lib/jasper-compiler.jar;F:/tomcat/common/lib/jasper-runtime.jar;F:/tomcat/common/lib/jsp-api.jar;F:/tomcat/common/lib/naming-common.jar;F:/tomcat/common/lib/naming-factory.jar;F:/tomcat/common/lib/naming-java.jar;F:/tomcat/common/lib/naming-resources.jar;F:/tomcat/common/lib/servlet-api.jar;/F:/tomcat/bin/bootstrap.jar;/D:/j2sdk1.4.2_12/lib/tools.jar;/D:/j2sdk1.4.2_12/jre/lib/ext/dnsns.jar;/D:/j2sdk1.4.2_12/jre/lib/ext/ldapsec.jar;/D:/j2sdk1.4.2_12/jre/lib/ext/localedata.jar;/D:/j2sdk1.4.2_12/jre/lib/ext/sunjce_provider.jar
    cp=F:\tomcat/bin/bootstrap.jar;D:\j2sdk1.4.2_12/lib/tools.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\classes
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\Oracle-Driver.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\classes12.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\commons-pool-1.4.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\jstl.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\standard.jar
    cp=F:\tomcat\work\Catalina\localhost\BBS_Demo
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\classes
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\Oracle-Driver.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\classes12.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\commons-pool-1.4.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\jstl.jar
    cp=F:\tomcat\webapps\BBS_Demo\WEB-INF\lib\standard.jar
    cp=F:\tomcat\shared\classes
    cp=F:\tomcat\common\classes
    cp=F:\tomcat\common\endorsed\xercesImpl.jar
    cp=F:\tomcat\common\endorsed\xml-apis.jar
    cp=F:\tomcat\common\lib\ant-launcher.jar
    cp=F:\tomcat\common\lib\ant.jar
    cp=F:\tomcat\common\lib\commons-collections-3.1.jar
    cp=F:\tomcat\common\lib\commons-dbcp-1.2.1.jar
    cp=F:\tomcat\common\lib\commons-el.jar
    cp=F:\tomcat\common\lib\commons-pool-1.2.jar
    cp=F:\tomcat\common\lib\jasper-compiler.jar
    cp=F:\tomcat\common\lib\jasper-runtime.jar
    cp=F:\tomcat\common\lib\jsp-api.jar
    cp=F:\tomcat\common\lib\naming-common.jar
    cp=F:\tomcat\common\lib\naming-factory.jar
    cp=F:\tomcat\common\lib\naming-java.jar
    cp=F:\tomcat\common\lib\naming-resources.jar
    cp=F:\tomcat\common\lib\servlet-api.jar
    cp=F:\tomcat\bin\bootstrap.jar
    cp=D:\j2sdk1.4.2_12\lib\tools.jar
    cp=D:\j2sdk1.4.2_12\jre\lib\ext\dnsns.jar
    cp=D:\j2sdk1.4.2_12\jre\lib\ext\ldapsec.jar
    cp=D:\j2sdk1.4.2_12\jre\lib\ext\localedata.jar
    cp=D:\j2sdk1.4.2_12\jre\lib\ext\sunjce_provider.jar
    work dir=F:\tomcat\work\Catalina\localhost\BBS_Demo
    extension dir=D:\j2sdk1.4.2_12\jre\lib\ext
    srcDir=F:\tomcat\work\Catalina\localhost\BBS_Demo
    include=org/apache/jsp/bbs_005findex_jsp.java2009-7-25 14:46:03 org.apache.jasper.compiler.Compiler generateClass
严重: Error compiling file: /F:/tomcat/work/Catalina/localhost/BBS_Demo//org/apache/jsp\bbs_005findex_jsp.java     [javac] Compiling 1 source fileF:\tomcat\work\Catalina\localhost\BBS_Demo\org\apache\jsp\bbs_005findex_jsp.java:60: incompatible types
found   : java.lang.Object
required: java.util.List
list=request.getAttribute("list");
                                 ^
1 errorservlet代码:public void doPost(HttpServletRequest request, HttpServletResponse response)
       throws ServletException, IOException 
{
response.setContentType("text/html;charset=gb2312");
request.setCharacterEncoding("gb2312");
// int id=Integer.parseInt(request.getParameter("id"));
// System.out.println(id);
String UserIP=request.getRemoteAddr();
System.out.println(UserIP);
Bbs_dao dao=new Bbs_dao();
List list=new ArrayList();
list=dao.OneList(UserIP);

System.out.println(list.size());
request.setAttribute("list",list);
request.getRequestDispatcher("bbs_index.jsp").forward(request, response);
}JSP代码:<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>页面1</title>
</head>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
List list=new ArrayList();
list=request.getAttribute("list");
%>
<body>
<table border="1" bordercolor="#0000">
<tr>
<td>id</td>
<td>ip</td>
<td>name</td>
<td>bkey</td>
<td>bvalue</td>
</tr>
<tr>
<td><%=list.size() %></td>
</tr>
</table>

</body>
</html>数据已经获得...但是传递到JSP页面上的时候就出这个编译不成功的错误.望指教...困绕了好多天了...急...