Java EE (Java Enterprise Edition) General Discussion

I use Tomcat for my JSP custom tag.
I have exer.jsp in the /jsp directory.
On /jsp/tags/ directory I have hello.java and helloparam.java that are both the custom tags.
I have chat-taglib.tld in /jsp/tags/ directory also
Inside the chat-taglib.tld I have defined the name of the
tags, where the class is, and the parameter if necessary.
I have my web.xml point to the location of the taglib.

However, when I run my exer.jsp, it gives me error said can not load the jsp.tags.hello class and thus can not
instantiate it.

I recompile and restart Tomcat over and over again...
But it gives me error message.
Tomcat is weird...please help me.

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Here is the error message:
Error: 500
Location: /chat/jsp/exer.jsp
Internal Servlet Error:

org.apache.jasper.compiler.CompileException: C:\jakarta-tomcat-3.2.1\jakarta-tomcat-3.2.1\webapps\chat\jsp\exer.jsp(10,0) Unable to load class jsp.tags.hello
at org.apache.jasper.compiler.TagBeginGenerator.init(TagBeginGenerator.java:129)
at org.apache.jasper.compiler.JspParseEventListener$GeneratorWrapper.init(JspParseEventListener.java:761)
at org.apache.jasper.compiler.JspParseEventListener.addGenerator(JspParseEventListener.java:138)
at org.apache.jasper.compiler.JspParseEventListener.handleTagBegin(JspParseEventListener.java:911)
at org.apache.jasper.compiler.DelegatingListener.handleTagBegin(DelegatingListener.java:194)
at org.apache.jasper.compiler.Parser$Tag.accept(Parser.java:813)
at org.apache.jasper.compiler.Parser.parse(Parser.java:1077)
at org.apache.jasper.compiler.Parser.parse(Parser.java:1042)
at org.apache.jasper.compiler.Parser.parse(Parser.java:1038)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:182)
at org.apache.jasper.servlet.JspServlet.doLoadJSP(JspServlet.java:462)
at org.apache.jasper.servlet.JasperLoader12.loadJSP(JasperLoader12.java:146)
at org.apache.jasper.servlet.JspServlet.loadJSP(JspServlet.java:433)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.loadIfNecessary(JspServlet.java:152)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:164)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:318)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:391)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404)
at org.apache.tomcat.core.Handler.service(Handler.java:286)
at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:797)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:210)
at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498)
at java.lang.Thread.run(Thread.java:484)

==========
Both hello.java and helloparam are compiled okay.
I check the .class files reside in jsp/tags/ dreictory.
I can not find anything wrong, please give me suggestion.
Thanks a lot,
Ted.