javabean 使用老是显示500 错误 说classnotfound

我用得是MyEclipse 7.0版本，tomcat 环境变量配置好，可以正常的显示大猫，也能在浏览器中浏览自己的jsp，就是加上javabean后会出现500错误。调试了一天了还是不行。代码如下：
类代码：package webb.test;public class person {
private String name;
private String sex;
private String telephone;
public String getSex() {
return sex;
} public void setSex(String sex) {
this.sex = sex;
}
public String getTelephone() {
return telephone;
} public void setTelephone(String telephone) {
this.telephone = telephone;
}
public String getName() {
return name;
} public void setName(String name) {
this.name = name;
}
public person()
{

}
}
jsp代码：
<%@ page language="java"  pageEncoding="ISO-8859-1"%>
<%@ page import="java.util.*,webb.test.person"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">    
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
  </head>
  
  <body>
    This is my JSP page. <br> 
    
    <jsp:useBean id="person1" class="webb.test.person" />
    <jsp:setProperty name="person1" property="name" value="qiya" />
    
      </body>
</html>
提示错误如下；
严重: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: /WebRoot/index.jsp(27,4) The value for the useBean class attribute webb.test.person is invalid.
at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)
at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:148)
at org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1203)
at org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1160)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2343)
at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2393)
at org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2399)
at org.apache.jasper.compiler.Node$Root.accept(Node.java:489)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2343)
at org.apache.jasper.compiler.Generator.generate(Generator.java:3365)
at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:199)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:315)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:295)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:282)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)