我把一本jsp教程光盘里的jsp例子拷到我的tomcat home/webappswebapps/jspDev目录下。该目录包括如下文件：
src\com\Bean\UserInfo.java
WEB-INF\classes\com\Bean\UserInfo.java
WEB-INF\Web.xml
index.jsp(该程序没有问题 内容如下：
<%@ page language="java" contentType="text/html; charset=gb2312"%>
<html>
<head>
<title>用户注册</title>
<link rel="stylesheet" type="text/css" href="css/style.css">
</head>
<body>
<center>
<form action="doreg.jsp" method="get">
<table border="1" style="margin-top:150" width="250">
<tr height="25" bgcolor="lightgrey">
<td align="center" colspan="2">用户注册</td>
</tr>
<tr>
<td align="right">用户名：</td>
<td align="center"><input type="text" name="name" size="29"></td>
</tr>
<tr>
<td align="right">职 务：</td>
<td align="center"><input type="text" name="job" size="29"></td>
</tr>
<tr>
<td align="center" colspan="2">
<input type="submit" value="注册">
<input type="reset" value="重置">
</td>
</tr>
</table>
</form>
<br>
</center>
</body>
</html>
）
处理上面表单中输入的信息的jsp：
doreg.jsp 内容如下：
<%@ page language="java" contentType="text/html; charset=gb2312"%>
<jsp:useBean id="us" class="com.Bean.UserInfo" scope="request"/>
<jsp:setProperty name="us" property="*"/>
<%
String name=us.getName();
String job=us.getJob();
if(name.equals("")||job.equals("")){
%>
<jsp:forward page="/false.jsp"/>
<% }else{ %>
<jsp:forward page="/success.jsp"/>
<% } %>
还有
success.jsp
false.jsp
我每次把表单的信息输入后，点注册按钮后，就出现下面的tomcat错误：
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: /doreg.jsp(2,0) The value for the useBean class attribute com.Bean.UserInfo is invalid.
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:148)
org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1200)
org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1155)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2338)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2388)
org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2394)
org.apache.jasper.compiler.Node$Root.accept(Node.java:489)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2338)
org.apache.jasper.compiler.Generator.generate(Generator.java:3374)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:210)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:306)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:286)