JavaBean的'为useBean的类属性classes.UserData值无效“

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问题描述

我有两个JSP和未工作的一个JavaBean。我使用Tomcat 6.0。第一个JSP是GetName.jsp，位于C：\\ Tomcat的\\的webapps \\ APP1 \\ GetName.jsp：

I have two JSPs and a JavaBean that aren't working. I'm using Tomcat 6.0. The first JSP is GetName.jsp, located at C:\Tomcat\webapps\app1\GetName.jsp:

<HTML>
<BODY>
<FORM METHOD=POST ACTION="NextPage.jsp">
What's your name? <INPUT TYPE=TEXT NAME=username SIZE=20><BR>
What's your e-mail address? <INPUT TYPE=TEXT NAME=email SIZE=20><BR>
What's your age? <INPUT TYPE=TEXT NAME=age SIZE=4>
<P><INPUT TYPE=SUBMIT>
</FORM>
</BODY>
</HTML>

第二个JSP是NextPage.jsp上，位于C：\\ Tomcat的\\的webapps \\ APP1 \\ NextPage.jsp上：

The second JSP is NextPage.jsp, located at C:\Tomcat\webapps\app1\NextPage.jsp:

<jsp:useBean id="user" class="classes.UserData" scope="session"/>
<HTML>
<BODY>
You entered<BR>
Name: <jsp:getProperty name="user" property="username" /><BR>
Email: <jsp:getProperty name="user" property="email" /><BR>
Age: <jsp:getProperty name="user" property="age" /><BR>
</BODY>
</HTML>

我的JavaBean，的UserData，编译correcty，类文件位于C：\\ Tomcat的\\的webapps \\ APP1 \\ WEB-INF \\类：

My JavaBean, UserData, compiles correcty, and the class file is located at C:\Tomcat\webapps\app1\WEB-INF\classes:

package classes;

import java.io.Serializable;

public class UserData implements Serializable {
    String username;
    String email;
    int age;

    public UserData() {
    }

    public void setUsername( String value )
    {
        username = value;
    }

    public void setEmail( String value )
    {
        email = value;
    }

    public void setAge( int value )
    {
        age = value;
    }

    public String getUsername() { return username; }

    public String getEmail() { return email; }

    public int getAge() { return age; }
}

我也有我的web.xml文件，位于C以下：\\ Tomcat的\\的webapps \\ APP1 \\ WEB-INF：

I also have the following in my web.xml file, located at C:\Tomcat\webapps\app1\WEB-INF:

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app
  PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
  "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">

<web-app>
</web-app>

我的谷歌搜索建议是与类路径。我的类路径是当前; C：\\ Tomcat的\\ LIB \\ servlet的api.jar文件

My Google searches have suggested something to do with the classpath. My classpath is currently .;C:\Tomcat\lib\servlet-api.jar.

当我在GetName.jsp输入信息，然后点击按钮，Tomcat的给了我以下的NextPage.jsp上：

When I enter information in GetName.jsp and click on the button, Tomcat gives me the following for NextPage.jsp:

org.apache.jasper.JasperException: /NextPage.jsp(1,1) The value for the useBean class attribute classes.UserData 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$GenerateVisitor.visit(Generator.java:1203)
    org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1160)
    org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2343)
    org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2393)
    org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2399)
    org.apache.jasper.compiler.Node$Root.accept(Node.java:489)
    org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2343)
    org.apache.jasper.compiler.Generator.generate(Generator.java:3365)
    org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:199)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:315)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:295)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:282)
    org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

我可以发誓，我做的一切权利，但显然我不是。可能有人请告诉我之前，我撕我的头发出了什么问题？先谢谢了。

I could swear I'm doing everything right, but apparently I'm not. Could someone please tell me what's wrong before I tear all my hair out? Thanks in advance.

useBean的

JavaBean的'为useBean的类属性classes.UserData值无效“

问题描述

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