The value for the useBean class attribute test.First is invalid

运行jsp时报错啊，求各位大侠相助啊。
The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: org.apache.jasper.JasperException: /2.jsp(7,2) The value for the useBean class attribute test.First is invalid.
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:565)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:354)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause org.apache.jasper.JasperException: /2.jsp(7,2) The value for the useBean class attribute test.First is invalid.
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:406)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:147)
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$Nodes.visit(Node.java:2336)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2386)
org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2392)
org.apache.jasper.compiler.Node$Root.accept(Node.java:489)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2336)
org.apache.jasper.compiler.Generator.generate(Generator.java:3397)
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)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:273)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:566)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:314)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

解决方案 »

  1.   

    jsp程序：<% @ page contentType="text/html;charSet=GBK"%>
    <html>
    <head>
    </head>
    <body>
      <% request.setCharacterEncoding("GBK");%>
      <jsp:useBean id="bean1" scope="session" class="test.First"/>
      <jsp:setProperty name="bean1" property="*"/>
      <form method="post">
         <input name="uid"/>
         <input type="submit" value="tijiao"/>
      </form>
      <jsp:getProperty name="bean1" property="uid"/>
    </body>
    </html>
    javaBean文件：
    package test;
    class  First
    {
    private String uid="20095409";
    public String getUid()
    {return uid;}
    public void setUid(String newid)
    {
    if (newid!=null)
    {
    uid=newid;
    }
    }
    }
    test包含在WEB-INF中的classes文件夹中，xml文件配置如下：
    <?xml version="1.0" encoding="ISO-8859-1"?><web-app >
       <servlet>
          <servlet-name>helloworldservlet</servlet-name>
          <servlet-class>helloworldservlet</servlet-class>
       </servlet>
       <servlet-mapping>
          <servlet-name>helloworldservlet</servlet-name>
          <url-pattern>/helloworldservlet</url-pattern>
       </servlet-mapping>
       <servlet>
          <servlet-name>load</servlet-name>
          <servlet-class>load</servlet-class>
       </servlet>
       <servlet-mapping>
          <servlet-name>load</servlet-name>
          <url-pattern>/load</url-pattern>
       </servlet-mapping>
       <servlet>
          <servlet-name>register</servlet-name>
          <servlet-class>register</servlet-class>
       </servlet>
       <servlet-mapping>
          <servlet-name>register</servlet-name>
          <url-pattern>/register</url-pattern>
       </servlet-mapping>
       <servlet>
          <servlet-name>ConDB</servlet-name>
          <servlet-class>test.ConDB</servlet-class>
       </servlet>
       <servlet-mapping>
          <servlet-name>ConDB</servlet-name>
          <url-pattern>/ConDB</url-pattern>
       </servlet-mapping><servlet>
          <servlet-name>First</servlet-name>
          <servlet-class>test.First</servlet-class>
       </servlet>
       <servlet-mapping>
          <servlet-name>First</servlet-name>
          <url-pattern>/First</url-pattern>
       </servlet-mapping>
    </web-app>
      

  2.   

    额，我自己来吧，javaBean没有申明为public