还是关于JAVABEAN的问题
我用的是Eclipse   +   Tomcat.我建立的是Tomcat项目.在WEB-INF/src下建立了包ufrog之后建立Circle.java.实际文件夹WEB-INF/classes/ufrog下已经编译好了Circle.class.

<!--   Circle.java   -->
package   ufrog;

public   class   Circle   {
private   int   radii;

public   int   getRadii()   {
return   radii;
}
public   void   setRadii(int   r)   {
radii=r;
}
}

<!--   index.jsp   -->
<%@   page   contentType= "text/html;charset=GB2312 "   %>
<%@   page   import= "ufrog.Circle; "   %>

<jsp:useBean   id= "cir "   class= "Circle "   scope= "page "> </jsp:useBean>
<jsp:setProperty   property= "5 "   name= "radii "   />

<%
out.println( "半径是   "+   cir.getRadii());
%>

index.jsp是放在项目的根目录下

现在启动Tomcat之后出现问题
org.apache.jasper.JasperException:   /index.jsp(4,0)   The   value   for   the   useBean   class   attribute   Circle   is   invalid.
又或是
org.apache.jasper.JasperException:   Unable   to   load   class   for   JSP

我是刚开始接触jsp的开放.不知道Eclipse里面是不是也要进行甚么配置.望XD指教

------解决方案--------------------
<jsp:setProperty property= "5 " name= "radii " />

这行改为
<jsp:setProperty name= "cir " property= "radii " value= "5 " />