總共分為三組代碼 circle.jsp用于顯示 Circle.java 用于定義類 radiusInput用于輸入circle.jsp如下<%@ page language="java" import="circle.class" contentType="text/html;charset=GBK" pageEncoding="ISO-8859-1" session="True"%><jsp:useBean id="circleBean" scope="page" class="circle.Circle" type="java.lang.String" ></jsp:useBean></p><html><body><%int radius=Integer.parseInt(request.getParameter("radius"));circleBean.setRadius(radius);out.println("圓的半徑是:"+circleBean.getRadius());out.println("圓的周長是:"+circleBean.getLength());out.println("圓的面積是:"+circleBean.getArea());%></body></html>我用的是Tomcat6.0已經把circle.class類放在了C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\ROOT\WEB-INF\classes下 運行錯誤：org.apache.jasper.JasperException: /circle.jsp(2,0) The value for the useBean class attribute circle.Circle 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$GenerateVisitor.visit(Generator.java:1272)org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1178)org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361).........java程序如下：package circle;public class Circle{private int radius=1;public Circle(){}public int getRadius(){return radius;}public void setRadius(int rRadius){radius=rRadius;}public double circleLength(){return Math.PI*radius*2.0;}public double circleArea(){return Math.PI*radius*radius;}}radiusInput的jsp頁面可以正確運行 代碼我略去了。。。輸入半徑的代碼我也發了吧：<body><form id="form1" name="form1" method="post" action="circle.jsp">請輸入圓的半徑:<input name="radius" type="text" id="radius"/><input type="submit" name="submit" value="開始計算"/></form></body>
為什么會錯了呢 我都試了好久了？
GCT1015
2023-03-12 20:16:33
