Question

<jsp:useBean>问题

a.jsp源码：<%@page contentType="text/html" pageEncoding="gb2312"%>
<jsp:useBean id="h" scope="application" class="d"/>
<%--h.setHello("jsp:useBean");--%>
<%=h.getHello()%>
d.java源码：//package MyTest;
public class d
{String h="当然";
public void setHello(String n){h=n;}
public String getHello(){return h;}
}
结果报错：Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: /a.jsp(2,0) The value for the useBean class attribute d 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$GenerateVisitor.visit(Generator.java:1204)
org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1117)

是怎么回事？谁能随便给我一个能成功运行的<jsp:useBean>程序。只要能切实体会到<jsp:useBean>的作用。或者指出上面那个错误原因

Answer 1

你这个报错是说没有javabean是不可获得的
usebean标签没用过，bean是一个类，只要引入就行了
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"梁悄%>
<%@ page import="困搏MyBeans.TestJB"%>汪渣祥
<%
Vector vt=(Vector)request.getAttribute("result");
TestJB tj=new TestJB();
tj.setb1(v.get(0).toString());
%>
这样就调用了bean

Answer 2

class="d" 在默认包中 很可能报错的 。。给类d加包 就可以了

Answer 3

把你的类随便整个包放起，就不会有这个问题了