Do you know what problem for <jsp:getProperty name="stat"
property="Hello"/> ?
why property 'Hello'  not in the JavaBean ?

JSP as below
<!-- This page was generated on <%=(new java.util.Date())%>-->
<!-- Using a JSP Method Declaration -->

<%@ page buffer="none" %>
<jsp:useBean id="stat" class="com.moonbean.bean01">

<%
    stat.setHello("book JSP");
%>
</jsp:useBean>

Hello User <p>

<%
out.println("This is " + stat.getHello());
%>

<jsp:getProperty name="stat" property="Hello"/>

JavaBean as below.

package com.moonbean;
import java.util.*;

public class bean01 {
    private int years;
    private String hello;

    public void setHello (String x) {
        hello = x;
    }
    public String getHello () {
        return hello;
    }

    public static void main(String[] args) {
        System.out.println("Testing");
        bean01 x = new bean01();
        x.setHello("Test");
        System.out.println(x.getHello());
    }
}

Error as below
exception

org.apache.jasper.JasperException: Cannot find any information on
property 'Hello' in a bean of type 'com.moonbean.bean01'
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:375)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)