关于一些Javabean的问题！很严重！

bean类！！！
package com.mybean.data;

/**

• @autho Xran

*/
public class RegistBean {
public String UserName="",
Address="",
Phone="",
backNews=“请输入信息”;

public String getAddress() {
	return Address;
}

public void setAddress(String address) {
	this.Address = address;
}

public String getPhone() {
	return Phone;
}

public void setPhone(String phone) {
	this.Phone = phone;
}

public String getBackNews() {
	return backNews;
}

public void setBackNews(String backNews) {
	this.backNews = backNews;
}

public String getUserName() {
	return UserName;
}

public void setUserName(String userName) {
	this.UserName = userName;
}

}

servlet类！！
/**@author dell

• 注册servlet
  /
  package com.myservlet.control;
  import com.mybean.data.;
  import java.sql.;
  import java.io.;
  import javax.servlet.;
  import javax.servlet.http.;
  /**
• @autho Xran

*/
public class RegistServlet extends HttpServlet {
public void init(ServletConfig config)throws ServletException{
super.init(config);
try { Class.forName(“com.mysql.cj.jdbc.Driver”);
}
catch(Exception e) {}
}
public String RegistString(String s) {
try {byte bb[]=s.getBytes(“UTF-8”);
s=new String(bb);
}
catch(Exception ee) {}
return s;
}
public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{
String uri=“jdbc:mysql://localhost/bookstore?user=root&password=123&characterEncoding=UTF-8&serverTimezone=GMT”;
Connection con;
PreparedStatement sql;
RegistBean UserBean=new RegistBean(); //bean 对象
request.setAttribute(“UserBean”, UserBean);
String UserName=request.getParameter(“UserName”).trim();
String PassWord=request.getParameter(“PassWord”).trim();
String again_password=request.getParameter(“again_password”).trim();
String Phone=request.getParameter(“Phone”).trim();
String Address=request.getParameter(“Address”).trim();
if(UserNamenull)
UserName="";
if(PassWordnull)
PassWord="";
if(!PassWord.equals(again_password)) {
UserBean.setBackNews(“两次密码不同，注册失败，是不是傻！”);
RequestDispatcher dis=request.getRequestDispatcher(“regist.jsp”);
dis.forward(request, response);
return;
}
boolean isLD=true;
for(int i=0;i<UserName.length();i++) {
char c=UserName.charAt(i);
if(!((c<=‘z’&&c>=‘a’)||(c<=‘Z’&&c>=‘A’)||(c<=‘9’&&c>=‘0’)))
isLD=false;
}
boolean boo=UserName.length()>0&PassWord.length()>0&&isLD;
String backNews="";
try { con=DriverManager.getConnection(uri);
String insertCondition=“INSERT INTO user VALUES(?,?,?,?,?)”;
sql=con.prepareStatement(insertCondition);
if(boo) {
sql.setString(1, RegistString(UserName));
sql.setString(2, RegistString(PassWord));
sql.setString(3, RegistString(Phone));
sql.setString(4, RegistString(Address));
int m=sql.executeUpdate();
if(m!=0) {
backNews=“注册成功”;
UserBean.setBackNews(backNews);
UserBean.setUserName(UserName);
UserBean.setPhone(Phone);
UserBean.setAddress(Address);
}
}
else {
backNews=“信息填写不完整或名字中含非法字符”;
UserBean.setBackNews(backNews);
}
con.close();
}
catch(SQLException exp) {
backNews=“该会员名已存在，请更换！”;
UserBean.setBackNews(backNews);
}
RequestDispatcher dis=request.getRequestDispatcher(“regist.jsp”);
dis.forward(request, response);

}

}
jsp 页面！！！

<%@ page language=“java” contentType=“text/html; charset=UTF-8”
pageEncoding=“UTF-8”%>

<%@ include file ="/txt/head.txt"%>

用户名字由数字，字母，下划线构成，*注释的项必须填写！

*用户名称:	*用户密码:
*重复密码:		联系电话
邮寄地址

注册

会员名称
地址
电话

但是确报错！！ 这是为什么！！ 没有错误啊！！ 报错：file:/regist.jsp(28,5) jsp:getProperty for bean with name 'UserBean'. Name was not previously introduced as per JSP.5.3

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception
org.apache.jasper.JasperException: file:/regist.jsp(28,5) jsp:getProperty for bean with name ‘UserBean’. Name was not previously introduced as per JSP.5.3