JSP表单填写验证---JSP+JavaBean

浏览数：27 / 时间：2015年06月08日

1、JavaBean

所谓JavaBean就是满足一定设计规则的Java类，需要满足的规则如下

（1）数据成员的属性为private

（2）每个数据成员拥有public属性的setXXX和getXXX方法

（3）有一个没有参数的public类型的构造函数

2、实例代码

package bean;

public class UserCheckBean{
	private String name;

	public UserCheckBean(){}
	public UserCheckBean(String name){
		this.name=name;
	}
	public void setName(String name){
		this.name=name;
	}
	public String getName(){
		return name;
	}
	public boolean validate(){
		return name.equals("cjc");
	}
}

登录界面

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style>
td{font-size:15pt;font-color:red;}
</style>
</head>
<body>
<form action="loginchk.jsp" method="post">
<table>
	<tr>
		<td>username</td>
		<td><input type="text" name="name"></td>
	</tr>
	<tr>
		<td>password</td>
		<td><input type="password" name="pw"></td>
	</tr>
	<tr>
		<td><input type="submit" value="Submit"></td>
		<td><input type="reset" value="Reset"></td>
	</tr>
</table>
</form>
</body>
</html>

验证JSP

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ page import="bean.UserCheckBean"%>
<jsp:useBean id="user" scope="session" class="bean.UserCheckBean"/>
<jsp:setProperty name="user" property="name" value="*"/>
<%
	String nm=request.getParameter("name");
	user.setName(nm);
	UserCheckBean uc=new UserCheckBean(nm);
	if(uc.validate())
	{
%>
	<jsp:forward page="welcome.jsp"/>
<%
	}
	else{
		out.println("The username does not exist!");
		out.println("<a href=\"login.html\">login again</a>");
	}
%>

欢迎界面

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>welcome</title>
</head>
<body>
<jsp:useBean id="user" scope="session" class="bean.UserCheckBean"/>
Welcome <jsp:getProperty name="user" property="name"/>!
</body>
</html>