Jquery、 ajax和struts2+Hibernate查询数据库验证用户名是否存在，表单禁止提交等！
最近学习了ajax的异步调用和刷新技术，就实践了一把。也借鉴了别人的方法，再加入自己的思路，就有了下面的东东```有任何疑问，就留言吧````
首先是前台的jsp页面
关于jquery的post方法大家可以去看看这个，写的很详细：http://www.itivy.com/jquery/archive/2011/7/6/jquery-get-post-getjson-ajax.html
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="/struts-tags" prefix="s"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'register.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script type="text/javascript" src="jquery-1.9.1.js"></script>//引进Jquery库
<script type="text/javascript">
jQuery(function()
{
$("#username").blur(function()
{
var username= $.trim($("#username").val());
$.post("checkusername.action",{username:username},function(date,state)
{
if(date.result=="ok")
{
$("#span1").html("<font color=\"red\">用户名可以使用</font>");
document.getElementById("submit").removeAttribute("disabled");
}else
{
$("#span1").html("<font color=\"red\">用户名不可以使用</font>");
document.getElementById("submit").disabled = "true";
}
//alert(date.result);警告不好看，太吓人了
return false;},'json');
});
});
</script>
</head>
<body>
<form action="savePerson.action" method="post" >
username:<input type="text" name="username" size="20" id="username">
<span id="span1"></span>
<br>
password:<input type="password" name="password" size="20"><br>
age: <input type="text" name="age" size="20"><br>
<input type="submit" value="提交" id="submit" disabled="disabled">
</form>
</body>
</html>
因为是使用的是struts2框架所以struts2里面加上如下代码：因为数据是采用接送传输的所以要写成extends="json-default"
<package name="strutsjson" extends="json-default">
<action name="checkusername"
class="com.liumin.action.CheckUsername" method="CheckPerson">
<result type="json"></result>
</action>
</package>
action里面的代码如下
package com.liumin.action;
import java.util.List;
import com.liumin.model.Person;
import com.liumin.service.impl.CheckService;
import com.opensymphony.xwork2.ActionSupport;
public class CheckUsername extends ActionSupport
{
private String username;//前台传来的数据username
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
private String result;
public String getResult()
{
return result;
}
public void setResult(String result)
{
this.result = result;
}
public String CheckPerson() throws Exception
{
CheckService checkService = new CheckService();
String str="select * from person where username='"+username+"'" ;//组建sql语句
List<Person> list=(List<Person>)checkService.getUser(str);//取得数据
if(list.isEmpty())//安条件查询后，判断list是否为空？
{
this.result = "ok";
}else
{
this.result = "no";
}
return SUCCESS;
}
}
service和dao层的我写到了一块：
package com.liumin.service.impl;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.Transaction;
import com.liumin.model.Person;
import com.liumin.util.HibernateUtil;
public class CheckService
{
@SuppressWarnings("unchecked")
public List<Person> getUser(String str)
{
Session session = HibernateUtil.openSession();
Transaction tx = session.beginTransaction();
List<Person> list = null;
try
{
list = session.createSQLQuery(str).addEntity(Person.class).list();//查询数据
tx.commit();
}
catch (Exception e)
{
if (null != tx)
{
tx.rollback();
}
}
finally
{
HibernateUtil.close(session);
}
return list;
}
}
util里面的数据如下：
package com.liumin.util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil
{
private static SessionFactory sessionFactory;
static
{
try
{
sessionFactory = new Configuration().configure().buildSessionFactory();
}
catch (Exception ex)
{
ex.printStackTrace();
}
}
public static Session openSession()
{
Session session = sessionFactory.openSession();
return session;
}
public static void close(Session session)
{
if(null != session)
{
session.close();
}
}
}
Hibernate的cfg和hbm代码就不用贴出来了！
