Hibernate+DWR无刷新三级联动

DWR(Direct Web Remoting)是一个用于改善web页面与Java类交互的远程服务器端Ajax开源框架,可以帮助开发人员开发包含AJAX技术的网站。它可以允许在浏览器里的代码使用运行在WEB服务器上的JAVA函数,就像它就在浏览器里一样。

使用DWR首先加入DWR的jar包.我这里用的是2.0.5的.

看代码吧,首先是index.jsp

 

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<%

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>ajax三级联动</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="dwr/engine.js"></script>

<script type="text/javascript" src="dwr/util.js"></script>

<!-- 导入DWR 为Java 对象动态生成的JavaScript 文件-->

<script type="text/javascript" src="dwr/interface/mydwr.js"></script>

<script type="text/javascript" src="jquery-1.8.3.min.js"></script></head>

<script type="text/javascript">

	$(function(){

		mydwr.findProvince(function(pro){

			for(var i=0;i<pro.length;i++){

				$(".province").append("<option value="+pro[i].id+">"+pro[i].province+"</option>");

			}

		});

	});



</script> 

  <body>

    	省:<select name="province" class="province">

    		<option value="0">==请选择==</option>

   		   </select>

    	市:<select name="city" class="city">

    		<option>==请选择==</option>

    		</select>

    	区:<select name="town" class="town">

    		<option>==请选择==</option>

    		</select>

  </body>

  <script type="text/javascript">

  	$(".province").change(function(){

  		if($(".province").val()==0){

  			$(".city option").remove();

  			$(".city").append("<option value=0>==请选择==</option>");

			$(".town option").remove();

  			$(".town").append("<option value=0>==请选择==</option>");

  			return;

  		}

		mydwr.findCityById($(this).val(),function(city){

			$(".city option").remove();

			$(".city").append("<option value=0>==请选择==</option>");

			for(var i=0;i<city.length;i++){

				$(".city").append("<option value="+city[i].id+">"+city[i].city+"</option>");

			}

		});

	});

  	$(".city").change(function(){

  		if($(".city").val()==0){

  			$(".town option").remove();

  			$(".town").append("<option value=0>==请选择==</option>");

  			return;

  		} 

		mydwr.findTownById($(this).val(),function(town){

			$(".town option").remove();

			$(".town").append("<option value=0>==请选择==</option>");

			for(var i=0;i<town.length;i++){

				$(".town").append("<option value="+town[i].id+">"+town[i].town+"</option>");

			}

		});

	});

  </script>

</html>

 

 三个实体类

package cn.yo.entity;



import java.util.HashSet;

import java.util.Set;



public class Province implements java.io.Serializable {



	private Integer id;

	private String province;

	private Set cities = new HashSet(0);

	//省略了get,set方法

}

package cn.yo.entity;



import java.util.HashSet;

import java.util.Set;



public class City implements java.io.Serializable {



	private Integer id;

	private Province province;

	private String city;

	private Set towns = new HashSet(0);

	//省略了get,set方法

}

package cn.yo.entity;



public class Town implements java.io.Serializable {



	private Integer id;

	private City city;

	private String town;

	//省略了get,set方法

}

 dao类

package cn.yo.dao;



import java.util.List;

import org.hibernate.Session;

import cn.yo.entity.City;

import cn.yo.entity.Province;

import cn.yo.entity.Town;



public class ProvinceDao {

	//查询全部省

	public List<Province> findProvince(){

		Session session=HibernateSessionFactory.getSession();

		String hql="from Province";

		List<Province> province=session.createQuery(hql).list();

		if(province.size()>0){

			return province;

		}

		else{

			return null;

		}

	}

	//根据省的Id查询该省下的全部市

	public List<City> findCityById(int id){

		Session session=HibernateSessionFactory.getSession();

		String hql="from City c where c.province.id='"+id+"'";

		List<City> city=session.createQuery(hql).list();

		if(city.size()>0){

			return city;

		}else{

			return null;

		}

	}

	//根据市的Id查询该市下的全部镇

	public List<Town> findTownById(int id){

		Session session=HibernateSessionFactory.getSession();

		String hql="from Town t where t.city='"+id+"'";

		List<Town> town=session.createQuery(hql).list();

		if(town.size()>0){

			return town;

		}else{

			return null;

		}

	}

}

 web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5" 

	xmlns="http://java.sun.com/xml/ns/javaee" 

	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 

	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

  <welcome-file-list>

    <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

  <!-- DWR -->

  <servlet>

  	<servlet-name>dwr_invoker</servlet-name>

  	<servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>

  	<init-param>

  		<param-name>debug</param-name>

  		<param-value>true</param-value>

  	</init-param>

  	 <init-param>

             <param-name>crossDomainSessionSecurity</param-name>

             <param-value>false</param-value>

      </init-param>

      <init-param>

            <param-name>allowScriptTagRemoting</param-name>

            <param-value>true</param-value>

      </init-param>

  	

  </servlet>

  <servlet-mapping>

  	<servlet-name>dwr_invoker</servlet-name>

  	<url-pattern>/dwr/*</url-pattern>

  </servlet-mapping>

</web-app>

 dwr.xml:没有他就没有DWR哦,放在web.xml同一目录下

 1 <?xml version="1.0" encoding="UTF-8"?>

 2 <!DOCTYPE dwr PUBLIC

 3     "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN"

 4     "http://getahead.org/dwr/dwr20.dtd">

 5 

 6 <dwr>

 7 <allow>

 8      <create javascript="mydwr" creator="new">

 9          <param name="class" value="cn.yo.dao.ProvinceDao"/>

10      </create>

11      <convert match="cn.yo.entity.Province" converter="bean"/>

12      <convert match="cn.yo.entity.City" converter="bean"/>

13      <convert match="cn.yo.entity.Town" converter="bean"/>

14 </allow>

15 </dwr>

 

代码全部贴出,希望能给初学者一点帮助.写的不好,希望大家能提出建议.小弟感激不尽

原创作品,转载请注明出处.

 

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