Hibernate+struts+JqueryAjax+jSON实现无刷新三级联动

浏览数：24 / 时间：2015年06月09日

看网上JqueryAjax三级联动的例子讲不是很全,代码也给的不是很全,给初学者带来一定的难度。小弟自己写了一个，可能有些地方不是很好，希望大家能够提出建议。

用的是Hibernate+struts2写的。http://blog.csdn.net/luckey_zh/article/details/22995389

以代码来说话吧。

首先是index1.jsp页面

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<%@ 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>Jquery-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="jquery-1.8.3.min.js"></script>
</head>
<script type="text/javascript">
$(function(){
$.ajax({
type:"post",
url:"province",
dataType:"json",
async:false,
success:function(data){
var pro=eval("("+data+")");
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">
$(".province").change(function(){
var province_id=$(".province").val();
//如果选择的是‘==请选择==’，不会执行去查找市，平且把已有的数据清空
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;
}
$.ajax({
type:"post",
//传一个省的id参数
url:"city?province_id="+province_id,
dataType:"json",
async:false,
success:function(city){
var city=eval("("+city+")");
for(var i=0;i<city.length;i++){
$(".city").append("<option value="+city[i].id+">"+city[i].city+"</option>");
}
}
});
});
//市下拉列表框发生改变时候的事件
$(".city").change(function(){
var city_id=$(".city").val();
if($(".city").val()==0){
$(".town option").remove();
$(".town").append("<option value=0>==请选择==</option>");
return;
}
$.ajax({
type:"post",
url:"town?city_id="+city_id,
dataType:"json",
async:false,
success:function(town){
var town=eval("("+town+")");
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：

1.Province实体类

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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

2.City实体类

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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

3.Town实体类

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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

本人比较懒，用的是Hibernate框架，HibernateSessionFactory这个类大家会用Hibernate应该都会知道，我就不贴出了。

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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;
}
}
}

接下来是action类

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package cn.yo.action;
import java.util.List;
import org.apache.struts2.ServletActionContext;
import net.sf.json.JSONArray;
import net.sf.json.JsonConfig;
import cn.yo.dao.ProvinceDao;
import cn.yo.entity.City;
import cn.yo.entity.Province;
import cn.yo.entity.Town;
import com.opensymphony.xwork2.ActionSupport;
public class ProvinceAction extends ActionSupport {
private String result;//返回到客户端的数据
//省略get,set方法
//获得省
public String findProvince()throws Exception{
ProvinceDao d=new ProvinceDao();
List<Province> p=d.findProvince();
System.out.println("------");
JsonConfig config=new JsonConfig();
//Hibernate中关联set需要过滤，不然会引起死循环。我在这吃了很大的亏，希望大家能重视
config.setExcludes(new String[]{"cities"});
//转化为JSON
JSONArray jArray = JSONArray.fromObject(p,config);
result=jArray.toString();
return SUCCESS;
}
//获得城市
public String findCity()throws Exception{
ProvinceDao d=new ProvinceDao();
int id=Integer.parseInt(ServletActionContext.getRequest().getParameter("province_id"));
List<City> c=d.findCityById(id);
JsonConfig config=new JsonConfig();
config.setExcludes(new String[]{"province","towns"});
JSONArray jArray=JSONArray.fromObject(c, config);
result=jArray.toString();
return SUCCESS;
}
//获得镇
public String findTown()throws Exception{
ProvinceDao d=new ProvinceDao();
int id=Integer.parseInt(ServletActionContext.getRequest().getParameter("city_id"));
List<Town> t=d.findTownById(id);
JsonConfig config=new JsonConfig();
config.setExcludes(new String[]{"city"});
JSONArray jArray=JSONArray.fromObject(t,config);
result=jArray.toString();
return SUCCESS;
}
}

在看struts2的配置

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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
<package name="myajax" namespace="/" extends="struts-default,json-default">
<action name="province" class="cn.yo.action.ProvinceAction" method="findProvince">
<result type="json">
<param name="root">result</param>
</result>
</action>
<action name="city" class="cn.yo.action.ProvinceAction" method="findCity">
<result type="json">
<param name="root">result</param>
</result>
</action>
<action name="town" class="cn.yo.action.ProvinceAction" method="findTown">
<result type="json">
<param name="root">result</param>
</result>
</action>
</package>
</struts>