前台jsp页面
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'provincecityarea.jsp' starting page</title>
</head>
<body>
<select id="provinceID" style="width:150px">
<option>选择省份</option>
<option>河南</option>
<option>上海</option>
<option>杭州</option>
</select>
<select id="cityID" style="width:150px">
<option>选择城市</option>
</select>
<select id="areaID" style="width:150px">
<option>选择区域</option>
</select>
</body>
<!--
省份>城市
-->
<script type="text/javascript">
document.getElementById("provinceID").onchange = function() {
//清空城市下拉框
var cityEle = document.getElementById("cityID");
cityEle.options.length = 1;
//清空区域下拉框
var areaEle = document.getElementById("areaID");
areaEle.options.length = 1;
//定位到当前所选的值
var pro = this[this.selectedindex].innerHTML;
//如果选择了城市，开始触发ajax
if ("选择省份" != pro) {
var ajax = createAjax(); //创建ajax对象
function createAjax() {
var a = null;
try {
a = new ActiveXObject("microsoft.xmlhttp");
} catch (e) {
a = new XMLHttpRequest();
}
return a;
}
//设置参数
var method = "POST";
var url = "${pageContext.request.contextpath}/findCityByProvinceRequest?time="
+ new Date().getTime();
//准备请求
ajax.open(method,url);
//设置请求头
ajax.setRequestHeader("content-type","application/x-www-form-urlencoded")
var content = "bean.province=" + pro;
//向服务器发送
ajax.send(content);
//监听状态
ajax.onreadystatechange = function() {
if (ajax.readyState == 4) {
if (ajax.status == 200) {
//返回JAVA格式的JSON文本
var jsonJAVA = ajax.responseText;
//p所代表的是java格式的json文本，是不能直接被js执行的
//解决方案：将java格式的json文本，转成js格式的json文本
//如何做：用js提供的一个函数搞定
var jsonjs = eval("(" + jsonJAVA + ")");
//取城市数组
var array = jsonjs.cityList;
var size = array.length;
//遍历
for ( var i = 0; i < size; i++) {
var city = array[i];
//创建一个option节点，内容为城市数组的值
var option = document.createElement("option");
option.innerHTML = city;
//把option节点添加到select节点里面，即城市节点里面添加城市名
cityEle.appendChild(option);
}
}
}
}
}
}
</script>
<!-- 城市->区域 -->
<script type="text/javascript">
document.getElementById("cityID").onchange = function() {
var areaElement = document.getElementById("areaID");
areaElement.options.length = 1;
var city = this[this.selectedindex].innerHTML;
if ("选择城市" != city) {
//NO1)
var ajax = createAjax();
function createAjax() {
var a = null;
try {
a = new ActiveXObject("microsoft.xmlhttp");
} catch (e) {
a = new XMLHttpRequest();
}
return a;
}
//NO2)
var method = "POST";
var url = "${pageContext.request.contextpath}/findAreaByCityRequest?time="
+ new Date().getTime();
ajax.open(method,url);
//NO3)
ajax.setRequestHeader("content-type","application/x-www-form-urlencoded")
//NO4)
var content = "bean.city=" + city;
ajax.send(content);
//------------------------------------------等待
//NO5)
ajax.onreadystatechange = function() {
if (ajax.readyState == 4) {
if (ajax.status == 200) {
//NO6)
var jsonJAVA = ajax.responseText;
var jsonjs = eval("(" + jsonJAVA + ")");
var array = jsonjs.areaList;
var size = array.length;
for ( var i = 0; i < size; i++) {
var area = array[i];
var option = document.createElement("option");
option.innerHTML = area;
areaElement.appendChild(option);
}
}
}
}
}
}
</script>
</html>
城市和省份封装JavaBean
public class Bean {
private String province;// 省份
private String city;// 城市
public Bean() {
}
public String getProvince() {
return province;
}
public void setProvince(String province) {
this.province = province;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
}
struts的action处理
public class ProvinceCityAreaAction extends ActionSupport {
//封装对象属性，使用模型驱动的话需实现模型驱动接口，新建对象并私有，重写getModel()对象
private Bean bean;
public Bean getBean() {
return bean;
}
public void setBean(Bean bean) {
this.bean = bean;
}
/**
* 根据省份获取城市
*/
public String findCityByProvince() throws Exception {
cityList = new ArrayList<String>();
if ("上海".equals(bean.getProvince())) {
cityList.add("闵行");
cityList.add("浦东");
} else if ("河南".equals(bean.getProvince())) {
cityList.add("洛阳");
cityList.add("郑州");
cityList.add("焦作");
} else if ("杭州".equals(bean.getProvince())) {
cityList.add("余杭");
cityList.add("江干");
cityList.add("西湖");
cityList.add("萧山");
}
// 让struts2框架帮你将List/Set/Map<String>转成JSON文本
return SUCCESS;
}
/**
* 根据城市获取区域
*/
public String findAreaByCity() throws Exception {
areaList = new ArrayList<String>();
if ("洛阳".equals(bean.getCity())) {
areaList.add("AA");
areaList.add("BB");
} else if ("闵行".equals(bean.getCity())) {
areaList.add("CC");
areaList.add("DD");
;
} else if ("西湖".equals(bean.getCity())) {
areaList.add("EE");
areaList.add("FF");
} else if ("郑州".equals(bean.getCity())) {
areaList.add("GG");
areaList.add("HH");
}
return SUCCESS;
}
private List<String> areaList;// 区域的集合
private List<String> cityList;// 城市的集合
public List<String> getCityList() {
return cityList;
}
public List<String> getAreaList() {
return areaList;
}
}
struts.xml配置
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<package name="myPackage" extends="json-default" namespace="/">
<!-- 全局结果类型 -->
<global-results>
<result name="success" type="json"/>
</global-results>
<action name="checkRequest" class="action.CheckcodeAction"
method="check">
</action>
<!-- 省份->城市 -->
<action
name="findCityByProvinceRequest"
class="provincecityarea.ProvinceCityAreaAction"
method="findCityByProvince">
</action>
<!-- 城市->区域 -->
<action
name="findAreaByCityRequest"
class="provincecityarea.ProvinceCityAreaAction"
method="findAreaByCity">
</action>
</package>
</struts>