一.jquery入门
-
什么是jQuery
它是一个轻量级的javascript类库
注1:就一个类“jQuery”,简写“$” -
jQuery优点
2.1 总是面向集合
2.2 多行操作集于一行 -
hello jQuery
3.1 导入js库
<script type="text/javascript" src=""></script>
3.2 $(fn)做为程序入口
(
f
n
)
、
(fn)、
(fn)、(document).ready(fn)与window.onload的区别?
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<title>Insert title here</title>
<script type="text/javascript">
/* $(fn)、$(document).ready(fn)与window.onload的区别? 项目维护时用*/
//第一种
$(function() {
alert("hello jquery");
})
//第二种
$(document).ready(function() {
alert("hello jquery2");
})
//第三种
window.onload=function(){
alert("hello jquery3");
}
/* 结论:$(fn)、$(document).ready(fn)是等价的,哪个在前就执行哪个
jsp的demo树结构加载完毕即刻调用方法
window.onload最后执行
jsp的dom树加载完,css,js等静态资源加载完毕执行
*/
</script>
</head>
<body>
</body>
</html>
- jQuery三种工厂方法 (demo2.jsp)
4.1 jQuery(exp[,context])
exp:选择器
context:上下文,环境/容器,documemt
注1:选择器,css选择器
标签选择器
ID选择器
类选择器
包含选择器:E1 E2
组合选择器:E1,E2,E3
自定义选择器::exp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<title>Insert title here</title>
<script type="text/javascript">
$(function() {
//利用a标签获取jquery实例
/* $("a").click(function() {
alert("啦啦啦");
}); */
//利用id=a3获取jquery实例
/* $("#a3").click(function() {
alert("lalala");
}); */
//利用类获取jquery实例
/* $(".c1").click(function() {
alert("lalala");
}); */
//包含选择器
/* $("p a").click(function() {
alert("lalala");
}); */
//组合选择器
/* $("a,span").click(function() {
alert("lalala");
}); */
//讲解第二个参数的作用(在div标签内部寻找a标签,然后给找到的标签添加事件)
//如果第二个参数没有填,那么默认是documentr
$("a","div").click(function() {
alert("lalala");
});
})
</script>
</head>
<body>
<p>
<a id="a1" class="c1" href="#">点我1</a>
</p>
<p>
<a id="a2" class="c2" href="#">点我2</a>
</p>
<p>
<a id="a3" class="c3" href="#">点我3</a>
</p>
<div>
<a id="a4" class="c1" href="#">点我4</a>
</div>
<div>
<p>
<a id="a5" class="c1" href="#">点我5</a>
</p>
</div>
<span>点我</span>
</body>
</html>
4.2 jQuery(html) (demo3.jsp)
html:基于html的一个字符串
4.3 jQuery(element) (demo3.jsp)
element:js对象,表示一个html元素对象
js对象与jquery对象的相互转换
注1:$就是jQuery简写
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<title>Insert title here</title>
<script type="text/javascript">
$(function() {
$(":input[name='name1']").click(function() {
//在id=selId1的select的jquery实例上追加<option value='1'>湖南省</option>的html jquery实例
$("#selId1").append("<option value='1'>湖南省</option>");
});
$(":input[name='name2']").click(function() {
//将"<option value='1'>长沙</option>"的html jquery实例加到id=selId1的select标签jquery实例中
$("<option value='1'>长沙</option>").appendTo("#selId2");
//jquery怎么获取
/* var $h1=$("#h1");
alert($h1.val());
//jquery对象转js对象
var h1Node=$h1.get(0);//(看成集合)
var h1Node=$h1[0];//看成数组
alert(h1Node.value); */
var h2Node=document.getElementById("h2");
alert(h2Node.value);
//js 对象转jquery对象
$h2Node=$(h2Node);
alert($h2Node.val());
});
})
</script>
</head>
<body>
<select id="selId1">
<option value="-1">---请选择---</option>
</select>
<select id="selId2">
<option value="-1">---请选择---</option>
</select>
<input name="name1" value="add1" type="button">
<input name="name2" value="add2" type="button">
<input type="hidden" id="h1" value="h1">
<input type="hidden" id="h2" value="h2">
<input type="hidden" id="h3" value="h3">
</body>
</html>
-
jQuery程序的入口
$(document).ready(fn)
$(fn); -
this指针的作用 (demo4.jsp)
6.1 事件源(获取当前按钮的按钮值)
6.2 当前元素(点击按钮,获取所有a标签的值)
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<title>Insert title here</title>
<script type="text/javascript">
$(function() {//给input添加点击事件
$(":input").click(function() {
//this指的是事件源
alert(this.value);
$("a").each(function(index,item) {
//this指的是当前元素
alert(index+","+$(this).html()+","+$(item).html());
});
});
})
</script>
</head>
<body>
<p>
<a id="a1" class="c1" href="#">点我1</a>
</p>
<p>
<a id="a2" class="c2" href="#">点我2</a>
</p>
<p>
<a id="a3" class="c3" href="#">点我3</a>
</p>
<div>
<a id="a4" class="c1" href="#">点我4</a>
</div>
<div>
<p>
<a id="a5" class="c1" href="#">点我5</a>
</p>
</div>
<input type="button" value="ok">
</body>
</html>
- 使用jquery动态给table添加样式
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<style type="text/css">
.fen {
background: #ff66ff;
}
.yello {
background: #ffff66;
}
.red {
background: #ff3333;
}
</style>
<script type="text/javascript">
$(function() {
$("table tr:eq(0)").addClass("yello");
$("table tr:gt(0)").addClass("fen");
$("table tr:gt(0)").hover(function name() {
$(this).removeClass().addClass("fen");
},function(){
$(this).removeClass().addClass("red");
});
})
</script>
<title>Insert title here</title>
</head>
<body>
<table border="1" width="100%">
<tr>
<td>书名</td>
<td>作者</td>
<td>点击量</td>
</tr>
<tr>
<td>圣墟</td>
<td>辰东</td>
<td>10万</td>
</tr>
<tr>
<td>飞剑问道</td>
<td>我吃西红柿</td>
<td>11万</td>
</tr>
<tr>
<td>杀神</td>
<td>逆苍天</td>
<td>22万</td>
</tr>
<tr>
<td>龙王传说</td>
<td>唐家三少</td>
<td>18万</td>
</tr>
<tr>
<td>斗破苍穹</td>
<td>天蚕拖豆</td>
<td>1万</td>
</tr>
</table>
</body>
</html>
二.jquery插件
- 插件机制简介
往jquery类库里面去扩展方法,这类方法就是jquery插件 - json的三种格式
2.1 对象
{sid:‘s01’,sname:‘zs’}
2.2 列表/数组
[1,3,4,5]
2.3 混合模式
{id:3,hobby:[‘a’,‘b’,‘c’]}
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<script type="text/javascript">
$(function() {
//json对象的字符串体现形式
var jsonObj1={
sid:'s001',
sname:'zahngsan'
};
console.log(jsonObj1);
//json数组的字符串体现形式
var jsonArray1=[1,3,4,5];
console.log(jsonArray1);
//json混合模式的字符串体现形式
var jsons={id:3,hobby:['a','b','c']};
console.log(jsons);
})
</script>
<title>Insert title here</title>
</head>
<body>
</body>
</html>
-
.
e
x
t
e
n
d
和
.extend和
.extend和.fn.extend
2.1 $.extend:对象的扩展(或继承)
$.extend(obj1,obj2,obj3[,…])
$.extend(obj1,obj2)
. e x t e n d ( o b j 1 ) / .extend(obj1)/ .extend(obj1)/.method=function(options){…};
2.2 $.fn.extend
.
f
n
.
e
x
t
e
n
d
(
o
b
j
1
)
/
/
.fn.extend(obj1)//
.fn.extend(obj1)//.fn.method=function(options){…};
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<script type="text/javascript">
$(function() {
//$.extend是用来扩充jquery类属性或者方法所用
var jsonObj2={};
//用后面的对象扩充第一个对象
//$.extend(jsonObj2,jsonObj1);
//讲解扩充至覆盖的问题,之前已经扩充的属性值会被后面的对象所覆盖,如果后面的对象有新的属性,会继续扩充。
$.extend(jsonObj2,jsonObj1,jsonObj3);
console.log(jsonObj2);
$.extend({
hello:function(){
alert("我来了");
}
});
$.hello();
//$.fn.extend是用来扩充jquery实例属性或者方法所用
$.fn.extend({
sayHello:function(){
alert("我又来了");
}
});
$("#yellow").sayHello();
alert("yellow");
})
</script>
<title>Insert title here</title>
</head>
<body>
<span id="yellow">yellow</span>
</body>
</html>
- jQuery插件的添加
其实就是给jQuery添加新的实例方法或类方法,然后将功能封闭在其中
jquery.table.css
@charset "UTF-8";
.head {
background: #ff66ff;
}
.yellow {
background: #ffff66;
}
.red {
background: #ff3333;
}
.blue {
background: #9999ff;
}
.green {
background: #bbff99;
}
.hui {
background: #d6d6c2;
}
jquery.table.js
$(function() {
var defaults={
head:'fen',
out:'yellow',
over:'red'
}
$.fn.extend({
//使用return的原因是让该实例方法支持链编程,好比stringbuffer
bgColor:function(option){
$.extend(defaults,option);
//this指的是插件本身 可以看成一个jquery实例
return this.each(function(){
//this指的是当前元素
$("tr:eq(0)",this).addClass(defaults.head);
$("tr:gt(0)",this).addClass(defaults.out);
//添加动态效果
$("tr:gt(0)",this).hover(function(){
$(this).removeClass().addClass(defaults.over);
},function(){
$(this).removeClass().addClass(defaults.out);
});
});
}
});
})
jsp.common.head.jsp
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE>
<link href="${pageContext.request.contextPath }/jquery/table/css/jquery.table.css" type="text/css" rel="stylesheet"/>
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery.min.js"></script>
<script type="text/javascript" src="${pageContext.request.contextPath}/jquery/table/js/jquery.table.js"></script>
实例应用
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@include file="/jsp/common/head.jsp" %>
<!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=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
$(function(){
$("table").bgColor({
head:'yellow',
out:'red',
over:'green'
});
})
</script>
</head>
<body>
<table id="t1" border="1" width="100%">
<tr>
<td>书名</td>
<td>作者</td>
<td>点击量</td>
</tr>
<tr>
<td>圣墟</td>
<td>辰东</td>
<td>10万</td>
</tr>
<tr>
<td>飞剑问道</td>
<td>我吃西红柿</td>
<td>11万</td>
</tr>
<tr>
<td>杀神</td>
<td>逆苍天</td>
<td>22万</td>
</tr>
<tr>
<td>龙王传说</td>
<td>唐家三少</td>
<td>18万</td>
</tr>
<tr>
<td>斗破苍穹</td>
<td>天蚕拖豆</td>
<td>1万</td>
</tr>
</table>
<table id="t2" border="1" width="100%">
<tr>
<td>书名</td>
<td>作者</td>
<td>点击量</td>
</tr>
<tr>
<td>圣墟</td>
<td>辰东</td>
<td>10万</td>
</tr>
<tr>
<td>飞剑问道</td>
<td>我吃西红柿</td>
<td>11万</td>
</tr>
<tr>
<td>杀神</td>
<td>逆苍天</td>
<td>22万</td>
</tr>
<tr>
<td>龙王传说</td>
<td>唐家三少</td>
<td>18万</td>
</tr>
<tr>
<td>斗破苍穹</td>
<td>天蚕拖豆</td>
<td>1万</td>
</tr>
</table>
</body>
</html>
- jQuery插件开发实例(demo7.jsp demo8.jsp demo9.jsp)
4.1 命名
jquery.xxx.js
4.2 扩展实例方法
4.3 如何面向集合
4.4 如何多行集于一行
4.5 命名参数的写法
$.extend(defaults,options);
三.ajax
- jackson
Jackson是一个简单基于Java应用库,Jackson可以轻松的将Java对象转换成json对象
和xml文档,同样也可以将json、xml转换成Java对象
核心代码:
ObjectMapper mapper = new ObjectMapper();
mapper.writeValueAsString(obj);
int count = md.getColumnCount();
map.put(md.getColumnName(i), rs.getObject(i));
- jackson将java–>json
2.1 JavaBean/Map
{}
2.2 数组/List/Set
[]
2.3 类里嵌类
混合模式
package com.xfz.jquery;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.xfz.entity.Student;
/**
* @author ld
* 后台的json的三种格式的体现形式
*/
public class Demo1 {
public static void main(String[] args) throws JsonProcessingException {
//json对象
Student stu1=new Student("s001","张三");
ObjectMapper om=new ObjectMapper();
System.out.println(om.writeValueAsString(stu1));
//json数组
Student stu2=new Student("s002","李四");
List<Student> list1=new ArrayList<Student>();
list1.add(stu1);
list1.add(stu2);
System.out.println(om.writeValueAsString(list1));
//json混合格式
Map<String, Object> map=new HashMap<String, Object>();
map.put("total", 2);
map.put("stus", list1);
System.out.println(om.writeValueAsString(map));
}
}
- java->json死循环
忽略双向关联的一个方向即可
@JsonIgnore/程序控制
package com.xfz.jquery;
import java.util.HashSet;
import java.util.Set;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.xfz.entity.Student;
import com.xfz.entity.Teacher;
/**
* @author ld
* json死循环问题
* 1.由双向绑定改为单向绑定,也就是说将彼此之间的关系交于一方维护
* 2.@JsonIgnore:将彼此循环调用的属性忽略,不参与对象转成json格式
*/
public class Demo3 {
public static void main(String[] args) throws JsonProcessingException {
Student stu1 = new Student("s001", "张三");
Student stu2 = new Student("s002", "李四");
Teacher tea1 = new Teacher("t001", "王五", null);
Teacher tea2 = new Teacher("t002", "赵六", null);
Set<Teacher> teas = new HashSet<>();
teas.add(tea1);
teas.add(tea2);
stu1.setTeas(teas);
Set<Student> stus = new HashSet<>();
stus.add(stu1);
stus.add(stu2);
tea1.setStus(stus);
ObjectMapper om = new ObjectMapper();
System.out.println(om.writeValueAsString(stu1));
//运行结果:
//{"sid":"s001","sname":"张三","teas":[{"tid":"t002","sname":"赵六"},{"tid":"t001","sname":"王五"}]}
}
}
package com.xfz.jquery;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
/**
* @author ld
* javaBean与map集合转换成json字符串的格式是一样的
*/
public class Demo2 {
public static void main(String[] args) throws JsonProcessingException {
Map<String, Object> stu1=new HashMap<String, Object>();
stu1.put("sid", "s001");
stu1.put("sname", "张三");
ObjectMapper om=new ObjectMapper();
System.out.println(om.writeValueAsString(stu1));
//{"sname":"张三","sid":"s001"}
Map<String, Object> stu2=new HashMap<String, Object>();
stu2.put("sid", "s002");
stu2.put("sname", "李四");
List<Map<String, Object>> list1=new ArrayList<Map<String,Object>>();
list1.add(stu1);
list1.add(stu2);
System.out.println(om.writeValueAsString(list1));
//[{"sname":"张三","sid":"s001"},{"sname":"李四","sid":"s002"}]
}
}
四.省市级联动案例
连接数据库,导入之前所写到的类,导入jar包
RegionDao
package com.xfz.dao;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.xfz.util.JsonBaseDao;
import com.xfz.util.JsonUtils;
import com.xfz.util.PageBean;
import com.xfz.util.StringUtils;
public class RegionDao extends JsonBaseDao{
public List<Map<String , Object>> list(Map<String, String[]> paramMap,PageBean pageBean) throws InstantiationException, IllegalAccessException, SQLException{
//String [] strings=paramMap.get("sid");
String id = JsonUtils.getParamVal(paramMap, "ID");
String sql = "select * from ch_region where true";
if(StringUtils.isBlank(id)) {
sql += " and parent_id=7459";
}else {
sql += " and parent_id="+id;
}
return super.executeQuery(sql, pageBean);
}
public static void main(String[] args) {
Map<String,String[]> paramMap = new HashMap<>();
paramMap.put("ID", new String[] {"9504"});
RegionDao regionDao=new RegionDao();
try {
List<Map<String, Object>> list=regionDao.list(paramMap, null);
System.out.println(list);
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
RegionServlet
package com.xfz.web;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.xfz.dao.RegionDao;
import com.xfz.util.ResponseUtil;
public class RegionServlet extends HttpServlet{
private static final long serialVersionUID = -6226475440975457202L;
private RegionDao regionDao=new RegionDao();
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
try {
List<Map<String, Object>> list=regionDao.list(req.getParameterMap(), null);
ObjectMapper om=new ObjectMapper();
try {
ResponseUtil.write(resp, om.writeValueAsString(list));
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
专门用来处理json数据的工具包
package com.xfz.util;
import java.util.Arrays;
import java.util.Map;
/**
* @author Administrator
* 专门用来处理json数据的工具包
*
*/
public class JsonUtils {
/**
* 从paramMap拿到咱们所需要用到的查询维度,用于sql语句拼接
* @param paramMap 获取从jsp页面传递到后台的参数集合(req.getParamterMap)
* @param key
* @return
*/
public static String getParamVal(Map<String,String[]> paramMap, String key) {
if(paramMap != null && paramMap.size()>0) {
String[] vals = paramMap.get(key);
if(vals != null && vals.length > 0) {
String val = Arrays.toString(vals);
return val.substring(1, val.length()-1);
}
return "";
}
return "";
}
}
配置xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>web_jQuery</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>regionServlet</servlet-name>
<servlet-class>com.xfz.web.RegionServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>regionServlet</servlet-name>
<url-pattern>/regionServlet</url-pattern>
</servlet-mapping>
</web-app>
demo10.js
$(function(){
var ctx = $("#ctx").val();
$.ajax({
url:ctx+"/regionServlet",
success:function(data){
for(index in data){
//console.log(data[index]);
$("#province").append("<option value='"+data[index].ID+"'>"+data[index].REGION_NAME+"</option>");
}
},
dataType:"json"
});
$("#province").change(function(){
$("option:gt(0)","#city").remove();
$.ajax({
url:ctx+"/regionServlet?ID="+this.value,
success:function(data){
for(index in data){
//console.log(data[index]);
$("#city").append("<option value='"+data[index].ID+"'>"+data[index].REGION_NAME+"</option>");
}
},
dataType:"json"
});
});
})
jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="${pageContext.request.contextPath }/js/jquery.min.js"></script>
<script type="text/javascript" src="${pageContext.request.contextPath }/js/demo10.js"></script>
<title>Insert title here</title>
</head>
<body>
<div>
<input type="hidden" id="ctx" value="${pageContext.request.contextPath}">
<h1>$.ajax实现省市联动</h1>
<div>
收货地址
<select id="province">
<option selected="selected">---请选择省份---</option>
</select>
<select id="city">
<option selected="selected">---请选择城市---</option>
</select>
<select id=" county">
<option selected="selected">---请选择县区---</option>
</select>
</div>
</div>
</body>
</html>
显示: