Ajax实现省市无穷级联动

本文主要是介绍Ajax实现省市无穷级联动，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

这是一个Servlet应用。。

这里用到了Json-lib工具包，关于Json-lib的使用，请参见我的博文

http://blog.csdn.net/jadyer/archive/2011/02/01/6171659.aspx

首先是web.xml文件

<?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"> <servlet> <servlet-name>InitProvinceServlet</servlet-name> <servlet-class>com.jadyer.servlet.InitProvinceServlet</servlet-class> </servlet> <servlet> <servlet-name>GetCityServlet</servlet-name> <servlet-class>com.jadyer.servlet.GetCityServlet</servlet-class> </servlet> <servlet> <servlet-name>GetAreaServlet</servlet-name> <servlet-class>com.jadyer.servlet.GetAreaServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>InitProvinceServlet</servlet-name> <url-pattern>/servlet/InitProvinceServlet</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>GetCityServlet</servlet-name> <url-pattern>/servlet/GetCityServlet</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>GetAreaServlet</servlet-name> <url-pattern>/servlet/GetAreaServlet</url-pattern> </servlet-mapping> <!-- 在version="2.5"中，可以直接在<welcome-file-list>里执行Servlet应用 --> <welcome-file-list> <welcome-file>servlet/InitProvinceServlet</welcome-file> </welcome-file-list> </web-app>

然后是用来显示省市无穷级联动效果的index.jsp页面

<%@ page language="java" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <script type="text/javascript"> var xmlHTTP = new XMLHttpRequest(); //支持Internet Explorer-8.0.6001.18702 var theTagID; //定义的全局变量，以便于在回调函数中使用之 function getCityList(provinceID, tagID){ var isDelete = false; theTagID = tagID; var sons = document.getElementById(tagID).childNodes; for(var i=(sons.length-1); i>=0; i--){ if("A" != sons[i].nodeName.toUpperCase()){ //if("UL" == sons[i].nodeName.toUpperCase()){ //二者等效 sons[i].parentNode.removeChild(sons[i]); isDelete = true; } } if(isDelete){ return; } xmlHTTP.open('GET', '${pageContext.request.contextPath}/servlet/GetCityServlet?provinceID='+provinceID, true); xmlHTTP.onreadystatechange = callbackCityList; xmlHTTP.setRequestHeader("if-Modified-Since", "0"); xmlHTTP.send(null); return false; } function callbackCityList(){ if(4==xmlHTTP.readyState && 200==xmlHTTP.status){ var citys = eval(xmlHTTP.responseText); if(0 == citys.length){ return; } var parentLI = document.getElementById(theTagID); var newUL = document.createElement("ul"); for(var i=0; i<citys.length; i++){ var newLI = document.createElement("li"); newLI.id = "tag" + citys[i].cityID; newLI.innerHTML = "<a href='#' οnclick='getCityList(" + citys[i].cityID + ", /"tag" + citys[i].cityID + "/");'>" + citys[i].cityName + "</a>"; newUL.appendChild(newLI); } parentLI.appendChild(newUL); } } </script> <ul> <c:forEach items="${requestScope.provinces}" var="province"> <li id="tag${province.cityID}"><a href="#" οnclick="return getCityList(${province.cityID}, 'tag${province.cityID}');">${province.cityName}</a></li> </c:forEach> </ul>

然后是用于从数据库执行查询操作的CityDao.java

package com.jadyer.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; import javax.sql.DataSource; import com.jadyer.model.City; /** * 这里的代码，应该重构一下，但为了演示方便，就没有重构 */ public class CityDao { /** * 根据父ID得到所有一级子类 * @see 如果传递为0，则得到所有根节点 */ public List<City> findByParentID(int parentID){ String sql = "select cityID, cityName from city where parentID=?"; List<City> citys = new ArrayList<City>(); try { Context context = new InitialContext(); //有关jdbc/oracleds连接池的配置，参见http://blog.csdn.net/jadyer/archive/2010/11/10/6001023.aspx DataSource ds = (DataSource)context.lookup("java:/comp/env/jdbc/oracleds"); Connection conn = ds.getConnection(); PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.setInt(1, parentID); ResultSet rs = pstmt.executeQuery(); while(rs.next()){ citys.add(new City(rs.getInt("cityID"), rs.getString("cityName"))); } } catch (NamingException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return citys; } /** * 根据ID得到该城市的详细信息 */ public City fingByCityID(int cityID){ String sql = "select cityName from city where cityID=?"; City city = null; try { Context context = new InitialContext(); DataSource ds = (DataSource)context.lookup("java:/comp/env/jdbc/oracleds"); Connection conn = ds.getConnection(); PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.setInt(1, cityID); ResultSet rs = pstmt.executeQuery(); while(rs.next()){ city = new City(cityID, rs.getString("cityName")); } } catch (NamingException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return city; } }

用于储存City信息的实体类

package com.jadyer.model; import java.util.List; public class City { private Integer parentID; private Integer cityID; private String cityName; private List<City> areas; //用于储存该城市下所有区县的详细信息 /* 四个属性的getter和setter方法略 */ public City(){} public City(Integer cityID, String cityName){ this.cityID = cityID; this.cityName = cityName; } }

用于初始化所有省份信息的InitProvinceServlet.java

package com.jadyer.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.jadyer.dao.CityDao; @SuppressWarnings("serial") public class InitProvinceServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { CityDao cityDao = new CityDao(); //获取所有省份的信息 request.setAttribute("provinces", cityDao.findByParentID(0)); request.getRequestDispatcher("/index.jsp").forward(request, response); } }

用于获取指定省份下的所有城市信息的GetCityServlet.java

package com.jadyer.servlet; import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.sf.json.JSONArray; import com.jadyer.dao.CityDao; import com.jadyer.model.City; @SuppressWarnings("serial") public class GetCityServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { response.setContentType("text/html; charset=UTF-8"); int provinceID = Integer.parseInt(request.getParameter("provinceID")); CityDao cityDao = new CityDao(); //返回该省份下的所有城市的信息 List<City> citys = cityDao.findByParentID(provinceID); JSONArray jsonObject = JSONArray.fromObject(citys); response.getWriter().println(jsonObject.toString()); } }

用于获取指定城市下的所有区县信息的GetAreaServlet.java

package com.jadyer.servlet; import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.sf.json.JSONObject; import com.jadyer.dao.CityDao; import com.jadyer.model.City; @SuppressWarnings("serial") public class GetAreaServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { response.setContentType("text/html; charset=UTF-8"); int cityID = Integer.parseInt(request.getParameter("cityID")); CityDao cityDao = new CityDao(); //得到该城市下所有区县的详细信息的集合 List<City> areas = cityDao.findByParentID(cityID); //得到当前城市的详细信息 City city22 = cityDao.fingByCityID(cityID); city22.setAreas(areas); JSONObject jsonObject = JSONObject.fromObject(city22); response.getWriter().println(jsonObject.toString()); } }

最后是数据库脚本文件

--Oracle 11g --创建表格 create table city( id number(3) primary key, parentID number(3), --0表示根节点 cityID number(3), cityName varchar(20) ) --创建序列 create sequence city_sequence increment by 1 start with 1 nomaxvalue nocycle; --添加一级菜单 insert into city values(city_sequence.nextval, 0, 1, '黑龙江'); insert into city values(city_sequence.nextval, 0, 2, '吉林省'); insert into city values(city_sequence.nextval, 0, 3, '辽宁省'); --添加二级菜单 insert into city values(city_sequence.nextval, 1, 4, '哈尔滨'); insert into city values(city_sequence.nextval, 1, 5, '佳木斯'); insert into city values(city_sequence.nextval, 1, 6, '双鸭山'); insert into city values(city_sequence.nextval, 2, 7, '长春'); insert into city values(city_sequence.nextval, 2, 8, '辽源'); insert into city values(city_sequence.nextval, 2, 9, '通化'); insert into city values(city_sequence.nextval, 3, 10, '沈阳'); insert into city values(city_sequence.nextval, 3, 11, '大连'); insert into city values(city_sequence.nextval, 3, 12, '铁岭'); --添加三级菜单 --这里只提供了黑龙江省的三级联动数据，关于其它省份的数据，请自行添加 insert into city values(city_sequence.nextval, 4, 13, '巴彦县'); insert into city values(city_sequence.nextval, 4, 14, '延寿县'); insert into city values(city_sequence.nextval, 4, 15, '木兰县'); insert into city values(city_sequence.nextval, 5, 16, '抚远县'); insert into city values(city_sequence.nextval, 5, 17, '汤原县'); insert into city values(city_sequence.nextval, 5, 18, '桦川县'); insert into city values(city_sequence.nextval, 6, 19, '集贤县'); insert into city values(city_sequence.nextval, 6, 20, '宝清县'); insert into city values(city_sequence.nextval, 6, 21, '友谊县'); --添加四级菜单 --这里只提供了哈尔滨市的四级联动数据，其它数据，请自行添加 insert into city values(city_sequence.nextval, 13, 22, '兴隆镇'); insert into city values(city_sequence.nextval, 13, 23, '龙庙镇'); insert into city values(city_sequence.nextval, 13, 24, '洼兴镇'); insert into city values(city_sequence.nextval, 14, 25, '六团镇'); insert into city values(city_sequence.nextval, 14, 26, '中和镇'); insert into city values(city_sequence.nextval, 14, 27, '加信镇'); insert into city values(city_sequence.nextval, 15, 28, '东兴镇'); insert into city values(city_sequence.nextval, 15, 29, '大贵镇'); insert into city values(city_sequence.nextval, 15, 30, '新民镇'); --添加五级菜单 --这里只提供了巴彦县的五级联动数据，其它数据，请自行添加 insert into city values(city_sequence.nextval, 22, 31, '长春乡'); insert into city values(city_sequence.nextval, 22, 32, '丰乐乡'); insert into city values(city_sequence.nextval, 22, 33, '德祥乡'); insert into city values(city_sequence.nextval, 23, 34, '山后乡'); insert into city values(city_sequence.nextval, 23, 35, '华山乡'); insert into city values(city_sequence.nextval, 23, 36, '红光乡'); insert into city values(city_sequence.nextval, 24, 36, '镇东乡'); insert into city values(city_sequence.nextval, 24, 36, '富江乡'); insert into city values(city_sequence.nextval, 24, 36, '松花乡'); --添加六级菜单 --理论上可无限添加。但实际中，用到四级菜单的情况都不是太多，故以下数据略

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