search
HomeWeb Front-endJS TutorialAjax realizes three-level cascading of provinces and municipalities (data comes from mysql database)

This article mainly introduces Ajax to realize the three-level cascade of provinces and municipalities in detail. The data comes from mysql database. It has certain reference and value for learning Ajax. Friends who are interested in ajax You can refer to

Implementing Ajax to realize three-level cascading of provinces and municipalities requires Java parsing json technology
The overall Demo download address is as follows: Click me to download

address.html


<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>

 <script type="text/javascript">

  /** 
   * 得到XMLHttpRequest对象 
   */
  function getajaxHttp() {
   var xmlHttp;
   try {
    // Firefox, Opera 8.0+, Safari 
    xmlHttp = new XMLHttpRequest();
   } catch (e) {
    // Internet Explorer 
    try {
     xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
     try {
      xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
     } catch (e) {
      alert("您的浏览器不支持AJAX!");
      return false;
     }
    }
   }
   return xmlHttp;
  }
  /** 
   * 发送ajax请求 
   * url--请求到服务器的URL 
   * methodtype(post/get) 
   * con (true(异步)|false(同步)) 
   * functionName(回调方法名,不需要引号,这里只有成功的时候才调用) 
   * (注意:这方法有二个参数,一个就是xmlhttp,一个就是要处理的对象) 
   */
  function ajaxrequest(url, methodtype, con, functionName) {
   //获取XMLHTTPRequest对象
   var xmlhttp = getajaxHttp();
   //设置回调函数(响应的时候调用的函数)
   xmlhttp.onreadystatechange = function() {
    //这个函数中的代码在什么时候被XMLHTTPRequest对象调用?
    //当服务器响应时,XMLHTTPRequest对象会自动调用该回调方法
    if (xmlhttp.readyState == 4) {
     if (xmlhttp.status == 200) {
      functionName(xmlhttp.responseText);
     }
    }
   };
   //创建请求
   xmlhttp.open(methodtype, url, con);
   //发送请求
   xmlhttp.send();
  }

  window.onload=function(){
   ajaxrequest("addressSerlvet?method=provincial","POST",true,addrResponse);
  }
  //动态获取省的信息
  function addrResponse(responseContents){
   var jsonObj = new Function("return" + responseContents)();
   for(var i = 0; i < jsonObj.addrList.length;i++){
    document.getElementById(&#39;select&#39;).innerHTML += 
     "<option value=&#39;"+jsonObj.addrList[i].id+"&#39;>"
      +jsonObj.addrList[i].address+
     "</option>"
   }
  }
  //选中省后
  function pChange(){
   //先将市的之前的信息清除
   document.getElementById(&#39;selectCity&#39;).innerHTML="<option value=&#39;-1&#39;>请选择市</option>";
   //再将区的信息清除
   document.getElementById(&#39;selectArea&#39;).innerHTML="<option value=&#39;-1&#39;>请选择区</option>";
   //再将用户的输入清楚
   document.getElementById("addr").innerHTML="";
   var val = document.getElementById(&#39;select&#39;).value;
   if(val == -1){
    document.getElementById(&#39;selectCity&#39;)[0].selected = true;
    return;
   }
   //开始执行获取市
   ajaxrequest("addressSerlvet?method=city&provincial="+val,"POST",true,cityResponse);
  }
  //获取市的动态数据
  function cityResponse(responseContents){
   var jsonObj = new Function("return" + responseContents)();
   for(var i = 0; i < jsonObj.cityList.length;i++){
    document.getElementById(&#39;selectCity&#39;).innerHTML += 
     "<option value=&#39;"+jsonObj.cityList[i].id+"&#39;>"
      +jsonObj.cityList[i].address+
     "</option>"
   }
  }
  //选中市以后
  function cChange(){
   var val = document.getElementById(&#39;selectCity&#39;).value;
   //开始执行获取区
   ajaxrequest("addressSerlvet?method=area&cityId="+val,"POST",true,areaResponse);
  }
  //获取区的动态数据
  function areaResponse(responseContents){
   var jsonObj = new Function("return" + responseContents)();
   for(var i = 0; i < jsonObj.areaList.length;i++){
    document.getElementById(&#39;selectArea&#39;).innerHTML += 
     "<option value=&#39;"+jsonObj.areaList[i].id+"&#39;>"
      +jsonObj.areaList[i].address+
     "</option>"
   }
  }
  //点击提交按钮
  function confirM(){
   //获取省的文本值
   var p = document.getElementById("select");
   var pTex = p.options[p.options.selectedIndex].text;
   if(p.value=-1){
    alert("请选择省");
    return;
   }
   //获取市的文本值
   var city = document.getElementById("selectCity");
   var cityTex = city.options[city.options.selectedIndex].text;
   if(city.value=-1){
    alert("请选择市");
    return;
   }
   //获取区的文本值
   var area = document.getElementById("selectArea");
   var areaTex = area.options[area.options.selectedIndex].text;
   if(area.value=-1){
    alert("请选择区");
    return;
   }
   //获取具体位置id文本值
   var addr = document.getElementById("addr").value;
   //打印
   document.getElementById("show").innerHTML = "您选择的地址为 " + pTex + " " + cityTex + " " + areaTex + " " + addr;
  }

 </script>
<body>
 <select id="select" onchange="pChange()">
  <option value="-1">请选择省</option>
 </select>
 <select id="selectCity" onchange="cChange()">
  <option value=&#39;-1&#39;>请选择市</option>
 </select>
 <select id="selectArea" onchange="aChange()">
  <option value=&#39;-1&#39;>请选择市</option>
 </select>
 <input type="text" id="addr" />
 <button onclick="confirM();">确定</button>
 <p id="show"></p>
</body>
</html>


AddressServlet.java



package cn.bestchance.servlet;

import java.io.IOException;
import java.util.ArrayList;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.bestchance.dao.AddressDao;
import cn.bestchance.dao.impl.AddressDaoImpl;
import cn.bestchance.entity.Address;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

@WebServlet("/addressSerlvet")
public class AddressSerlvet extends HttpServlet {
 private static final long serialVersionUID = 1L;
 private AddressDao dao = new AddressDaoImpl();

 protected void doGet(HttpServletRequest request,
   HttpServletResponse response) throws ServletException, IOException {
  doPost(request, response);
 }

 /**
  * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
  *  response)
  */
 protected void doPost(HttpServletRequest request,
   HttpServletResponse response) throws ServletException, IOException {

  response.setCharacterEncoding("utf-8");
  response.setContentType("text/html;charset=utf-8");
  String method=request.getParameter("method");
  if("provincial".equals(method)){
   getProvincial(request, response);
  }
  if("city".equals(method)){
   getCity(request, response);
  }
  if("area".equals(method)){
   getArea(request, response);
  }
 }
 /**
  * 根据市id获取该市下的区的全部信息
  * @param request
  * @param response
  * @throws ServletException
  * @throws IOException
  */
 protected void getArea(HttpServletRequest request,
   HttpServletResponse response) throws ServletException, IOException {

  String cityId = request.getParameter("cityId");
  // 从数据库中查询省的信息
  ArrayList<Address> areaList = dao.getAreaByCityId(Integer.parseInt(cityId));
  // 将集合转成json字符串
  JSONObject jsonObj = new JSONObject();
  JSONArray jsonArray = JSONArray.fromObject(areaList);
  jsonObj.put("areaList", jsonArray);
  String jsonDataStr = jsonObj.toString();

  response.getWriter().print(jsonDataStr);
 }
 /**
  * 获取省的信息 并相应
  * @param request
  * @param response
  * @throws ServletException
  * @throws IOException
  */
 protected void getProvincial(HttpServletRequest request,
   HttpServletResponse response) throws ServletException, IOException {

  // 从数据库中查询省的信息
  ArrayList<Address> addrList = dao.getProvince();
  // 将集合转成json字符串
  JSONObject jsonObj = new JSONObject();
  JSONArray jsonArray = JSONArray.fromObject(addrList);
  jsonObj.put("addrList", jsonArray);
  String jsonDataStr = jsonObj.toString();
  response.getWriter().print(jsonDataStr);
 }
 /**
  * 获取市的信息并相应
  * @param request
  * @param response
  * @throws ServletException
  * @throws IOException
  */
 protected void getCity(HttpServletRequest request,
   HttpServletResponse response) throws ServletException, IOException {

  String provinceId = request.getParameter("provincial");
  // 从数据库中查询省的信息
  ArrayList<Address> addrList = dao.getCityByProvinceId(Integer.parseInt(provinceId));

  // 将集合转成json字符串
  JSONObject jsonObj = new JSONObject();
  JSONArray jsonArray = JSONArray.fromObject(addrList);
  jsonObj.put("cityList", jsonArray);
  String jsonDataStr = jsonObj.toString();

  response.getWriter().print(jsonDataStr);
 }

}


AddressDao.java



package cn.bestchance.dao;

import java.util.ArrayList;

import cn.bestchance.entity.Address;

public interface AddressDao {
 /**
  * 获取省的id和名称
  * @return
  */
 ArrayList<Address> getProvince();
 /**
  * 根据省的id获取市的信息
  * @param provinceId
  * @return
  */
 ArrayList<Address> getCityByProvinceId(int provinceId);
 /**
  * 根据市的id获取区的信息
  * @param cityId
  * @return
  */
 ArrayList<Address> getAreaByCityId(int cityId);
}


AddressDaoImpl.java



package cn.bestchance.dao.impl;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import cn.bestchance.dao.AddressDao;
import cn.bestchance.entity.Address;
import cn.bestchance.util.DBUtil;

public class AddressDaoImpl implements AddressDao {
 private DBUtil db = new DBUtil();
 @Override
 public ArrayList<Address> getProvince() {
  ArrayList<Address> addrList = new ArrayList<Address>();
  db.openConnection();
  String sql = "select * from province";
  ResultSet rs = db.excuteQuery(sql);
  try {
   while(rs.next()){
    Address addr = new Address();
    addr.setId(rs.getInt(2));
    addr.setAddress(rs.getString(3));
    addrList.add(addr);
   }
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally{
   if(rs != null){
    try {
     rs.close();
    } catch (SQLException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   db.closeResoure();
  }
  return addrList;
 }
 @Override
 public ArrayList<Address> getCityByProvinceId(int provinceId) {
  ArrayList<Address> addrList = new ArrayList<Address>();
  db.openConnection();
  String sql = "select * from city where fatherID = " + provinceId; //431200
  ResultSet rs = db.excuteQuery(sql);
  try {
   while(rs.next()){
    Address addr = new Address();
    addr.setId(rs.getInt(2));
    addr.setAddress(rs.getString(3));
    addrList.add(addr);
   }
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally{
   if(rs != null){
    try {
     rs.close();
    } catch (SQLException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   db.closeResoure();
  }
  return addrList;
 }
 @Override
 public ArrayList<Address> getAreaByCityId(int cityId) {
  ArrayList<Address> addrList = new ArrayList<Address>();
  db.openConnection();
  String sql = "select * from area where fatherID = " + cityId; //431200
  ResultSet rs = db.excuteQuery(sql);
  try {
   while(rs.next()){
    Address addr = new Address();
    addr.setId(rs.getInt(2));
    addr.setAddress(rs.getString(3));
    addrList.add(addr);
   }
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally{
   if(rs != null){
    try {
     rs.close();
    } catch (SQLException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
   db.closeResoure();
  }
  return addrList;
 }

}


Entity class Address.java



package cn.bestchance.entity;

public class Address {
 @Override
 public String toString() {
  return "Address [id=" + id + ", address=" + address + "]";
 }
 private int id;
 private String address;
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public String getAddress() {
  return address;
 }
 public void setAddress(String address) {
  this.address = address;
 }
 public Address() {
  super();
  // TODO Auto-generated constructor stub
 }
 public Address(int id, String address) {
  super();
  this.id = id;
  this.address = address;
 }

}


The above is the entire content of this article. I hope it will be helpful to everyone's learning, and I also hope that everyone will support the PHP Chinese website.

Related recommendations:

jq, ajax, php, mysql to implement keyword fuzzy query

Simple implementation of Ajax without refresh Pagination effect

The perfect solution for Ajax cross-domain requests that COOKIE cannot bring

The above is the detailed content of Ajax realizes three-level cascading of provinces and municipalities (data comes from mysql database). For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Scrapy基于Ajax异步加载实现方法Scrapy基于Ajax异步加载实现方法Jun 22, 2023 pm 11:09 PM

Scrapy是一个开源的Python爬虫框架,它可以快速高效地从网站上获取数据。然而,很多网站采用了Ajax异步加载技术,使得Scrapy无法直接获取数据。本文将介绍基于Ajax异步加载的Scrapy实现方法。一、Ajax异步加载原理Ajax异步加载:在传统的页面加载方式中,浏览器发送请求到服务器后,必须等待服务器返回响应并将页面全部加载完毕才能进行下一步操

如何使用CakePHP中的AJAX?如何使用CakePHP中的AJAX?Jun 04, 2023 pm 08:01 PM

作为一种基于MVC模式的PHP框架,CakePHP已成为许多Web开发人员的首选。它的结构简单,易于扩展,而其中的AJAX技术更是让开发变得更加高效。在本文中,将介绍如何使用CakePHP中的AJAX。什么是AJAX?在介绍如何在CakePHP中使用AJAX之前,我们先来了解一下什么是AJAX。AJAX是“异步JavaScript和XML”的缩写,是指一种在

jquery ajax报错403怎么办jquery ajax报错403怎么办Nov 30, 2022 am 10:09 AM

jquery ajax报错403是因为前端和服务器的域名不同而触发了防盗链机制,其解决办法:1、打开相应的代码文件;2、通过“public CorsFilter corsFilter() {...}”方法设置允许的域即可。

ajax传递中文乱码怎么办ajax传递中文乱码怎么办Nov 15, 2023 am 10:42 AM

ajax传递中文乱码的解决办法:1、设置统一的编码方式;2、服务器端编码;3、客户端解码;4、设置HTTP响应头;5、使用JSON格式。详细介绍:1、设置统一的编码方式,确保服务器端和客户端使用相同的编码方式,通常情况下,UTF-8是一种常用的编码方式,因为它可以支持多种语言和字符集;2、服务器端编码,在服务器端,确保将中文数据以正确的编码方式进行编码,再传递给客户端等等。

Nginx中404页面怎么配置及AJAX请求返回404页面Nginx中404页面怎么配置及AJAX请求返回404页面May 26, 2023 pm 09:47 PM

404页面基础配置404错误是www网站访问容易出现的错误。最常见的出错提示:404notfound。404错误页的设置对网站seo有很大的影响,而设置不当,比如直接转跳主页等,会被搜索引擎降权拔毛。404页面的目的应该是告诉用户:你所请求的页面是不存在的,同时引导用户浏览网站其他页面而不是关掉窗口离去。搜索引擎通过http状态码来识别网页的状态。当搜索引擎获得了一个错误链接时,网站应该返回404状态码,告诉搜索引擎放弃对该链接的索引。而如果返回200或302状态码,搜索引擎就会为该链接建立索引

什么是ajax重构什么是ajax重构Jul 01, 2022 pm 05:12 PM

ajax重构指的是在不改变软件现有功能的基础上,通过调整程序代码改善软件的质量、性能,使其程序的设计模式和架构更合理,提高软件的扩展性和维护性;Ajax的实现主要依赖于XMLHttpRequest对象,由于该对象的实例在处理事件完成后就会被销毁,所以在需要调用它的时候就要重新构建。

在Laravel中如何通过Ajax请求传递CSRF令牌?在Laravel中如何通过Ajax请求传递CSRF令牌?Sep 10, 2023 pm 03:09 PM

CSRF代表跨站请求伪造。CSRF是未经授权的用户冒充授权执行的恶意活动。Laravel通过为每个活动用户会话生成csrf令牌来保护此类恶意活动。令牌存储在用户的会话中。如果会话发生变化,它总是会重新生成,因此每个会话都会验证令牌,以确保授权用户正在执行任何任务。以下是访问csrf_token的示例。生成csrf令牌您可以通过两种方式获取令牌。通过使用$request→session()→token()直接使用csrf_token()方法示例<?phpnamespaceApp\Http\C

使用HTML5文件上传与AJAX和jQuery使用HTML5文件上传与AJAX和jQuerySep 13, 2023 am 10:09 AM

当提交表单时,捕获提交过程并尝试运行以下代码片段来上传文件-//File1varmyFile=document.getElementById(&#39;fileBox&#39;).files[0];varreader=newFileReader();reader.readAsText(file,&#39;UTF-8&#39;);reader.onload=myFunc;functionmyFunc(event){&nbsp;&nbsp;varres

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool