ajax|Ajax省市区三级联动
需要的jar包： 
文章图片
文章图片
数据库代码：
create database school character set utf8;
use school;
CREATE tableprovice (
pid INT PRIMARY KEYauto_increment,
pname varchar(20));
INSERT into provice VALUES (null,"河南省");
INSERT into provice VALUES (null,"山东省");
INSERT into provice VALUES (null,"河北省");
CREATE tablecity (
cid INT PRIMARY KEYauto_increment,
cname varchar(20),
pid int
);
-- 河南省
INSERT into city VALUES (null,"郑州市",1);
INSERT into city VALUES (null,"开封市",1);
INSERT into city VALUES (null,"洛阳市",1);
-- 山东
INSERT into city VALUES (null,"济南市",2);
INSERT into city VALUES (null,"青岛市",2);
INSERT into city VALUES (null,"淄博市",2);
-- 河北
INSERT into city VALUES (null,"石家庄市",3);
INSERT into city VALUES (null,"唐山市",3);
INSERT into city VALUES (null,"秦皇岛市",3);
CREATE tablestreet (
sid INT PRIMARY KEYauto_increment,
sname varchar(20),
cid int
);
-- 郑州市
INSERT into street VALUES (null,"中原区",1);
INSERT into street VALUES (null,"二七区",1);
INSERT into street VALUES (null,"管城回族区",1);
-- 开封市
INSERT into street VALUES (null,"龙亭区",2);
INSERT into street VALUES (null,"顺河回族区",2);
INSERT into street VALUES (null,"鼓楼区",2);
-- 洛阳市
INSERT into street VALUES (null,"汝阳",3);
INSERT into street VALUES (null,"宜阳",3);
INSERT into street VALUES (null,"洛宁",3);
-- 济南市
INSERT into street VALUES (null,"商河县",4);
INSERT into street VALUES (null,"济阳县",4);
INSERT into street VALUES (null,"平阴县",4);
-- 青岛市
INSERT into street VALUES (null,"七区五市",5);
INSERT into street VALUES (null,"市南区",5);
INSERT into street VALUES (null,"市北区",5);
-- 淄博市
INSERT into street VALUES (null,"博山",6);
INSERT into street VALUES (null,"周村",6);
INSERT into street VALUES (null,"临淄",6);
-- 石家庄市
INSERT into street VALUES (null,"正定县",7);
INSERT into street VALUES (null,"行唐县",7);
INSERT into street VALUES (null,"灵寿县",7);
-- 唐山市
INSERT into street VALUES (null,"乐亭县",8);
INSERT into street VALUES (null,"迁西县",8);
INSERT into street VALUES (null,"玉田县",8);
-- 秦皇岛市
INSERT into street VALUES (null,"青龙满族自治县",9);
INSERT into street VALUES (null,"昌黎县",9);
INSERT into street VALUES (null,"卢龙县",9);
省：
package cn.hp.dao;
import cn.hp.model.Provice;
import java.util.List;
public interface ProviceInfoDao {
public List findAll();
}
package cn.hp.impl;
import cn.hp.dao.ProviceInfoDao;
import cn.hp.model.Provice;
import cn.hp.util.DBHelper;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class ProviceInfoDaoImpl implements ProviceInfoDao {
@Override
public List【ajax|Ajax省市区三级联动】 findAll() {
Connection conn = DBHelper.getConn();
List list = new ArrayList();
String sql = "select * from provice";
try {
PreparedStatement ps=conn.prepareStatement(sql);
ResultSet rs = ps.executeQuery();
while (rs.next()){
Provice p = new Provice();
p.setPid(rs.getInt(1));
p.setPname(rs.getString(2));
list.add(p);
}
} catch (SQLException e) {
e.printStackTrace();
}
return list;
}
}
package cn.hp.model;
public class Provice {
private int pid;
private String pname;
public Provice() {
}public Provice(int pid, String pname) {
this.pid = pid;
this.pname = pname;
}@Override
public String toString() {
return "Provice{" +
"pid=" + pid +
", pname='" + pname + '\'' +
'}';
}public int getPid() {
return pid;
}public void setPid(int pid) {
this.pid = pid;
}public String getPname() {
return pname;
}public void setPname(String pname) {
this.pname = pname;
}
}
package cn.hp.servlet;
import cn.hp.dao.ProviceInfoDao;
import cn.hp.impl.ProviceInfoDaoImpl;
import cn.hp.model.Provice;
import com.alibaba.fastjson.JSONObject;
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 java.io.IOException;
import java.util.List;
@WebServlet("/findprovice")
public class FindProviceServlet extends HttpServlet {
public FindProviceServlet() {
super();
}@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//super.doGet(req, resp);
req.setCharacterEncoding("utf-8");
resp.setContentType("text/html;
charset=utf-8");
ProviceInfoDao pid = new ProviceInfoDaoImpl();
List plist=pid.findAll();
//把这个省份的集合转换成json格式的数据发送到前端页面
resp.getWriter().write(JSONObject.toJSONString(plist));
}@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
super.doPost(req, resp);
}}
市：
package cn.hp.dao;
import cn.hp.model.City;
import java.util.List;
public interface CityInfoDao {
public List findAllCity(int pid);
}
package cn.hp.impl;
import cn.hp.dao.CityInfoDao;
import cn.hp.model.City;
import cn.hp.model.Provice;
import cn.hp.util.DBHelper;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class CityInfoDaoImpl implements CityInfoDao {
@Override
public List findAllCity(int pid) {
Connection conn = DBHelper.getConn();
List list = new ArrayList();
String sql = "select * from city where pid=?";
try {
PreparedStatement ps=conn.prepareStatement(sql);
ps.setInt(1,pid);
ResultSet rs = ps.executeQuery();
while (rs.next()){
City c=new City();
c.setCid(rs.getInt(1));
c.setCname(rs.getString(2));
c.setPid(rs.getInt(3));
list.add(c);
}
} catch (SQLException e) {
e.printStackTrace();
}
return list;
}
}
package cn.hp.model;
public class City {
private int cid;
private String cname;
private int pid;
public City() {
}public City(int cid, String cname, int pid) {
this.cid = cid;
this.cname = cname;
this.pid = pid;
}@Override
public String toString() {
return "City{" +
"cid=" + cid +
", cname='" + cname + '\'' +
", pid=" + pid +
'}';
}public int getCid() {
return cid;
}public void setCid(int cid) {
this.cid = cid;
}public String getCname() {
return cname;
}public void setCname(String cname) {
this.cname = cname;
}public int getPid() {
return pid;
}public void setPid(int pid) {
this.pid = pid;
}
}
package cn.hp.servlet;
import cn.hp.dao.CityInfoDao;
import cn.hp.impl.CityInfoDaoImpl;
import cn.hp.model.City;
import com.alibaba.fastjson.JSONObject;
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 java.io.IOException;
import java.util.List;
@WebServlet("/findcitypid")
public class FindCityPidServlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
resp.setContentType("text/html;
charset=utf-8");
String id = req.getParameter("id");
CityInfoDao cid = new CityInfoDaoImpl();
List list = cid.findAllCity(Integer.parseInt(id));
//把城市的集合转换成json格式的字符串发送到前端页面
resp.getWriter().write(JSONObject.toJSONString(list));
}@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
super.doPost(req, resp);
}
}
区：
package cn.hp.dao;
import cn.hp.model.Street;
import java.util.List;
public interface StreetInfoDao {
public List findAllStreet(int cid);
}
package cn.hp.impl;
import cn.hp.dao.StreetInfoDao;
import cn.hp.model.Provice;
import cn.hp.model.Street;
import cn.hp.util.DBHelper;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class StreetInfoDaoImpl implements StreetInfoDao {
@Override
public List findAllStreet(int cid) {
Connection conn = DBHelper.getConn();
List list = new ArrayList();
String sql = "select * from Street where cid=?";
try {
PreparedStatement ps=conn.prepareStatement(sql);
ps.setInt(1,cid);
ResultSet rs = ps.executeQuery();
while (rs.next()){
Street s = new Street();
s.setDid(rs.getInt(1));
s.setDname(rs.getString(2));
s.setCid(rs.getInt(3));
list.add(s);
}
} catch (SQLException e) {
e.printStackTrace();
}
return list;
}
}
package cn.hp.model;
public class Street {
private int did;
private String dname;
private int cid;
public Street() {
}public Street(int did, String dname, int cid) {
this.did = did;
this.dname = dname;
this.cid = cid;
}@Override
public String toString() {
return "Street{" +
"did=" + did +
", dname='" + dname + '\'' +
", cid=" + cid +
'}';
}public int getDid() {
return did;
}public void setDid(int did) {
this.did = did;
}public String getDname() {
return dname;
}public void setDname(String dname) {
this.dname = dname;
}public int getCid() {
return cid;
}public void setCid(int cid) {
this.cid = cid;
}
}
package cn.hp.servlet;
import cn.hp.dao.CityInfoDao;
import cn.hp.dao.ProviceInfoDao;
import cn.hp.dao.StreetInfoDao;
import cn.hp.impl.CityInfoDaoImpl;
import cn.hp.impl.ProviceInfoDaoImpl;
import cn.hp.impl.StreetInfoDaoImpl;
import cn.hp.model.City;
import cn.hp.model.Provice;
import cn.hp.model.Street;
import com.alibaba.fastjson.JSONObject;
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 java.io.IOException;
import java.util.List;
@WebServlet("/findstreetdid")
public class FindStreetServlet extends HttpServlet {
public FindStreetServlet() {
super();
}@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
resp.setContentType("text/html;
charset=utf-8");
String id = req.getParameter("id");
StreetInfoDao did = new StreetInfoDaoImpl();
List list=did.findAllStreet(Integer.parseInt(id));
//把这个省份的集合转换成json格式的数据发送到前端页面
resp.getWriter().write(JSONObject.toJSONString(list));
}@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
super.doPost(req, resp);
}}
页面展示代码：
Title - 锐客网
省
市
区DBHelper类：
package cn.hp.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class DBHelper {
private static String Driver = "com.mysql.jdbc.Driver";
private static String Url = "jdbc:mysql://localhost:3306/school?characterEncoding=utf8";
private static String user = "root";
private static String pwd = "root";
public static Connection conn;
// 创建数据库连接
public static Connection getConn() {
try {
Class.forName(Driver);
conn = DriverManager.getConnection(Url, user, pwd);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
} // 关闭数据库连接
public static void getClose() {
try {
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} // 测试数据库连接
public static void main(String[] args) {
System.out.println(getConn());
if (getConn()!=null) {
System.out.println("链接成功");
}
}
}
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