JAVA——三级联动 省 市 区
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JAVA 分页效果实现
整体架构为
后端代码
dao层 的接口
省份 的dao的接口
package src.cn.hp.dao;
import src.cn.hp.model.Provice;
import java.util.List;
public interface ProviceInfoDao {
/**
* 查询所有的省份信息
* @return 省份数据
*/
public List<Provice> findAll();
}
市 的dao的接口
package src.cn.hp.dao;
import src.cn.hp.model.City;
import java.util.List;
public interface CityInfoDao {
/**
* 根据省份查询所属的市
* @param pid 省份的id
* @return 省份所属的市
*/
public List<City> findAllCity(int pid);
}
区 的dao的接口
package src.cn.hp.dao;
import src.cn.hp.model.Street;
import java.util.List;
public interface StreetInfoDao {
/**
* 查询 所有区 信息
* @param cid 根据市 的id 查
* @return 区 信息
*/
public List<Street> findAll(int cid);
}
impl层 dao的实现类
省份 dao的实现类 imol
package src.cn.hp.dao.impl;
import src.cn.hp.dao.ProviceInfoDao;
import src.cn.hp.model.Provice;
import src.cn.hp.util.ConnDemo;
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 ProviceInfoDaoImol implements ProviceInfoDao {
@Override
public List<Provice> findAll() {
Connection conn = ConnDemo.getConn();
List<Provice> list = new ArrayList<Provice>();
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;
}
}
市 dao的实现类 imol
package src.cn.hp.dao.impl;
import src.cn.hp.dao.CityInfoDao;
import src.cn.hp.model.City;
import src.cn.hp.model.Provice;
import src.cn.hp.util.ConnDemo;
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<City> findAllCity(int pid) {
Connection conn = ConnDemo.getConn();
List<City> list = new ArrayList<City>();
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 p = new City();
p.setCid(rs.getInt(1));
p.setCname(rs.getString(2));
p.setPid(rs.getInt(3));
list.add(p);
}
} catch (SQLException e) {
e.printStackTrace();
}
return list;
}
}
区 县 dao的实现类 imol
package src.cn.hp.dao.impl;
import src.cn.hp.dao.StreetInfoDao;
import src.cn.hp.model.City;
import src.cn.hp.model.Street;
import src.cn.hp.util.ConnDemo;
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<Street> findAll(int cid) {
Connection conn = ConnDemo.getConn();
List<Street> list = new ArrayList<Street>();
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 p = new Street();
p.setCid(rs.getInt(1));
p.setSname(rs.getString(2));
p.setCid(rs.getInt(3));
list.add(p);
}
} catch (SQLException e) {
e.printStackTrace();
}
return list;
}
}
model层 实体类
省 model
package src.cn.hp.model;
public class Provice {
private int pid;
private String pname;
public Provice(int pid, String pname) {
this.pid = pid;
this.pname = pname;
}
public Provice() {
}
public int getPid() {
return pid;
}
public Provice(String pname) {
this.pname = pname;
}
public void setPid(int pid) {
this.pid = pid;
}
public String getPname() {
return pname;
}
public void setPname(String pname) {
this.pname = pname;
}
}
市 model
package src.cn.hp.model;
public class City {
private int cid;
private String cname;
private int pid;
public City(int cid, String cname, int pid) {
this.cid = cid;
this.cname = cname;
this.pid = pid;
}
public City() {
}
public City(String cname, int pid) {
this.cname = cname;
this.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;
}
}
区 model
package src.cn.hp.model;
public class Street {
private int sid;
private String sname;
private int cid;
public Street(int sid, String sname, int cid) {
this.sid = sid;
this.sname = sname;
this.cid = cid;
}
public int getSid() {
return sid;
}
public void setSid(int sid) {
this.sid = sid;
}
public Street(int cid) {
this.cid = cid;
}
public Street(String sname, int cid) {
this.sname = sname;
this.cid = cid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public int getCid() {
return cid;
}
public void setCid(int cid) {
this.cid = cid;
}
public Street() {
}
}
servlet层
省 servlet
package src.cn.hp.servlet;
import com.alibaba.fastjson.JSONObject;
import src.cn.hp.dao.ProviceInfoDao;
import src.cn.hp.dao.impl.ProviceInfoDaoImol;
import src.cn.hp.model.Provice;
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 {
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
resp.setContentType("text/html;charset=utf-8");
ProviceInfoDao pid = new ProviceInfoDaoImol();
List<Provice> 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));
}
}
市 servlet
package src.cn.hp.servlet;
import com.alibaba.fastjson.JSONObject;
import src.cn.hp.dao.CityInfoDao;
import src.cn.hp.dao.ProviceInfoDao;
import src.cn.hp.dao.impl.CityInfoDaoImpl;
import src.cn.hp.dao.impl.ProviceInfoDaoImol;
import src.cn.hp.model.City;
import src.cn.hp.model.Provice;
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("/findcitybypid")
public class FindCityByPidServlet extends HttpServlet {
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 pid = new CityInfoDaoImpl();
List<City> list = pid.findAllCity(Integer.parseInt(id));
// 把这个城市的集合转换成json 格式的数据发送到前端页面
resp.getWriter().write(JSONObject.toJSONString(list));
}
}
区 servlet
package src.cn.hp.servlet;
import com.alibaba.fastjson.JSONObject;
import src.cn.hp.dao.CityInfoDao;
import src.cn.hp.dao.StreetInfoDao;
import src.cn.hp.dao.impl.CityInfoDaoImpl;
import src.cn.hp.dao.impl.StreetInfoDaoImpl;
import src.cn.hp.model.City;
import src.cn.hp.model.Street;
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("/findstreetbypid")
public class FindStreetByPidServlet extends HttpServlet {
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 pid = new StreetInfoDaoImpl();
List<Street> list = pid.findAll(Integer.parseInt(id));
// 把这个城市的集合转换成json 格式的数据发送到前端页面
resp.getWriter().write(JSONObject.toJSONString(list));
}
}
util 层 工具类
package src.cn.hp.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class ConnDemo {
private static String Driver = "com.mysql.jdbc.Driver";
private static String Url = "jdbc:mysql://localhost:3306/provices?characterEncoding=utf8";
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