Get the list of provinces and cities 【 project mall 】

Get the list of provinces and cities

1 Get the list of provinces and cities – database

create table `t_dict_district` (
	`id` int (11) NOT NULL AUTO_INCREMENT,
	`parent` varchar (6) DEFAULT NULL,
	`code` varchar (6) DEFAULT NULL,
	`name` varchar (16) DEFAULT NULL,
     PRIMARY KEY (`id`)
);
insert into `t_dict_district` (`id`, `parent`, `code`, `name`) values('1','110100','110101',' Dongcheng District ');
insert into `t_dict_district` (`id`, `parent`, `code`, `name`) values('2','110100','110102',' Xicheng district ');
insert into `t_dict_district` (`id`, `parent`, `code`, `name`) values('3','110100','110103',' Chongwen District ');
insert into `t_dict_district` (`id`, `parent`, `code`, `name`) values('4','110100','110104',' Xuanwu District ');
insert into `t_dict_district` (`id`, `parent`, `code`, `name`) values('5','110100','110105',' Chaoyang District ');

parent Property represents the code number of the parent region , The parent code number of the province +86.
t_dict_district.sql

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2 Get the list of provinces and cities - Entity class

Create a District Entity class .

package com.cy.store.entity;

import java.io.Serializable;
import java.util.Objects;

/**  province / City / Entity class of area data  */
public class District implements Serializable {
    
    private Integer id;
    private String parent;
    private String code;
    private String name;

District

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3 Get the list of provinces and cities - Persistence layer

Query statement , Query according to the parent code .

select * from t_dict_district where parent =? order by code ASC

Abstract method definition .
DistrictMapper

package com.cy.store.mapper;

import com.cy.store.entity.District;

import java.util.List;

public class DistrictMapper {
    
    /** *  Query information according to parent code  * @param parent  Parent code  * @return  List of all areas under a parent area  */
    List<District> findByParent(Integer parent);
}

DistrictMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cy.store.mapper.DistrictMapper">
    <!--  Access to all provinces in the country / All cities in a province / All districts of a city ：List<District> findByParent(String parent) -->
    <select id="findByParent" resultType="com.cy.store.entity.District">
        SELECT * FROM t_dict_district WHERE parent=#{
    parent} ORDER BY code ASC
    </select>
</mapper>

DistrictMapper–findByParent

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test

 @Autowired
    private DistrictMapper districtMapper;

    @Test
    public void findByParent(){
    
        List<District> list = districtMapper.findByParent("110100");
        for (District d:list) {
    
            System.out.println(d);
        }

    }

master → origin/master

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4 Get the list of provinces and cities - The business layer

1. Create an interface IDistrictService, And define abstract methods .

package com.cy.store.service;

import com.cy.store.entity.District;

import java.util.List;

public interface IDistrictService {
    
    /** *  Query the information of the area according to the parent code ( Provincial city ) * @param parent  Parent code  * @return  Multiple area information  */
    List<District> getParent(String parent);
}

2. establish DistrictServiceImpl Implementation class , Implement abstract methods .

package com.cy.store.service.impl;

import com.cy.store.entity.District;
import com.cy.store.mapper.DistrictMapper;
import com.cy.store.service.IDistrictService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class DistrictServiceImpl implements IDistrictService {
    

    @Autowired
    private DistrictMapper districtMapper;

    @Override
    public List<District> getParent(String parent) {
    
        List<District> list = districtMapper.findByParent(parent);
        /** *  During network data transmission , In order to avoid invalid data transmission , Invalid data can be set to null *  Can save traffic , On the other hand, it improves efficiency  */
        for (District d:list) {
    
            d.setId(null);
            d.setParent(null);
        }
        return list;
    }
}

DistrictService–getParent

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test

package com.cy.store.service;

import com.cy.store.entity.Address;
import com.cy.store.entity.District;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.yaml.snakeyaml.events.Event;

import java.util.List;

//@SpringBootTest： Indicates that the current class is a test class , Will not be packaged with the project 
@SpringBootTest
//@RunWith： Means to start this unit test class （ Unit test classes cannot be run ）, You need to pass a parameter , Must be SpringRunner The instance type of 
//@RunWith(SpringRunner.class)
public class DistrictServiceTests {
    

    @Autowired
    private IDistrictService districtService;


    @Test
    public void getParent(){
    
        List<District> list = districtService.getParent("86");
        for (District d : list) {
    
            System.err.println(d);
        }
    }


}

DistrictServiceTests–getParent

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5 Get the list of provinces and cities - Control layer

5.1 Design request

/districts/
GET 
String parent
JsonResult<List<District>>

5.2 Write a request

Create a class DistrictController class , Write a method to process the request in the class .

package com.cy.store.controller;

import com.cy.store.entity.District;
import com.cy.store.service.IDistrictService;
import com.cy.store.util.JsonResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("districts")
public class DistrictController extends BaseController {
    
    @Autowired
    private IDistrictService districtService;
    
    // Anyone who districts The first requests are intercepted getByParent() Method 
    @RequestMapping({
    "/",""})
    public JsonResult<List<District>> getByParent(String parent){
    
        List<District> data = districtService.getParent(parent);
        return new JsonResult<>(OK,data);
    }
}

LoginInterceptorConfigurer–districts

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districts Request to be added to the white list

patterns.add("/districts/**");

test

Direct request server , To access and test
http://localhost:8080/districts?parent=86

http://localhost:8080/districts?parent=610000

6 Get the list of provinces and cities - Front page

addAddress.html
1. Comment out through js To complete the list of provinces and cities js Code

<!--		<script type="text/javascript" src="../js/distpicker.data.js"></script>-->
<!--		<script type="text/javascript" src="../js/distpicker.js"></script>-->

2. Check whether the front page is relevant when submitting the list data of provinces and cities name Properties and id attribute .
3. Run the front end to see if the data can be saved normally （ Except for the provincial and urban areas ）.

addAddress–js

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test

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