地区选择数据库形式的基础数据转成JSON串

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　　在做H5开发过程中，地区选择的基础数据产品经理不知从哪里哪来了一些SQL，而这个数据其实很难会变，存储在后台的DB或者缓存中，好像没有必要，于是得想办法把它转成json串保存到文件中，请求时直接请求这个JSON串文件即可。

基础SQL：

DROP TABLE IF EXISTS Province;
DROP TABLE IF EXISTS City;
DROP TABLE IF EXISTS District;

CREATE TABLE Province (Id int,
	Name varchar(50) ,
	orderid int 
)row_format=dynamic engine=innodb default charset utf8;
insert into Province values('1','北京','0'); 
insert into Province values('2','天津','0');

CREATE TABLE City(
	Id int ,
	ProvinceId int,
	Name varchar(50),
	AreaCode varchar(50)
)row_format=dynamic engine=innodb default charset utf8;

insert into City values('1','1','北京市','010'); 
insert into City values('2','2','天津市','022'); 
insert into City values('3','3','石家庄市','0311'); 
insert into City values('4','3','唐山市','0315'); 

CREATE TABLE District(
	Id int ,
	CityId int ,
	Name varchar(50),
	PostCode varchar(50)
)row_format=dynamic engine=innodb default charset utf8;

insert into District values('1','1','东城区','100010'); 
insert into District values('2','1','西城区','100032'); 
insert into District values('3','1','崇文区','100061'); 
insert into District values('4','1','宣武区','100054'); 
insert into District values('5','1','朝阳区','100020'); 
insert into District values('6','1','丰台区','100071'); 
insert into District values('7','1','石景山区','100043'); 

　　一看，乖乖，这不就是一对多的关系吗？于是想到用MyBatis处理即可。参考myBatis系列之四：关联数据的查询和【Mybatis高级映射】一对一映射、一对多映射、多对多映射很快就写出来了。

Configuration.xml

log4j2.xml

ProvinceMapper.java

package com.bijian.study.dao;

import java.util.List;

import com.bijian.study.dto.Province;

public interface ProvinceMapper {
    
    Province getProvinceById(int id);
    List getProvinceList();
    
    List getAllProvinceList();
}

Province.java

package com.bijian.study.dto;

import java.util.List;

public class Province {

    private int id;
    private String name;
    private int orderid;
    private List subs;
    
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getOrderid() {
        return orderid;
    }
    public void setOrderid(int orderid) {
        this.orderid = orderid;
    }
    public List getSubs() {
      return subs;
    }
    public void setSubs(List subs) {
      this.subs = subs;
    }
}

Province.xml

  


	
	
		
		
		
	

	
		select * from Province where Id = #{id}
	

	
		select * from Province
	
	
	
		
		
		
		
			
			
			
			
			
			
				
				
				
					
			
		
	

	
		select p.Id p_id, p.Name p_name, c.Id c_id, c.ProvinceId c_provinceId, c.Name c_name, c.AreaCode c_areaCode, d.Id d_id, d.CityId d_cityId, d.Name d_name, d.PostCode d_postCode
		from Province p inner join City c on p.Id=c.ProvinceId
		inner join District d on c.Id=d.CityId
	

Main.java

package com.bijian.study;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.bijian.study.dao.ProvinceMapper;
import com.bijian.study.dto.Province;
import com.fasterxml.jackson.databind.ObjectMapper;

public class Main {
    
    private static final Logger log = LoggerFactory.getLogger(Main.class);  
    private static SqlSessionFactory sqlSessionFactory;  
  
    private static Reader reader;
    
    public static void main(String[] args) {
        try {
            reader = Resources.getResourceAsReader("Configuration.xml");  
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
            
            SqlSession session = sqlSessionFactory.openSession();
            
            ProvinceMapper mapper = session.getMapper(ProvinceMapper.class);  
            List provinceList = mapper.getAllProvinceList();
            log.info("{}", provinceList.size());
            
            ObjectMapper objMapper = new ObjectMapper();
            String provinceListStr = objMapper.writeValueAsString(provinceList);
            
            log.info("{}", provinceListStr);
        } catch (IOException e) {  
            log.error("Error thrown while reading the configuration: {}", e);  
        } finally {  
            if (reader != null) {  
                try {  
                    reader.close();  
                } catch (IOException e) {  
                    log.error("Error thrown while closing the reader: {}", e);  
                }  
            }  
        }  
    }
}

运行Main.java，结果如下：

　　当然，由于在实际应用中，根本无需id、cityId等，postCode、areaCode也统一用code，所以修改一下对应的sqlMapper及dto，详见附件工程包《JsonTransfer.rar》，运行Main2.java结果如下所示：

• 
• 大小: 20.6 KB

• 
• 大小: 22.2 KB

• JsonTransfer.rar (5.1 MB)
• 下载次数: 1

• 查看图片附件