mybatis Study Notes (1) Basic environment

    1.pom introduced

    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.1</version>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.17</version>
        </dependency>
    </dependencies>

　　2. config configuration. Add mybatis-config.xml in resource

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <!-- 配置数据库连接信息 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value=""/>
                <property name="username" value=""/>
                <property name="password" value=""/>
            </dataSource>
        </ Environment> 
    </environments>
    <by mappers> 
        <-! add a mapping file Mybatis global configuration file -> 
        <Resource Mapper = "Learn / MyBatis / CarrierMapper.xml" /> 
    </ by mappers> 
</ Configuration>

　　3. Add the development needs of the mapper, entity classes

CarrierMapper.xml

<? xml Version = "1.0" encoding = "UTF-8"?> 
<DOCTYPE Mapper the PUBLIC! "- // mybatis.org//DTD Mapper 3.0 // EN" "http://mybatis.org/dtd/mybatis mapper.dtd--3 "> 
<-! 
namespace: namespace 
id: uniquely identifies 
resultType: return value type 
# {id}: id taken from the parameter values passed over the 
 -> 
<Mapper namespace =" learn.mybatis .CarrierMapper "> 
    <SELECT ID =" queryAll "the resultType =" learn.mybatis.Carrier "> 
        SELECT ID, carrier_no carrierNo, CARRIER_NAME CarrierName, main_page MainPage from t_carrier WHERE IS_DELETED = 0 
    </ SELECT> 
</ Mapper>

　　CarrierMapper.java

package learn.mybatis;

import java.util.List;

/**
 * Create by tianqing on 2019/7/24.
 */
public interface CarrierMapper {
    List<Carrier>  queryAll();
}

　　

Carrier.java

public class Carrier {
    private Long id;

    private String carrierNo;

    private String carrierName;

    private String mainPage;

    /**
     * 承运商类型
     */
    private Integer carrierType;

    private Integer isDeleted;

    private String creator;

    private String editor;

    private Date createTime;

    private Date editTime;
    
    getset...
}

　　4. The overall directory structure

5. Run the main method.

package learn.mybatis;

import com.google.gson.Gson;
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 java.io.InputStream;
import java.util.List;

/**
 * Create by tianqing on 2019/7/23.
 */
public class MybatisLearn {
    private static final Logger logger = LoggerFactory.getLogger(MybatisLearn.class);

    public static void main(String[] args) throws Exception {
        //前三步都相同
        InputStream = Resources.getResourceAsStream InputStream ( "the mybatis-config.xml"); 
        SqlSessionFactory Factory's new new the SqlSessionFactoryBuilder = () Build (inputStream);. 
        SqlSession SQLSESSION = factory.openSession (); 
        // this is no longer calls the SqlSession api, but get the interface object, interface method calls. 
        Mapper = sqlSession.getMapper CarrierMapper (CarrierMapper.class); 
        List <Carrier> Carriers mapper.queryAll = (); 
        Gson GSON new new Gson = (); 
        logger.info ( "[MybatisLearn - main] Results: {}", gson. the toJson (Carriers)); 

    } 
}

　　6. Execute and print.

 

Run up later. We do not worry multiple uses, mybatis how to achieve the next chapter of research at approximately