[JAVA] [Practice! ] Minimum settings when using MyBatis

1. Prior knowledge

-[Even beginners can do it! ] How to install Eclipse on Windows 10 (Java environment construction) -[Practice! ] Display Hello World with Spring Boot -[Practice! ] Java database linkage (Connector / J 8.0.20)

As prior knowledge, the contents of the above link are required.

2. Preparation

Type cmd in the search box to launch Command Prompt.
Login with mysql -u username -p.

`test.sql`


create database test DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;

use test;

CREATE TABLE test1( 
    id TINYINT ZEROFILL NOT NULL AUTO_INCREMENT,
    name VARCHAR(50),
    PRIMARY KEY(id));

INSERT INTO `test1`(`name`) VALUES ("test1");
INSERT INTO `test1`(`name`) VALUES ("test2");
INSERT INTO `test1`(`name`) VALUES ("test3");
INSERT INTO `test1`(`name`) VALUES ("test4");

Copy the above SQL statement and execute it in the command prompt.
Success if Query OK appears as shown in the image.

3. Create Spring Boot project

Select [File (F)]-> [New (N)]-> [Spring Starter Project].
Enter MyBatisTest as the name, select Java version: 8 and click the Next> button.
Select Spring Boot Version: 2.3.1, Lombok, JDBC API, MyBatis Framework, MySQL Driver, Thymeleaf, Spring Web and click the Done button. ..

4. Run the Spring Boot project

`Folder structure`


MyBatisTest
└─ src
     └─ main
          ├─ java
          │   └─ com
          │        └─ example
          │             └─ demo
          │                  ├─ Entity.java
          │                  └─ TestController.java
          └─ resources
               ├─ application.properties
               ├─ mybatis-config.xml
               ├─ sample_mapper.xml
               │  
               ├─ static
               └─ templates
                    └─ index.html

`Entity.java`


package com.example.demo;

import lombok.Data;

@Data
public class Entity {
	private int id;
	private String name;
}

`TestController.java`


package com.example.demo;

import java.io.InputStream;
import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class TestController {
    //Read the root configuration file
	InputStream in = TestController.class.getResourceAsStream("/mybatis-config.xml");

	//Create SqlSessionFactory based on configuration file
	SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);

	//Generate SqlSession from SqlSessionFactory
	SqlSession session = factory.openSession();

    @GetMapping("/")
    public String index(Model model) {

    	//Execute SQL using SqlSession
    	List<Entity> result = session.selectList("sample.mybatis.selectTest");

        model.addAttribute("Test", result);
        return "index";
    }
}

`application.properties`


spring.datasource.url=jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8&serverTimezone=JST
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto = update

`mybatis-config.xml`


<?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="sample_id">
    <environment id="sample_id">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost/test?serverTimezone=JST"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="sample_mapper.xml"/>
  </mappers>
</configuration>

`sample_mapper.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="sample.mybatis">
  <select id="selectTest" resultType="com.example.demo.Entity">
    select * from test1
  </select>
</mapper>

`index.html`


<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org/">
  <head>
    <title>Test</title>
    <meta charset="utf-8" />
  </head>
  <body>
    <ul>
      <li th:each="entity : ${Test}">
        [[${entity.getId()}]]
        [[${entity.getName()}]]
      </li>
    </ul>
  </body>
</html>

Arrange the files as shown in the folder structure above, right-click MyBatisTest [boot] and select [Run] → [5 Maven install].

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  4.125 s
[INFO] Finished at: 2020-07-05T21:50:22+09:00
[INFO] ------------------------------------------------------------------------

Success if the above statement is displayed on the console.
Right-click on MyBatisTest [boot] and select [Run] → [9 Spring Boot Application].
Access [localhost: 8080](http: // localhost: 8080 /), and if it looks like the image, it is successful.

[JAVA] [Practice! ] Minimum settings when using MyBatis

1. Prior knowledge

2. Preparation

test.sql

3. Create Spring Boot project

4. Run the Spring Boot project

Folder structure

Entity.java

TestController.java

application.properties

mybatis-config.xml

sample_mapper.xml

index.html

5. Related

`test.sql`

`Folder structure`

`Entity.java`

`TestController.java`

`application.properties`

`mybatis-config.xml`

`sample_mapper.xml`

`index.html`