Maven Dependency

Add the following dependency to your pom.xml file:

<dependency>
    <groupId>tk.mybatis</groupId>
    <artifactId>mapper-spring-boot-starter</artifactId>
    <version>2.1.5</version>
</dependency>

Defining Mapper Interfaces

Create mapper interfaces in your DAO layer that extend tk.mybatis.mapper.common.Mapper. The generic type parameter represents your entity class.

package com.example.tkmybatis.mapper;

import com.example.tkmybatis.entity.Department;
import tk.mybatis.mapper.common.Mapper;

public interface DepartmentMapper extends Mapper<Department> {
}

Configuring Mapper Scanning

Add the @MapperScan annotation to your main application class to enable Spring to discover your mapper interfaces:

package com.example.tkmybatis;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication
@MapperScan("com.example.tkmybatis.mapper")
public class TkMybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(TkMybatisApplication.class, args);
    }
}

DataSource Configuration

Configure your database connection in application.yml:

server:
  servlet:
    context-path: /mapper
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=Asia/Shanghai
    username: root
    password:
logging:
  level:
    org.example: debug

Entity Class Definition

Define your entity using JPA annotations for mapping to database tables:

import javax.persistence.Table;
import lombok.Data;

/**
 * Mapping entity to database table using JPA conventions
 */
@Data
@Table(name = "t_user")
public class User {
    @Id
    @Column(name = "user_id")
    private Integer userId;
    
    @Column(name = "user_name")
    private String userName;
    
    @Column(name = "password")
    private String password;
}

Writing Test Cases

Create integration tests to verify mapper functionality:

package com.example.tkmybatis;

import com.example.tkmybatis.entity.User;
import com.example.tkmybatis.mapper.UserMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
public class UserMapperTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void findOne() {
        User user = userMapper.selectByPrimaryKey(1);
        System.out.println(user);
    }
}

Automatic Code Generation

Project Strucutre

Maven Plugin Configuration

Add the MyBatis Generator plugin to your pom.xml:

<plugin>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-maven-plugin</artifactId>
    <version>1.3.6</version>
    <configuration>
        <configurationFile>
            ${basedir}/src/main/resources/generator/generatorConfig.xml
        </configurationFile>
        <overwrite>true</overwrite>
        <verbose>true</verbose>
    </configuration>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.25</version>
        </dependency>
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper</artifactId>
            <version>4.0.0</version>
        </dependency>
    </dependencies>
</plugin>

Generator Configuration Files

Create two configuration files in src/main/resources/generator/: config.properties and generatorConfig.xml.

config.properties:

jdbc.driverClass=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?nullCatalogMeansCurrent=true&serverTimezone=GMT%2b8
jdbc.user=root
jdbc.password=
moduleName=dept
tableName=t_dept

generatorConfig.xml:

<generatorConfiguration>
    <properties resource="generator/config.properties"/>
    <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat">
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>

        <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
            <property name="mappers" value="tk.mybatis.mapper.common.Mapper"/>
            <property name="caseSensitive" value="true"/>
            <property name="lombok" value="Getter,Setter,ToString"/>
        </plugin>
        <jdbcConnection driverClass="${jdbc.driverClass}"
                        connectionURL="${jdbc.url}"
                        userId="${jdbc.user}"
                        password="${jdbc.password}">
        </jdbcConnection>
        <javaModelGenerator targetPackage="com.example.tkmybatis.entity.${moduleName}"
                            targetProject="src/main/java"/>
        <sqlMapGenerator targetPackage="com.example.tkmybatis.mapper.${moduleName}"
                         targetProject="src/main/java"/>
        <javaClientGenerator targetPackage="com.example.tkmybatis.mapper.${moduleName}"
                             targetProject="src/main/java"
                             type="XMLMAPPER"/>
        <table tableName="${tableName}">
            <generatedKey column="id" sqlStatement="JDBC"/>
            <domainObjectRenamingRule searchString="^T" replaceString=""/>
        </table>
    </context>
</generatorConfiguration>

Running the Generator

Execute the code generator through Maven:

1. Open the Maven tool window in your IDE
2. Locate the newly added plugin configuration
3. Double-click the mybatis-generator:generate goal

This generates the mapper interfaces, XML mapping files, and entity classes for the configured table.