Integrating MyBatis with Spring Boot Applications
Database Schema Setup
Create the user table with the following SQL definition:
CREATE TABLE `tb_user` (
`id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'Primary Key',
`username` varchar(50) NOT NULL COMMENT 'User Name',
`age` int(11) NOT NULL COMMENT 'User Age',
`ctm` datetime NOT NULL COMMENT 'Creation Timestamp',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `tb_user` (`username`, `age`, `ctm`) VALUES
('John Doe', '25', NOW()),
('Jane Smith', '30', NOW());
Maven Dependencies Configuration
Configure the project's pom.xml with required dependencies:
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>spring-mybatis-integration</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.0</version>
</parent>
<dependencies>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.2.2</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.33</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Application Properties Configuration
Define database connection and MyBatis settings in application.yml:
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/user_database
username: admin
password: secret123
mybatis:
mapper-locations: classpath:mapping/*.xml
config-location: classpath:mybatis-config.xml
type-aliases-package: com.example.model
MyBatis XML Mapping File
Create UserRepository.xml for SQL operations:
<?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.example.repository.UserRepository">
<resultMap id="UserMap" type="com.example.model.UserEntity">
<id column="id" property="identifier" jdbcType="INTEGER" />
<result column="username" property="name" jdbcType="VARCHAR" />
<result column="age" property="userAge" jdbcType="INTEGER" />
<result column="ctm" property="createdTime" jdbcType="TIMESTAMP" />
</resultMap>
<sql id="columns">id, username, age, ctm</sql>
<select id="findAllUsers" resultMap="UserMap">
SELECT <include refid="columns" /> FROM tb_user
</select>
<select id="findUserById" parameterType="int" resultMap="UserMap">
SELECT <include refid="columns" /> FROM tb_user WHERE id = #{userId}
</select>
<insert id="createUser" parameterType="com.example.model.UserEntity">
INSERT INTO tb_user (username, age, ctm)
VALUES (#{name}, #{userAge}, NOW())
</insert>
<update id="modifyUser" parameterType="map">
UPDATE tb_user
SET username = #{userData.name}, age = #{userData.userAge}
WHERE id = #{identifier}
</update>
<delete id="removeUser" parameterType="int">
DELETE FROM tb_user WHERE id = #{userId}
</delete>
</mapper>
MyBatis Configuration File
Basic mybatis-config.xml setup:
<?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>
<settings>
<setting name="mapUnderscoreToCamelCase" value="true" />
</settings>
<typeAliases>
<package name="com.example.model" />
</typeAliases>
</configuration>
Data Model Class
Define the entity class in UserEntity.java:
package com.example.model;
import java.util.Date;
public class UserEntity {
private Integer identifier;
private String name;
private Integer userAge;
private Date createdTime;
// Constructors
public UserEntity() {}
public UserEntity(String name, Integer userAge) {
this.name = name;
this.userAge = userAge;
}
// Getters and Setters
public Integer getIdentifier() { return identifier; }
public void setIdentifier(Integer identifier) { this.identifier = identifier; }
public String getName() { return name; }
public void setName(String name) { this.name = name; }
public Integer getUserAge() { return userAge; }
public void setUserAge(Integer userAge) { this.userAge = userAge; }
public Date getCreatedTime() { return createdTime; }
public void setCreatedTime(Date createdTime) { this.createdTime = createdTime; }
}
Repository Interface
Create the data access interface:
package com.example.repository;
import java.util.List;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;
import com.example.model.UserEntity;
@Repository
public interface UserRepository {
UserEntity findUserById(Integer userId);
List<UserEntity> findAllUsers();
int createUser(UserEntity user);
int modifyUser(@Param("identifier") Integer id, @Param("userData") UserEntity user);
int removeUser(Integer userId);
}
Service Layer Implementation
Business logic service interfaces and implementation:
package com.example.service;
import java.util.List;
import com.example.model.UserEntity;
public interface UserManagementService {
UserEntity retrieveUser(Integer id);
List<UserEntity> getAllUsers();
boolean registerUser(UserEntity user);
boolean updateUserProfile(Integer id, UserEntity user);
boolean deleteUserAccount(Integer id);
}
package com.example.service.impl;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.example.model.UserEntity;
import com.example.repository.UserRepository;
import com.example.service.UserManagementService;
@Service
public class UserManagementServiceImpl implements UserManagementService {
@Autowired
private UserRepository userRepository;
@Override
public UserEntity retrieveUser(Integer id) {
return userRepository.findUserById(id);
}
@Override
public List<UserEntity> getAllUsers() {
return userRepository.findAllUsers();
}
@Override
public boolean registerUser(UserEntity user) {
return userRepository.createUser(user) > 0;
}
@Override
public boolean updateUserProfile(Integer id, UserEntity user) {
return userRepository.modifyUser(id, user) > 0;
}
@Override
public boolean deleteUserAccount(Integer id) {
return userRepository.removeUser(id) > 0;
}
}
REST Controller
Web layer for handling HTTP requsets:
package com.example.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import com.example.model.UserEntity;
import com.example.service.UserManagementService;
import com.example.util.ApiResponse;
@RestController
@RequestMapping("/api/users")
public class UserRestController {
@Autowired
private UserManagementService userService;
@GetMapping("/{userId}")
public ResponseEntity<ApiResponse> getUser(@PathVariable Integer userId) {
ApiResponse response = new ApiResponse();
try {
UserEntity user = userService.retrieveUser(userId);
response.setData(user);
response.setMessage("Success");
return ResponseEntity.ok(response);
} catch (Exception ex) {
response.setError(ex.getMessage());
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(response);
}
}
}
Response Utility Class
Standard API response wrapper:
package com.example.util;
public class ApiResponse {
private String message;
private Object data;
private String error;
public String getMessage() { return message; }
public void setMessage(String message) { this.message = message; }
public Object getData() { return data; }
public void setData(Object data) { this.data = data; }
public String getError() { return error; }
public void setError(String error) { this.error = error; }
}
Application Bootstrap Class
Main application entry point:
package com.example;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.repository")
public class ApplicationBootstrap {
public static void main(String[] args) {
SpringApplication.run(ApplicationBootstrap.class, args);
}
}
