Integration of SpringBoot + MyBatis

First, prepare the environment

• Development Tools: STS
• JDK Version: 1.8
• SpringBoot Version: 2.1.8
• Database: MySQL 8.0.17

Second, the database ready

Database here, but more discussions, you can create a new database as described below

• New Database local
• New data tables user, comprising a primary key id {int}, field name {varchar}, field prosession {varchar}

Third, the project to build

Complete idea of ​​the project to build the following

• 3.1 SpringBoot new project, and add Spring Web, MySQL Driver and MyBatis Framework relies
• 3.2 perfect project directory structure
• 3.3 application.properties configuration database connection configuration file and configuration MyBatis
• 3.4 start the project, demonstrate CRUD

3.1 SpringBoot new project, and add Spring Web, MySQL Driver and MyBatis Framework relies

• New Project

• Project pom.xml file configuration is as follows

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.8.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.mybatis</groupId>
	<artifactId>Mybatis</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>Mybatis</name>
	<description>Spring Boot Mybatis</description>

	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>2.1.0</version>
		</dependency>

		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

3.2 perfect project directory structure

• entity layers: physical layer, the database storing the corresponding entity class
• dao layers: data layer, additions and deletions to achieve entity change search
• Layer service: service level, for the specific operational
• the controller layer: the control layer, the external processing request
• classpath: mapper: store MyBatis mapping file

3.2.1 entity Layer New User class, the corresponding User table in the database

package com.mybatis.entity;

public class User {
	private int id;
	private String name;
	private String profession;

	public User() {

	}

	public User(String name, String profession) {
		this.name = name;
		this.profession = profession;
	}

	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 String getProfession() {
		return profession;
	}

	public void setProfession(String profession) {
		this.profession = profession;
	}
}

3.2.2 dao UserDao new layer interfaces, mapping classpath: mapper / UserMapper.xml file

import java.util.List;

import org.apache.ibatis.annotations.Mapper;

import com.mybatis.entity.User;

@Mapper
public interface UserDao {
	// 新增
	int insert(User user);
	// 删除
	int delete(int id);
	// 修改
	int update(User user);
	// 查询
	List<User> select();
}

3.2.3 service layer UserService new class that implements the business database CRUD

package com.mybatis.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.mybatis.dao.UserDao;
import com.mybatis.entity.User;

@Service
public class UserService {
	
	@Autowired
	private UserDao userDao;
	// 新增业务
	public int insert(User user) {
		return userDao.insert(user);
	}
	// 删除业务
	public int delete(int id) {
		return userDao.delete(id);
	}
	// 修改业务
	public int update(User user) {
		return userDao.update(user);
	}
	// 查询业务
	public List<User> select(){
		return userDao.select();
	}
}

3.2.4 controller added layer UserController class, the processing request

package com.mybatis.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.mybatis.entity.User;
import com.mybatis.service.UserService;

@Controller
public class UserController {
	@Autowired
	private UserService userService;
	
	@ResponseBody
	@RequestMapping("insert")
	public int insert() {
		// 返回新增成功的行数
		return userService.insert(new User("钟力", "Java高级工程师"));
	}
	
	@ResponseBody
	@RequestMapping("delete")
	public int delete() {
		// 返回删除成功的行数
		return userService.delete(1);
	}
	
	@ResponseBody
	@RequestMapping("update")
	public int update() {
		User user = new User("钟力", "Java架构师");
		user.setId(1);
		// 返回修改成功的行数
		return userService.update(user);
	}
	
	@ResponseBody
	@RequestMapping("select")
	public List<User> select() {
		return userService.select();
	}
}

3.2.5 classpath: mapper new UserMapper.xml files, maps, new interfaces dao layer UserDao

<?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.mybatis.dao.UserDao">
	<insert id="insert" parameterType="User">
		insert into user (name, profession) values (#{name}, #{profession})
	</insert>
	<delete id="delete">
		delete from user where id = #{id}
	</delete>
	<update id="update" parameterType="User">
		update user set name = #{name}, profession = #{profession} where id = #{id}
	</update>
	<select id="select" resultType="User">
		SELECT * FROM user
	</select>
</mapper>

3.3 application.properties configuration database connection configuration file and configuration MyBatis

spring.datasource.url=jdbc:mysql://localhost:3306/local?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8&allowPublicKeyRetrieval=true
spring.datasource.username=root
spring.datasource.password=zl0418
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver


mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com.mybatis.entity

3.4 start the project, demonstrate CRUD

3.4.1 New demo - Returns the number of new rows 1, new success

3.4.2 Query demo - just add the data successfully returned, the query was successful

3.4.3 modify the presentation - the number of rows returned 1 changes, modifications success

3.4.4 Delete Demo - Returns the number 1 delete rows, delete success

Four, Github Address

SpringBootMyBatis