190_整合MyBatis

目录

• 整合MyBatis
  • 创建项目
  • 添加mybatis依赖
  • 配置数据库连接信息application.yml
  • 测试
  • 添加lombok依赖
  • 创建实体类
  • 创建Mapper接口
  • 或者在主入口添加注解@MapperScan("com.qing.mapper")，添加后Mapper接口可以不加注解@Mapper
  • 配置别名和Mapper.xml地址application.yml
  • 创建mybatis.mapper目录及Mapper.xml
  • 创建Controller
  • 测试
  • 可以再整合Druid

整合MyBatis

创建项目

添加mybatis依赖

<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.0</version>
</dependency>

<?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>2.6.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.qing</groupId>
    <artifactId>springboot-05-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-05-mybatis</name>
    <description>springboot-05-mybatis</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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>

配置数据库连接信息application.yml

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8
    driver-class-name: com.mysql.cj.jdbc.Driver

测试

package com.qing;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootTest
class Springboot05MybatisApplicationTests {

    @Autowired
    DataSource dataSource;

    @Test
    void contextLoads() throws SQLException {
        System.out.println(dataSource.getClass());
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

}

添加lombok依赖

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

创建实体类

package com.qing.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    private String name;
    private String pwd;
}

创建Mapper接口

package com.qing.mapper;

import com.qing.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper // @Mapper 表示这个接口是MyBatis的Mapper类
@Repository
public interface UserMapper {

    List<User> list();
}

或者在主入口添加注解@MapperScan("com.qing.mapper")，添加后Mapper接口可以不加注解@Mapper

package com.qing;

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

@SpringBootApplication
// @MapperScan("com.qing.mapper")
public class Springboot05MybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(Springboot05MybatisApplication.class, args);
    }

}

配置别名和Mapper.xml地址application.yml

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8
    driver-class-name: com.mysql.cj.jdbc.Driver

# mybatis
mybatis:
  type-aliases-package: com.qing.pojo
  mapper-locations: classpath:mybatis/mapper/*.xml

创建mybatis.mapper目录及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="com.qing.mapper.UserMapper">
    <select id="list" resultType="User">
        select * from user
    </select>
</mapper>

创建Controller

package com.qing.controller;

import com.qing.mapper.UserMapper;
import com.qing.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {
    @Autowired
    private UserMapper userMapper;

    @RequestMapping("/user/list")
    public List<User> list() {
        return userMapper.list();
    }
}

测试

可以再整合Druid