Spring Boot集成MyBatis实战：数据库连接与用户查询-优快云博客

一、准备

1、导入相关jar包

<dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.0.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.0.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.2</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
        </dependency>
		
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
        </dependency>
        
    </dependencies>

2、数据库
在这里插入图片描述

3、UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.massimo.mapper.UserMapper">

    <select id="selectUser" resultType="users">
        select * from users;
    </select>

</mapper>

4、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核心配置文件-->
<configuration>
    <typeAliases>
        <package name="com.massimo.pojo"/>
    </typeAliases>

</configuration>

5、实体类

package com.massimo.pojo;

import lombok.Data;

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

6、接口

package com.massimo.mapper;

import com.massimo.pojo.Users;

import java.util.List;

public interface UserMapper {
    public List<Users> selectUser();
}

二、整合

2.1、spring-dao.xml配置文件

编写数据源配置 + sqlSessionFactory + sqlSessionTemplate + 将自己写的实现类，注入到Spring中

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd">

        <!-- DataSource:使用Spring的数据源替换Mybatis配置  c3p0  dbcp  druid
        这里使用Spring提供的JDBC：org.springframework.jdbc.datasource
        -->
        <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
            <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
            <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
            <property name="username" value="root"/>
            <property name="password" value="123456"/>
        </bean>

        <!--sqlSessionFactory-->
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            <property name="dataSource" ref="dataSource"/>
            <!--绑定Mybatis配置文件-->
            <property name="configLocation" value="classpath:mybatis-config.xml"/>
            <property name="mapperLocations" value="classpath:com/massimo/mapper/*.xml"/>
        </bean>

        <!--SqlSessionTemplate:就是我们使用的sqlSession-->
        <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
                <!--只能使用构造器注入sqlSessionFactory，因为它没有set方法-->
                <constructor-arg index="0" ref="sqlSessionFactory"/>
        </bean>

        <!-- -->
        <bean id="userMapper" class="com.massimo.mapper.UserMapperImpl">
            <property name="sqlSession" ref="sqlSession"/>
        </bean>
</beans>

2.2、给接口加实现类

package com.massimo.mapper;

import com.massimo.pojo.Users;
import org.mybatis.spring.SqlSessionTemplate;

import java.util.List;

public class UserMapperImpl implements UserMapper {

    //我们所有的操作，在原来，都使用sqlSession来执行，现在都使用SqlSessionTemplate；
    private SqlSessionTemplate sqlSession;

    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

    public List<Users> selectUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

2.3、测试

import com.massimo.mapper.UserMapper;
import com.massimo.pojo.Users;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

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

public class MyTest {

    @Test
    public void test() throws IOException {
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
        UserMapper mapper = context.getBean("userMapper", UserMapper.class);
        for (Users users : mapper.selectUser()) {
            System.out.println(users);
        }
    }
}