springboot整合mybatis

 

 导入依赖：

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <!--整合  druid数据源 mybatis MysqL junit-↑ jdbc-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.3</version>
        </dependency>

        <dependency>
            <groupId>MysqL</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.1</version>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>


        <!--引入thymeleaf依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
    </dependencies>

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

        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>

写一下UserMapper.interface

/*
* 从mybatis3.4.0开始加入了@Mapper注解，目的就是为了不再写mapper映射文件（那个xml写的是真的蛋疼。。。）。
* @Mapper 是mybatis的注解  @Repository让spring容器帮我们自动装配bean
* */
@Mapper
@Repository
public interface UserMapper {
    //查询
    public List<User> queryAll();
    //添加数据
    public int addUser(User user);
    //根据用户名模糊查询
    public List<User> queryByLikeName(String username);
}

写一下UserMapper.xml

<mapper namespace="com.example.demo.mapper.UserMapper">

    <select id="queryAll" resultType="com.example.demo.pojo.User">
        select * from user
    </select>

    <insert id="addUser" parameterType="com.example.demo.pojo.User">
        insert into user (username,userid)
        values (#{username},${userid});
    </insert>

    <select id="queryByLikeName" parameterType="String" resultType="com.example.demo.pojo.User">
        select * from user where username like #{arg0}
    </select>

</mapper>

在主启动类头上写mapper扫描注解

//去扫描mapper
@MapperScan("com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {

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

 测试一下

@SpringBoottest
class DemoApplicationTests {

    @Autowired
    DataSource dataSource;

    @Autowired
    UserMapper userMapper;

    @Test
    void contextLoads() {
        System.out.println(dataSource.getClass()); //查看现在所使用的数据源
        final List<User> users = userMapper.queryAll();
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    void contextLoads2() {
        final List<User> users = userMapper.queryByLikeName("%用%");
        for (User user : users) {
            System.out.println(user);
        }
    }

}