SpringBoot2.0之四 简单整合MyBatis

  从最开始的SSH（Struts+Spring+Hibernate）,到后来的SMM（SpringMVC+Spring+MyBatis），到目前的S（SpringBoot）,随着框架的不断更新换代，也为我们广大的程序猿提供了更多的方便，一起搭建一个从控制层到持久层的项目可能需要一两天的时间，但是采用SpringBoot的方式，我们可能只需要10分钟就能轻松完成一个web项目的搭建，下面我们介绍一下SpringBoot2.0整合MyBatis的方法

一、新建一个项目，引入相关依赖

   <!-- 单元测试依赖 start -->
  	<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-test</artifactId>
	</dependency>
    <!-- 单元测试依赖 end -->
    
    <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>1.3.1</version>
   </dependency>
    
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>

二、新建一个实体类

public class User {

	private Long id;
	
	private String name;//姓名
	
	private Integer age;//年龄
	//。。。

}

三、新建一个Dao层

public interface UserDao {

	int addUser(User user);
	
	int deleteUserById(Long id);
	
	int updateUserById(User user);

	User queryUserById(Long id);
	
	List<User> queryUserList();
}

四、新建MyBatis的sql操作文件

<?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.somta.springboot.dao.UserDao" > 
<!-- Result Map-->
<resultMap id="BaseResultMap" type="com.somta.springboot.pojo.User" >
	<result column="id" property="id"/>
	<result column="name" property="name"/>
	<result column="age" property="age"/>
</resultMap>
       
<!-- th_role_user table all fields -->
<sql id="Base_Column_List" >
	id, name, age
</sql>
   
<insert id="addUser" parameterType="com.somta.springboot.pojo.User" >
	insert into t_user (id, name, age) 
	values (#{id},#{name},#{age});
</insert>

<delete id="deleteUserById" parameterType="java.lang.Long">
 delete from t_user where id=#{id}
</delete>

<update id="updateUserById" parameterType="com.somta.springboot.pojo.User" >
	update t_user set 
	<trim  suffixOverrides="," >
	<if test="id != null and id != ''">
		id=#{id},
	</if>
	<if test="name != null and name != ''">
		name=#{name},
	</if>
	<if test="age != null and age != ''">
		age=#{age},
	</if>
	</trim> where id=#{id}
</update>

<select id="queryUserById" resultMap="BaseResultMap" parameterType="java.lang.Long">
	select <include refid="Base_Column_List" /> 
	from t_user where id = #{id}
</select>

<select id="queryUserList" resultMap="BaseResultMap">
	select <include refid="Base_Column_List" /> 
	from t_user
</select>

</mapper>

五、修改相关配置文件和MyBatis配置

@SpringBootApplication
@MapperScan("com.somta.springboot.dao")
public class Application {
	public static void main(String [] args) {
		SpringApplication.run(Application.class, args);
    }
}

```java spring: datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false username: root password: 123456

mybatis:
mapper-locations: classpath:mybatis/**/Mysql_Mapper.xml

通过@MapperScan("com.somta.springboot.dao")指定Dao层的包路径，通过mapper-locations配置了MyBatis文件的扫描路径，达到对应映射的效果

**六、编写单元测试类**

```java
/**
 * 
 * @author 明天的地平线
 * 
 * SpringBoot 之前的版本配置单元测试类时使用 @SpringApplicationConfiguration(Application.class)
 * SpringBoot 1.5.9  改用@SpringBootTest(classes = Application.class)
 * 
 *
 */
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = Application.class)
public class MyBatisTest {

	@Autowired
	private UserDao userDao;
	
	/**
	 * 新增用户
	 * @throws Exception
	 */
	@Test
	public void testAddUser() throws Exception {
		User user = new User();
		user.setId(889L);
		user.setName("zhangsan");
		user.setAge(12);
		userDao.addUser(user);
	}
	
	/**
	 * 删除用户
	 * @throws Exception
	 */
	@Test
	public void testDelUser() throws Exception {
		userDao.deleteUserById(889L);
	}
	
	/**
	 * 修改用户信息
	 * @throws Exception
	 */
	@Test
	public void testUpdUser() throws Exception {
		User user = new User();
		user.setId(2L);
		user.setName("zhangsan99");
		user.setAge(122);
		userDao.updateUserById(user);
	}
	
	/**
	 * 查询用户
	 * @throws Exception
	 */
	@Test
	public void testQueryUser() throws Exception {
		User user = userDao.queryUserById(2L);
		System.out.println(user.getName());
	}
	
	/**
	 * 查询所有用户
	 * @throws Exception
	 */
	@Test
	public void testQueryUserList() throws Exception {
		List<User> list = userDao.queryUserList();
		for (User user : list) {
			System.out.println(user.getName());
		}
	}
	
}

Git代码地址：https://gitee.com/Somta/SpringBoot/tree/master/SpringBoot-mybatis
原文地址：http://somta.com.cn/#/blog/view/b8333bea30ca4500abb01e470121ba14