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上篇文章我们介绍了 Spring Boot 对传统 JdbcTemplate 的集成，这篇文章我给大家介绍 Spring Boot 集成 MyBatis。这里分别介绍注解方式以及XML方式的整合。

一、准备数据表

CREATE TABLE `spring_boot`.`article`  (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) NULL COMMENT '文章标题',
  `author` varchar(255) NULL COMMENT '作者',
  PRIMARY KEY (`id`)
) COMMENT = '文章表';

二、添加依赖

<dependencies>
	
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>2.2.0</version>
		</dependency>
		
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
</dependencies>

大家要注意依赖版本兼容性

三、配置数据源

spring.datasource.url = jdbc:mysql://139.196.20.xxx:3306/spring_boot?useUnicode=true&characterEncoding=utf-8
spring.datasource.username = root
spring.datasource.password = 123456
spring.datasource.driver-class-name = com.mysql.cj.jdbc.Driver

四、编写领域对象

@Data
@NoArgsConstructor
public class Blog 
  private Integer id;
  private String title;
  private String author;

五、注解配置方式

新增

@RestController
public class BlogController 

  @Autowired
  public BlogService blogService;

  /**
   * 新增一篇文章
   *
   * @param blog 文章实体类
   * @return
   */
  @PostMapping(value = "/create")
  public Object create(@RequestBody Blog blog) 
    if (StringUtils.isBlank(blog.getTitle())) 
      return ResponseUtil.fail(ResultEnums.BAD_ARGUMENT_VALUE.getCode(), "请输入文章标题");
    
    if (StringUtils.isBlank(blog.getAuthor())) 
      return ResponseUtil.fail(ResultEnums.BAD_ARGUMENT_VALUE.getCode(), "请输入文章作者");
    
    return blogService.create(blog);
  


@Service
public class BlogServiceImpl implements BlogService 

  @Autowired
  private BlogMapper blogMapper;

  @Override
  public Object create(Blog blog) 
    int count = blogMapper.create(blog);
    if (count > 0) 
      return ResponseUtil.ok("插入成功");
     else 
      return ResponseUtil.fail(ResultEnums.SERIOUS.getCode(), "插入失败");
    
  


@Mapper
public interface BlogMapper 
  @Insert("INSERT INTO article(title, author) VALUES(#title, #author)")
  int create(Blog blog);

修改

@RestController
public class BlogController 

  @Autowired
  public BlogService blogService;

  /**
   * 通过id修改文章
   *
   * @param blog
   * @return
   */
  @PostMapping(value = "/updateById")
  public Object updateById(@RequestBody Blog blog) 
    if (StringUtils.isBlank(blog.getTitle())) 
      return ResponseUtil.fail(ResultEnums.BAD_ARGUMENT_VALUE.getCode(), "请输入文章标题");
    
    if (StringUtils.isBlank(blog.getAuthor())) 
      return ResponseUtil.fail(ResultEnums.BAD_ARGUMENT_VALUE.getCode(), "请输入文章作者");
    
    return blogService.updateById(blog);
  


@Service
public class BlogServiceImpl implements BlogService 

  @Autowired
  private BlogMapper blogMapper;

  @Override
  public Object updateById(Blog blog) 
    int count = blogMapper.updateById(blog);
    if (count > 0) 
      return ResponseUtil.ok("修改成功");
     else 
      return ResponseUtil.fail(ResultEnums.SERIOUS.getCode(), "修改失败");
    
  


@Mapper
public interface BlogMapper 
  @Update("UPDATE article SET title=#title,author=#author WHERE id=#id")
  int updateById(Blog blog);

查询

@RestController
public class BlogController 

  @Autowired
  public BlogService blogService;

  /**
   * 查询所有文章
   *
   * @return
   */
  @GetMapping(value = "/getAll")
  public List<Blog> getAll() 
    return blogService.getAll();
  


  /**
   * 通过标题查询文章
   *
   * @param title
   * @return
   */
  @GetMapping(value = "/getByTitle")
  public Object getByTitle(String title) 
    if (StringUtils.isBlank(title)) 
      return ResponseUtil.fail(ResultEnums.BAD_ARGUMENT_VALUE.getCode(), "请输入文章标题");
    
    return blogService.getByTitle(title);
  


@Service
public class BlogServiceImpl implements BlogService 

  @Autowired
  private BlogMapper blogMapper;

  @Override
  public List<Blog> getAll() 
    return blogMapper.getAll();
  


  @Override
  public List<Blog> getByTitle(String title) 
    return blogMapper.getByTitle(title);
  


@Mapper
public interface BlogMapper 

  @Select("SELECT * FROM article")
  @Results(
    @Result(column = "id", property = "id", javaType = Integer.class),
    @Result(property = "title", column = "title", javaType = String.class),
    @Result(property = "author", column = "author", javaType = String.class)
  )
  List<Blog> getAll();

  @Select("SELECT * FROM article WHERE title = #title")
  @Results(
    @Result(column = "id", property = "id", javaType = Integer.class),
    @Result(property = "title", column = "title", javaType = String.class),
    @Result(property = "author", column = "author", javaType = String.class)
  )
  List<Blog> getByTitle(String title);

删除

@RestController
public class BlogController 

  @Autowired
  public BlogService blogService;

  /**
   * 通过ID删除文章
   *
   * @param id
   * @return
   */
  @PostMapping(value = "/deleteById")
  public Object deleteById(Integer id) 
    if (null == id || 0 == id.longValue()) 
      return ResponseUtil.fail(ResultEnums.BAD_ARGUMENT_VALUE.getCode(), "请输入文章id");
    
    return blogService.deleteById(id);
  


@Service
public class BlogServiceImpl implements BlogService 

  @Autowired
  private BlogMapper blogMapper;
  
  @Override
  public Object deleteById(Integer id) 
    int count = blogMapper.deleteById(id);
    if (count > 0) 
      return ResponseUtil.ok("删除成功");
     else 
      return ResponseUtil.fail(ResultEnums.SERIOUS.getCode(), "删除失败");
    
  


@Mapper
public interface BlogMapper 
  @Delete("DELETE FROM article WHERE id = #id")
  int deleteById(Integer id);

六、XML配置方式

修改application.properties 配置文件

#指定bean所在包
mybatis.type-aliases-package=com.fish.chapter6.domain
#指定映射文件
mybatis.mapperLocations=classpath:mapper/*.xml

新增

@Mapper
public interface BlogMapper 
  int create(Blog blog);

<insert id="create" parameterType="com.fish.chapter6.domain.Blog">
    INSERT INTO article (title, author) VALUES (#title, #author)
</insert>

修改

@Mapper
public interface BlogMapper 
  int updateById(Blog blog);

<update id="updateById" parameterType="com.fish.chapter6.domain.Blog">
    UPDATE article SET title = #title, author = #author WHERE id = #id
</update>

查询

@Mapper
public interface BlogMapper 

  List<Blog> getAll();
  
  List<Blog> getByTitle(@Param("title") String title);
  

<select id="getByTitle" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_List"/>
        from article
        <where>
            <if test="title != null and title !=''">
                AND title = #title,jdbcType=VARCHAR
            </if>
        </where>
</select>

<select id="getAll" resultMap="BaseResultMap">
    select
    <include refid="Base_Column_List"/>
    from article
</select>

删除

@Mapper
public interface BlogMapper 
  int deleteById(@Param("id") Integer id);

<delete id="deleteById" parameterType="java.lang.Integer">
    DELETE FROM article WHERE id = #id
</delete>

更多mybatis数据访问操作的使用请参考：MyBatis官方中文参考文档

彩蛋，很多小伙伴会发现一个问题，项目启动一段时间放那里不动，然后在访问接口时，就会报错，这和我们使用的数据源有关（Hikari），在后面《数据源详解》章节我会教大家如何解决。

七、源码

本文的相关例子可以查看下面仓库中的 chapter6 目录：

• Gitee：https://gitee.com/hezhiyuan007/spring-boot-study
• Github：https://github.com/java-fish-0907/spring-boot-study