SpringBoot如何通过yml方式整合Mybatis

　　本来打算写个使用Sharding-JDBC的例程，但是在搭建Mybatis的过程中，一波三折，因为好久没搭建项目了，另外加上换了电脑。所以很破折，在这里记录一下Spring Boot整合Mybatis吧。可能很简单，但是我长时间没用忘记了，我这里备忘一下吧。

一、项目目录结构

　　注意这里Application文件的位置，它是与controller、entity、mapper、service等包处于并列的关系。

二、数据库文件

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for t_user_00
-- ----------------------------
DROP TABLE IF EXISTS `t_user_00`;
CREATE TABLE `t_user_00` (
 `id` int(0) NOT NULL AUTO_INCREMENT,
 `user_id` int(0) NOT NULL,
 `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
 `age` int(0) NOT NULL,
 PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;

三、pom.xml

<?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>2.1.13.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>com.gougou</groupId>
  <artifactId>shardingjdbc-shardingtable-demo</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>shardingjdbc-shardingtable-demo</name>
  <description>shardingjdbc-shardingtable-demo</description>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <optional>true</optional>
    </dependency>
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>1.3.2</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
    </dependency>
  </dependencies>

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

</project>

四、application.yml

# 数据源
spring:
 application:
  name: shardingjdbc-shardingtable-demo
 datasource:
  url: jdbc:mysql://localhost:3306/sharding_0?serverTimezone=UTC
  username: root
  password: root
  driver-class-name: com.mysql.jdbc.Driver
  dbcp2:
   min-idle: 5                # 数据库连接池的最小维持连接数
   initial-size: 5              # 初始化连接数
   max-total: 5                # 最大连接数
   max-wait-millis: 150            # 等待连接获取的最大超时时间

# mybatis配置
mybatis:
 mapper-locations: classpath:mapper/*.xml  # mapper映射文件位置
 type-aliases-package: com.gouggou.shardingtable.entity  # 实体类所在的位置
 configuration:
  log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  #用于控制台打印sql语句

五、启动类Application

　　说明：

　　1、@MapperScan的：扫描mapper接口的位置

　　2、@ComponentScan：如果Application文件的位置不是与controller、entity、mapper、service等包处于并列的关系。就要用此注解，否则可以不用；

@MapperScan("com.gouggou.shardingtable.mapper")
@SpringBootApplication
public class Application {

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

}

六、controller

@RequestMapping("student")
@RestController
public class UserController {

  @Autowired
  private UserService userService;

  @RequestMapping("save")
  public String save() {
    User user = new User();
    user.setUserId(new Random().nextInt( 1000 ) + 1);
    user.setName("张三"+user.getUserId());
    user.setAge(new Random().nextInt( 80 ) + 1);
    userService.insert(user);
    return user.getName()+"创建成功！";
  }

}

七、service

public interface UserService {
  Integer insert(User u);
  List<User> findAll();
  List<User> findByUserIds(List<Integer> userIds);
}

@Service
public class UserServiceImpl implements UserService {

  @Autowired
  private UserMapper userMapper;

  @Override
  public Integer insert(User u) {
    return userMapper.insert(u);
  }

  @Override
  public List<User> findAll() {
    return userMapper.findAll();
  }

  @Override
  public List<User> findByUserIds(List<Integer> userIds) {
    return userMapper.findByUserIds(userIds);
  }
}

八、entity

@Data
public class User implements Serializable {
  private static final long serialVersionUID = -5514139686858156155L;
  private Integer id;
  private Integer userId;
  private String name;
  private Integer age;
}

九、Mapper

@Repository
public interface UserMapper {
  Integer insert(User u);
  List<User> findAll();
  List<User> findByUserIds(List<Integer> userIds);
}

<?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.gouggou.shardingtable.mapper.UserMapper" >
  <resultMap id="resultMap" type="com.gouggou.shardingtable.entity.User" >
    <id column="id" property="id" jdbcType="INTEGER" />
    <result column="user_id" property="userId" jdbcType="INTEGER" />
    <result column="name" property="name" jdbcType="VARCHAR" />
    <result column="age" property="age" jdbcType="INTEGER" />
  </resultMap>

  <insert id="insert">
  insert into t_user_00 (user_id,name,age) values (#{userId},#{name},#{age})
 </insert>

  <select id="findAll" resultMap="resultMap">
    select <include refid="columnsName"/> from t_user_00
  </select>

  <select id="findByUserIds" resultMap="resultMap">
    select <include refid="columnsName"/> from t_user_00 where user_id in (
    <foreach collection="list" item="item" separator=",">
      #{item}
    </foreach>
    )

  </select>

  <sql id="columnsName">
   id,user_id,name,age
 </sql>
</mapper>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。