二、springboot整合mybatis

1、新增repositoryModule

   （1）new -> new Module ->spring Initializr
   （2）修改pom文件
      <parent>
    <groupId>shmilylyp</groupId>
    <artifactId>shmilylyp</artifactId>
    <version>1.0-SNAPSHOT</version>
</parent>
<groupId>com.shmilylyp</groupId>
<artifactId>repository</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>repository</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>com.shmilylyp</groupId>
        <artifactId>bean</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
</dependencies>

2、添加相应的依赖

  <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.12</version>
    </dependency>
    <!-- alibaba的druid数据库连接池 -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.2</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.1</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.1.9</version>
    </dependency>

3、在application.yml文件中创建数据库和mybatis相关的配置

（1）数据库的配置

spring:
  datasource:
    name: mysql_set
    type: com.alibaba.druid.pool.DruidDataSource
    #druid相关配置
    druid:
      #监控统计拦截的filters
      filters: stat
      driver-class-name: com.mysql.cj.jdbc.Driver
      #基本属性
      url: jdbc:mysql://127.0.0.1:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
      username: root
      password: 123123
      #配置初始化大小/最小/最大
      initial-size: 1
      min-idle: 1
      max-active: 20
      #获取连接等待超时时间
      max-wait: 60000
      #间隔多久进行一次检测，检测需要关闭的空闲连接
      time-between-eviction-runs-millis: 60000
      #一个连接在池中最小生存的时间
      min-evictable-idle-time-millis: 300000
      validation-query: SELECT 'x'
      test-while-idle: true
      test-on-borrow: false
      test-on-return: false
      #打开PSCache，并指定每个连接上PSCache的大小。oracle设为true，mysql设为false。分库分表较多推荐设置为false
      pool-prepared-statements: false
      max-pool-prepared-statement-per-connection-size: 20

（2）mybatis配置

mybatis:
  mapper-locations: classpath:mapper/*.xml  #注意：一定要对应mapper映射xml文件的所在路径
  type-aliases-package: com.shmilylyp.model  # 注意：对应实体类的路径

4、创建mapper和接口

（1）mapper.xml

    <?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.shmilylyp.repository.UserRepository">
  <resultMap id="userReturn" type="com.shmilylyp.bean.UserBean">
      <id column="id" property="id"></id>
      <result column="name" property="name"/>
      <result column="age" property="age"/>
  </resultMap>
  <sql id="Base_Column_List">
      id, name, age
  </sql>
  <select id="getUserList" resultMap="userReturn">
      select
      <include refid="Base_Column_List"/>
      from
      users
  </select>
</mapper>

(2) 创建对应的接口

    @Mapper
public interface UserRepository {
    //  接口名称要和配置文件中的id相对应
    List<UserBean> getUserList();
}