引入依赖

---

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

1. 自动检测工程中的DataSource
2. 创建并注册SqlSessionFactory实例
3. 创建并注册SqlSessionTemplate实例
4. 自动扫描mappers

---

配置

        数据源

ewriteBatchedStatements=true  开启真正批处理 Oracle 默认开启

spring:
 datasource:
   username: root
   password: root
   url: jdbc:mysql://127.0.0.1:3307/sql?characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8&allowPublicKeyRetrieval=true&rewriteBatchedStatements=true
   driver-class-name: com.mysql.cj.jdbc.Driver

连接池

spring:
  datasource:
    hikari:
      auto-commit: true
      data-source-properties:
        # 缓存 SQL 语句
        cachePrepStmts: true
        # 缓存大小
        prepStmtCacheSize: 250
        # 缓存 SQL 的长度限制
        prepStmtCacheSqlLimit: 2048
        # 服务器预编译
        useServerPrepStmts: true
      pool-name: Hikari
      #      最小连接数
      minimum-idle: 20
      maximum-pool-size: 500
      # 等待连接池分配连接的时间 毫秒 默认 30
      connection-timeout: 500
      #      连接超时的最大 时常 毫秒 默认10分钟
      idle-timeout: 60000
      #      连接的生命时常 超时没有被使用 则回收 毫秒 默认30分钟
      max-lifetime: 30000000
      connection-test-query: select 1

Mybatis配置

参考 mybatis-spring-boot-autoconfigure – Introductionhttp://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/index.html

---

mybatis:
 type-aliases-package: com.du.bean
 mapper-locations:
   - classpath:mapper/**/*.xml
 configuration:
   map-underscore-to-camel-case: true
   cache-enabled: true
   use-generated-keys: true
   lazy-loading-enabled: true
   aggressive-lazy-loading: false
logging:
 level:
   com.du.mapper: DEBUG

指定配置文件XMl

mybatis:

    config-location: classpath:mybatis/mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE configuration

        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

        "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

<!--使用xml配置sql-->

    <settings>

        <setting name="mapUnderscoreToCamelCase" value="true"/>

        <setting name="cacheEnabled" value="true"/>

    </settings>

</configuration>

java配置类

@Configuration
public class MyBatisConfig {


    /**

     * @return ConfigurationCustomizer

     */
    @Bean
    public ConfigurationCustomizer configurationCustomizer() {

        return configuration -> configuration.setMapUnderscoreToCamelCase(true);

    }
}

启动类

@SpringBootApplication
@MapperScan(value = "com.du.mapper")
public class DataBase {

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

    }
}