1.引入依赖：

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.2.0</version>
</dependency>

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
    <version>3.2.0</version>
</dependency>

 <dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.21</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.28</version>
</dependency>

2.yaml文件配置：

server:
  port: 8080

spring:
  application:
    name: test-datasource-provider
  # 多数据源配置
  datasource:
    dynamic:
      # 设置默认的数据源或者数据源组，默认值即为master
      primary: master 
      strict: false 
      datasource:
	      # 主数据库配置，master为数据源名称，配合DS注解使用
        master:
          url: jdbc:mysql://ip1:3306/test_db?useUnicode=true&serverTimezone=Asia/Shanghai&characterEncoding=UTF-8&useSSL=false&rewriteBatchedStatements=true
          username: root
          password: 123456
          driver-class-name: com.mysql.cj.jdbc.Driver
          druid:
            max-active: 30
            initial-size: 10
            max-wait: 60000
            min-idle: 1
            time-between-eviction-runs-millis: 60000
            min-evictable-idle-time-millis: 300000
            validation-query: select 'x'
            test-while-idle: true
            test-on-borrow: false
            test-on-return: false
            pool-prepared-statements: true
            max-open-prepared-statements: 20
            filter: stat,wall
            # 启用ConfigFilter
            config:
              enabled: true
            stat:
              enabled: true
              # 慢SQL记录
              log-slow-sql: true
              slow-sql-millis: 30000
              merge-sql: false
            wall:
              function-check: false
              strict-syntax-check: false
              multi-statement-allow: true
        # 从数据库配置，slave为数据源名称，配合DS注解使用
        slave:
          url: jdbc:mysql://localhost:3306/test_db2?useUnicode=true&serverTimezone=Asia/Shanghai&characterEncoding=UTF-8&useSSL=false&rewriteBatchedStatements=true
          username: root
          password: 123456789
          driver-class-name: com.mysql.cj.jdbc.Driver
          druid:
            max-active: 40
            initial-size: 15
            max-wait: 60000
            min-idle: 1
            time-between-eviction-runs-millis: 60000
            min-evictable-idle-time-millis: 300000
            validation-query: select 'x'
            test-while-idle: true
            test-on-borrow: false
            test-on-return: false
            pool-prepared-statements: true
            max-open-prepared-statements: 20
            filter: stat,wall
            # 启用ConfigFilter
            config:
              enabled: true
            stat:
              enabled: true
              # 慢SQL记录
              log-slow-sql: true
              slow-sql-millis: 30000
              merge-sql: false
            wall:
              function-check: false
              strict-syntax-check: false
              multi-statement-allow: true
    # 监控配置
    druid:
      web-stat-filter:
        url-pattern: /*
        exclusions: "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"
      stat-view-servlet:
        url-pattern: /druid/*
        reset-enable: false
        # 是否开启监控页面
        enabled: true
        login-username: admin
        login-password: "123456"
      #连接池重连检测
      testConnectionOnCheckout: false
      testConnectionOnCheckin: true
      idleConnectionTestPeriod: 3600 #单位是妙,即1小时

# mybatis 配置
mybatis-plus:
  mapper-locations: classpath:mapper/*Mapper.xml
  type-aliases-package: com.zhou.entity
  configuration:
    map-underscore-to-camel-case: true
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

3.启动类排除Druid数据源的自动装配配置

@SpringBootApplication(exclude = {DruidDataSourceAutoConfigure.class})

4.测试

• 访问http://应用服务器ip:8080/druid，查看配置是否生效，如果配置成功会出现以下页面：

账号密码为yaml文件配置的admin和123456

• 在需要切换数据源的方法上标注@DS注解，指定要切换的数据源，如果没有配置DS注解，采用默认数据源，即前面配置的master

示例如下：

读取从数据源的数据：

@Override
@DS("slave")
public IPage<Map> query(Subject subject){
     return subjectMapper.query(subject.getPage(), subject);
}

读取主数据源的数据：

@Override
@DS("master")// 主数据源为默认数据源，可以不用配置这个注解
public IPage<Map> query(Subject subject){
     return subjectMapper.query(subject.getPage(), subject);
}