mybatis-plus切换Druid数据源的完整代码和配置文件配置

首先，需要在pom.xml中添加依赖，如下：

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>${mybatis-plus.version}</version>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.6</version>
</dependency>

然后，需要在application.yml中配置Druid数据源和Mybatis-plus的配置，如下：

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/db1?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
    username: root
    password: root
    druid:
      max-active: 20
      initial-size: 1
      max-wait: 60000
      min-idle: 1
      time-between-eviction-runs-millis: 60000
      min-evictable-idle-time-millis: 300000
      validation-query: SELECT 1 FROM DUAL
      test-while-idle: true
      test-on-borrow: false
      test-on-return: false

mybatis-plus:
  mapper-locations: classpath:/mapper/*.xml
  global-config:
    db-config:
      id-type: auto
      field-strategy: not_empty
      table-prefix: t_
      logic-delete-value: 1
      logic-not-delete-value: 0
  configuration:
    map-underscore-to-camel-case: true

接着，我们需要创建一个数据源切换的工具类，如下：

public class DynamicDataSourceContextHolder {
    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();

    public static void setDataSourceType(String dataSourceType) {
        CONTEXT_HOLDER.set(dataSourceType);
    }

    public static String getDataSourceType() {
        return CONTEXT_HOLDER.get();
    }

    public static void clearDataSourceType() {
        CONTEXT_HOLDER.remove();
    }
}

然后，我们需要创建一个切面，用来在方法执行前切换数据源，如下：

@Component
@Aspect
public class DynamicDataSourceAspect {
    @Pointcut("@annotation(com.example.demo.annotation.DataSource)")
    public void dataSourcePointCut() {}

    @Around("dataSourcePointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        DataSource dataSource = signature.getMethod().getAnnotation(DataSource.class);
        if (dataSource == null) {
            DynamicDataSourceContextHolder.setDataSourceType("db1");
        } else {
            DynamicDataSourceContextHolder.setDataSourceType(dataSource.value());
        }
        try {
            return point.proceed();
        } finally {
            DynamicDataSourceContextHolder.clearDataSourceType();
        }
    }
}

在需要使用不同数据源的方法上，我们可以使用@DataSource注解来指定数据源，如下：

@DataSource("db2")
public List<User> selectUserList() {
    return userMapper.selectList(null);
}

最后，我们需要在配置类中配置多个数据源，如下：

@Configuration
public class DataSourceConfig {
    @Bean
    @ConfigurationProperties("spring.datasource.druid.db1")
    public DataSource db1() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @ConfigurationProperties("spring.datasource.druid.db2")
    public DataSource db2() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public DataSource dataSource(DataSource db1, DataSource db2) {
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put("db1", db1);
        targetDataSources.put("db2", db2);
        DynamicRoutingDataSource dataSource = new DynamicRoutingDataSource();
        dataSource.setTargetDataSources(targetDataSources);
        dataSource.setDefaultTargetDataSource(db1);
        return dataSource;
    }
}

以上就是Mybatis-plus切换Druid数据源的完整代码和配置文件配置。其中，DynamicRoutingDataSource是动态数据源的实现类，需要自行实现。