01. AbstractRoutingDataSource（Spring）

@Component
@Primary 
public class DynamicDataSource extends AbstractRoutingDataSource {
    // 更改数据源时切换 ThreadLocal 即可
    public static ThreadLocal<String> name = new ThreadLocal<>();
    @Autowired
    DataSource dataSource1;
    @Autowired
    DataSource dataSource2;

    @Override
    protected Object determineCurrentLookupKey() {
        return name.get();
    }
    @Override
    public void afterPropertiesSet() {
        // 为targetDataSources初始化所有数据源
        Map<Object, Object> targetDataSources=new HashMap<>();
        targetDataSources.put("W",dataSource1);
        targetDataSources.put("R",dataSource2);
        super.setTargetDataSources(targetDataSources);
        // 为defaultTargetDataSource 设置默认的数据源
        super.setDefaultTargetDataSource(dataSource1);
        super.afterPropertiesSet();
    }
}

02. SqlSessionFactory（MyBatis）

@Configuration
// 使用不同数据源的接口放到不同的 mapper 包下即可
@MapperScan(basePackages = "com.tuling.datasource.dynamic.mybatis.mapper.r", sqlSessionFactoryRef="rSqlSessionFactory")
public class RMyBatisConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.datasource2")
    public DataSource dataSource2() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public SqlSessionFactory rSqlSessionFactory() throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource2());
        // 指定主库对应的mapper.xml文件
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/r/*.xml"));
        return sessionFactory.getObject();
    }

    @Bean
    public DataSourceTransactionManager rTransactionManager(){
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSource2());
        return dataSourceTransactionManager;
    }

    @Bean
    public TransactionTemplate rTransactionTemplate(){
        return new TransactionTemplate(rTransactionManager());
    }
}

03. dynamic-datasource

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
    <version>3.5.0</version>
</dependency>

spring:
  datasource:
    dynamic:
      # 设置默认的数据源或者数据源组,默认值即为master
      primary: master
      # 严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源
      strict: false
      datasource:
        master:
          url: jdbc:mysql://127.0.0.1:3306/datasource1?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF8&useSSL=false
          username: root
          password: 123456
          initial-size: 1
          min-idle: 1
          max-active: 20
          test-on-borrow: true
          driver-class-name: com.mysql.cj.jdbc.Driver
        slave_1:
          url: jdbc:mysql://127.0.0.1:3306/datasource2?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF8&useSSL=false
          username: root
          password: 123456
          initial-size: 1
          min-idle: 1
          max-active: 20
          test-on-borrow: true
          driver-class-name: com.mysql.cj.jdbc.Driver