Dynamic DataSource 多数据源配置【 Springboot + DataSource + MyBatis Plus + Druid】

在Spring Boot项目中配置多数据源，可以使用Spring的AbstractRoutingDataSource进行动态数据源的路由。以下是一个简化的例子：

1. 配置数据源属性

spring:
  datasource:
    dynamic:
      primary: db1 # 设置主数据源
      datasource:
        db1:
          url: jdbc:mysql://localhost:3306/db1
          username: user1
          password: pass1
          driver-class-name: com.mysql.cj.jdbc.Driver
        db2:
          url: jdbc:mysql://localhost:3306/db2
          username: user2
          password: pass2
          driver-class-name: com.mysql.cj.jdbc.Driver

2. 创建动态数据源配置类

@Configuration
public class DynamicDataSourceConfig {
 
    @Primary
    @Bean
    public DataSource dynamicDataSource(@Value("${spring.datasource.dynamic.primary}") String primaryDs,
                                       @Qualifier("dynamicDataSource") DynamicDataSource dynamicDataSource,
                                       @Autowired DataSourceProperties dataSourceProperties) {
        dynamicDataSource.setPrimaryDataSource(dataSourceProperties.getDataSource(primaryDs));
        
        Map<Object, Object> dataSourceMap = dataSourceProperties.getDataSources();
        dataSourceMap.forEach((k, v) -> dynamicDataSource.addDataSource(k.toString(), (DataSource) v));
        
        return dynamicDataSource;
    }
}

3. 实现AbstractRoutingDataSource

public class DynamicDataSource extends AbstractRoutingDataSource {
    private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();
 
    public static void setDataSource(String dataSource) {
        contextHolder.set(dataSource);
    }
 
    public static String getDataSource() {
        return contextHolder.get();
    }
 
    public static void clearDataSource() {
        contextHolder.remove();
    }
 
    @Override
    protected Object determineCurrentLookupKey() {
        return getDataSource();
    }
    
    public void addDataSource(String key, DataSource dataSource) {
        this.setTargetDataSources(new HashMap<>(16));
        this.getTargetDataSources().put(key, dataSource);
        this.afterPropertiesSet();
    }
 
    public void setPrimaryDataSource(DataSource dataSource) {
        this.setDefaultTargetDataSource(dataSource);
    }
}

4. 使用动态数据源

   在你的服务层或者数据访问层，在执行操作前通过DynamicDataSource.setDataSource(dataSourceName)设置当前线程使用的数据源，操作完成后清除数据源设置DynamicDataSource.clearDataSource()。

例如：

public class SomeService {
    @Autowired