SpringBoot系列：Spring Boot多数据源，Mybatis动态数据源方式

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
 
import javax.sql.DataSource;
 
@Configuration
@MapperScan(basePackages = "com.example.mapper.dynamic", sqlSessionTemplateRef  = "dynamicSqlSessionTemplate")
public class DynamicDataSourceConfig {
 
    @Bean(name = "dynamicDataSource")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.dynamic")
    public DataSource dynamicDataSource() {
        return DataSourceBuilder.create().build();
    }
 
    @Bean(name = "dynamicSqlSessionFactory")
    @Primary
    public SqlSessionFactory dynamicSqlSessionFactory(@Qualifier("dynamicDataSource") DataSource dynamicDataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dynamicDataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/dynamic/*.xml"));
        return bean.getObject();
    }
 
    @Bean(name = "dynamicTransactionManager")
    @Primary
    public DataSourceTransactionManager dynamicTransactionManager(@Qualifier("dynamicDataSource") DataSource dynamicDataSource) {
        return new DataSourceTransactionManager(dynamicDataSource);
    }
 
    @Bean(name = "dynamicSqlSessionTemplate")
    @Primary
    public SqlSessionTemplate dynamicSqlSessionTemplate(@Qualifier("dynamicSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

这个代码示例展示了如何在Spring Boot应用程序中配置和使用多个数据源。它定义了一个名为dynamicDataSource的数据源，以及相应的SqlSessionFactory、TransactionManager和SqlSessionTemplate。通过@MapperScan注解，指定了使用这个数据源的mapper接口所在的包。这个配置适用于需要根据不同的数据源执行SQL操作的场景，如多租户系统或者按功能划分模块的数据库。