一、配置文件

jdk环境：1.8 配置了双数据源springboot+druid+pgsql，application.properties配置修改如下：

#当前入库主数据库
spring.primary.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.primary.datasource.driver-class-name=org.postgresql.Driver
spring.primary.datasource.url=jdbc:postgresql://localhost:5432/testdb
spring.primary.datasource.username=postgres
spring.primary.datasource.password=postgres
#
#从数据库
spring.secondary.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.secondary.datasource.driver-class-name=org.postgresql.Driver
spring.secondary.datasource.url=jdbc:postgresql://localhost:5432/postgres
spring.secondary.datasource.username=postgres
spring.secondary.datasource.password=postgres

spring.datasource.druid.initial-size=5
spring.datasource.druid.min-idle=5
spring.datasource.druid.max-active=20

二、Java代码配置新增

主数据库注入

/**
 * @Author yang
 * @Date 2023/2/20 11:10
 * @Version 1.0
 */
import com.alibaba.druid.pool.DruidDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
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 = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {
    // 精确到master目录，以便跟其他数据源隔离
    static final String PACKAGE = "com.xx.dao.master";
    static final String MAPPER_LOCATION = "classpath*:com/xx/mapper/master/*.xml";

    @Value("${spring.primary.datasource.url}")
    private String url;

    @Value("${spring.primary.datasource.username}")
    private String user;

    @Value("${spring.primary.datasource.password}")
    private String password;

    @Value("${spring.primary.datasource.driver-class-name}")
    private String driverClass;

    private SqlSessionFactory mSessionFactory;


    @Bean(name = "masterDataSource")
    @Primary
    public DataSource masterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean(name = "masterTransactionManager")
    @Primary
    public DataSourceTransactionManager masterTransactionManager() {
        return new DataSourceTransactionManager(masterDataSource());
    }

    @Bean(name = "masterSqlSessionFactory")
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(masterDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(MasterDataSourceConfig.MAPPER_LOCATION));
        //开启驼峰
        sessionFactory.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);
        this.mSessionFactory = sessionFactory.getObject();
        return sessionFactory.getObject();
    }

    /**
     * 获取主库 SessionFactory
     * @return
     */
    public SqlSessionFactory getMSessionFactory(){
        return mSessionFactory;
    }

}

从数据库Java代码：

/**
 * @Author yang
 * @Date 2023/2/20 11:52
 * @Version 1.0
 */
@Configuration
// 扫描 Mapper 接口并容器管理
@MapperScan(basePackages = SecondDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "secondSqlSessionFactory")
public class SecondDataSourceConfig {
    //精确到第二个数据库目录，以便跟其他数据源隔离
    static final String PACKAGE = "com.xx.dao.second";
    static final String MAPPER_LOCATION = "classpath*:com/xx/mapper/second/*.xml";

    @Value("${spring.secondary.datasource.url}")
    private String url;

    @Value("${spring.secondary.datasource.username}")
    private String user;

    @Value("${spring.secondary.datasource.password}")
    private String password;

    @Value("${spring.secondary.datasource.driver-class-name}")
    private String driverClass;

    @Bean(name = "secondDataSource")
    public DataSource clusterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean(name = "secondTransactionManager")
    public DataSourceTransactionManager clusterTransactionManager() {
        return new DataSourceTransactionManager(clusterDataSource());
    }

    @Bean(name = "secondSqlSessionFactory")
    public SqlSessionFactory clusterSqlSessionFactory(@Qualifier("secondDataSource") DataSource clusterDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(clusterDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(SecondDataSourceConfig.MAPPER_LOCATION));
        //开启驼峰
        sessionFactory.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);
        return sessionFactory.getObject();
    }
}

三、mapper接口、mybatis/xml文件配置

     这里就就不一一贴代码了，主要是接口对应mybatis xml配置文件。项目文件接口如下：

创建成以上目录就可以了，分别是dao接口、Java数据源配置、mybatis映射文件。

四、怎么使用

      通过以上配置文件和代码已经对两个数据源进行分割，直接正常使用访问代码即可，比如dao里面创建了testClass的操作

void insert(Test test);
void delete();

Controller层我们通过@Autowired注解 使用就可以了。

这里需要注意修改：

@MapperScan里面的basePackages

MAPPER_LOCATION变量的配置，这里主要是不同的数据源配置扫描不同的mybatis配置文件