数据源配置类一：

import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.session.SqlSessionFactory;
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.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = {"com.xxx.xxx.xx.xx.xxx"}, sqlSessionFactoryRef = "sqlSessionFactory2")
public class MysqlDataSourceConfig {

    @Bean(name = "dataSource2")
    @ConfigurationProperties(prefix = "spring.datasource.datasource2")
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "sqlSessionFactory2")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSource2") DataSource dataSource) throws Exception {
        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setMapUnderscoreToCamelCase(true);

        MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setConfiguration(configuration);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/*.xml"));
        return bean.getObject();
    }

    @Bean(name = "transactionManager2")
    public DataSourceTransactionManager transactionManager(@Qualifier("dataSource2") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "sqlSessionTemplate2")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("sqlSessionFactory2") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

数据源配置类二：

import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.session.SqlSessionFactory;
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.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@EnableJpaRepositories({"xxx.xxx.xx.xx.xx"})
@MapperScan(basePackages = {"xx.xx.xx.xx.xx.xx"}, sqlSessionFactoryRef = "sqlSessionFactory")
public class PrimaryDataSourceConfig {

    @Bean
    @ConfigurationProperties(prefix = "mybatis-plus.configuration")
    public MybatisConfiguration globalConfiguration() {
        return new MybatisConfiguration();
    }

    @Bean(name = "dataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    @Primary
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "sqlSessionFactory")
    @Primary
    public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSource") DataSource dataSource) throws Exception {
        MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        //这里将下划线映射为驼峰的配置引入
        bean.setConfiguration(globalConfiguration());
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/*.xml"));
        return bean.getObject();
    }

    @Bean(name = "transactionManager")
    @Primary
    public DataSourceTransactionManager transactionManager(@Qualifier("dataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "sqlSessionTemplate")
    @Primary
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("sqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

yml相应配置

  datasource:
    primary:
      jdbc-url: jdbc:sqlserver://xx.xx.xx.xx:xx;databasename=xxx
      driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver
      username: xxx
      password: xxx
    datasource2:
      jdbc-url: jdbc:mysql://xxx.xxx:3306/xxx?useUnicode=true&serverTimezone=GMT%2b8&autoReconnect=true&characterEncoding=utf-8
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: xxx
      password: xxx