配置

首先，在application配置文件中添加多个数据数据源，如下：

server:
  port: 8803
spring:
  datasource:
    sys:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://localhost:3306/spring-boot-demo?useSSL=false&useUnicode=true&characterEncoding=utf8
      username: root
      password:
    fin:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://localhost:3306/spring-boot-demo-backup?useSSL=false&useUnicode=true&characterEncoding=utf8
      username: root
      password:

# mybatis映射文件路径
mybatis:
  mapper-locations: classpath*:mappers/*Mapper.xml

这里配置了sys和fin两个数据源，分别对应spring-boot-demo和spring-boot-demo-backup数据库。

然后，对这两个数据源进行配置，配置类如下：

@Configuration
@MapperScan(basePackages = "com.greedystar.sample4.fin.dao", sqlSessionTemplateRef = "finSqlSessionTemplate")
public class FinDataSourceConfig {

    @Bean(name = "finDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.fin")
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        return dataSource;
    }

    @Bean(name = "finSqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("finDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/fin/*Mapper.xml"));
        return bean.getObject();
    }

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

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

}

@Configuration
@MapperScan(basePackages = "com.greedystar.sample4.sys.dao", sqlSessionTemplateRef = "sysSqlSessionTemplate")
public class SysDataSourceConfig {

    @Bean(name = "sysDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.sys")
    @Primary
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        return dataSource;
    }

    @Bean(name = "sysSqlSessionFactory")
    @Primary
    public SqlSessionFactory sqlSessionFactory(@Qualifier("sysDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/sys/*Mapper.xml"));
        return bean.getObject();
    }

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

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

}

这里需要注意，在两个数据源的配置中要特别区分DAO接口的包路径和映射文件的路径，当我们使用不同的DAO对象时便会访问不同的数据源。

测试

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = Sample4Application.class)
public class Test {
    @Autowired
    private UserDao userDao;
    @Autowired
    private RoleDao roleDao;

    @org.junit.Test
    public void test() {
        System.out.println(JSON.toJSON(userDao.findAllList()));
        System.out.println(JSON.toJSON(roleDao.findAllList()));
    }
}