mybatis 双数据源配置

转载自http://blog.csdn.net/tracker_w/article/details/61202084

应用场景

项目需要同时连接两个不同的数据库A, B，并且它们都为主从架构，一台写库，多台读库。

多数据源

首先要将spring boot自带的DataSourceAutoConfiguration禁掉，因为它会读取application.properties文件的spring.datasource.*属性并自动配置单数据源。在@SpringBootApplication注解中添加exclude属性即可：

1. @SpringBootApplication(exclude = {
2. DataSourceAutoConfiguration.class
3. })
4. public class TitanWebApplication {
5. public static void main(String[] args) {
6. SpringApplication.run(TitanWebApplication.class, args);
7. }
8. }

然后在application.properties中配置多数据源连接信息：

1. # titan库
2. spring.datasource.titan-master.url=jdbc:mysql://X.X.X.X:port/titan?characterEncoding=UTF-8
3. spring.datasource.titan-master.username=
4. spring.datasource.titan-master.password=
5. spring.datasource.titan-master.driver-class-name=com.mysql.jdbc.Driver
6. # 连接池配置
7. # 省略
8.  
9. # 其它库
10. spring.datasource.db2.url=jdbc:mysql://X.X.X.X:port/titan2?characterEncoding=UTF-8
11. spring.datasource.db2.username=
12. spring.datasource.db2.password=
13. spring.datasource.db2.driver-class-name=com.mysql.jdbc.Driver

由于我们禁掉了自动数据源配置，因些下一步就需要手动将这些数据源创建出来：

1. @Configuration
2. public class DataSourceConfig {
3.  
4. @Bean(name = "titanMasterDS")

1.     @primary
2. @ConfigurationProperties(prefix = "spring.datasource.titan-master") // application.properteis中对应属性的前缀
3. public DataSource dataSource1() {
4. return DataSourceBuilder.create().build();
5. }
6.  
7.  
8.  
9.  
10. @Bean(name = "ds2")
11. @ConfigurationProperties(prefix = "spring.datasource.db2") // application.properteis中对应属性的前缀
12. public DataSource dataSource2() {
13. return DataSourceBuilder.create().build();
14. }
15.  
16. }

接下来需要配置两个mybatis的SqlSessionFactory分别使用不同的数据源：

1. @Configuration
2. @MapperScan(basePackages = {"titan.mapper"}, sqlSessionFactoryRef = "sqlSessionFactory1")
3. public class MybatisDbAConfig {
4.  
5. @Autowired

1. @Qualifier("titanMasterDS")
2. private DataSource ds1;
3.  
4.  
5. @Bean

1.     @primary
2. public SqlSessionFactory sqlSessionFactory1() throws Exception {
3. SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
4. factoryBean.setDataSource(ds1); // 使用titan数据源, 连接titan库
5.  
6. return factoryBean.getObject();
7.  
8. }
9.  
10. @Bean

1.     @primary
2. public SqlSessionTemplate sqlSessionTemplate1() throws Exception {
3. SqlSessionTemplate template = new SqlSessionTemplate(sqlSessionFactory1()); // 使用上面配置的Factory
4. return template;
5. }
6. }

经过上面的配置后，titan.mapper下的Mapper接口，都会使用titan数据源。同理可配第二个SqlSessionFactory:

1. @Configuration
2. @MapperScan(basePackages = {"other.mapper"}, sqlSessionFactoryRef = "sqlSessionFactory2")
3. public class MybatisDbBConfig {
4. @Autowired
5. @Qualifier("ds2")
6. private DataSource ds2;
7.  
8. @Bean
9. public SqlSessionFactory sqlSessionFactory2() throws Exception {
10. SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
11. factoryBean.setDataSource(ds2);
12.  
13.  
14. return factoryBean.getObject();
15.  
16. }
17.  
18. @Bean
19. public SqlSessionTemplate sqlSessionTemplate2() throws Exception {
20. SqlSessionTemplate template = new SqlSessionTemplate(sqlSessionFactory2());
21. return template;
22. }
23. }

完成这些配置后，假设有2个Mapper titan.mapper.UserMapper和other.mapper.RoleMapper，使用前者时会自动连接titan库，后者连接ds2库。

补：  上面的用@select @insert注解没有问题，

         如果要使用mapper.xml

        需要增加下面的配置：

       factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:path/**/*.xml"));