1.前言

刚更新了一篇SpringBoot整合mybatis。
精通Spring Boot:整合Mybatis多数据源
突然想mybatis虽然功能强大，但是对sql的要求还是算高的。Spring Data Jpa对于某些用户来说 ，还是个比较简单的选择。毕竟不用写较复杂的sql语句，于是就想，来一个SpringBoot+mybatis + jpa的大杂烩。

2.开始整合

说到底，多数据源整合其实就是要保证项目中有且仅有一个primaryDataSource，即主数据源，它是无可替代的。
先看application.yml 有多少个数据源就的配置多少个数据库链接

spring:
  ## multipart datasource configuration ##
  datasource:
    primary:
      jdbc-url: jdbc:mysql://localhost:3306/javashop
      username: root
      password: 123456
      driver-class-name: com.mysql.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource
    secondary:
      jdbc-url: jdbc:mysql://localhost:3306/test
      username: root
      password: 123456
      driver-class-name: com.mysql.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource
    master:
      jdbc-url: jdbc:mysql://localhost:3306/javashop
      username: root
      password: 123456
      driver-class-name: com.mysql.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource
    cluster:
      jdbc-url: jdbc:mysql://localhost:3306/test
      username: root
      password: 123456
      driver-class-name: com.mysql.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource

  jpa:
    hibernate:
      ddl-auto: update
      naming:
        physical-strategy: org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
    show-sql: true
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect

3.项目结构图

└─src
    ├─main
    │  ├─java
    │  │  └─com
    │  │      └─developlee
    │  │          └─multipartdatasource
    │  │              │  MultipartDatasourceApplication.java
    │  │              │  
    │  │              ├─config
    │  │              │  ├─jpa
    │  │              │  │      DataSourceConfig.java
    │  │              │  │      PrimaryDataSourceConfig.java
    │  │              │  │      SecondaryDataSourceConfig.java
    │  │              │  │      
    │  │              │  └─mybatis
    │  │              │          ClusterDataSourceConfig.java
    │  │              │          MasterDataSourceConfig.java
    │  │              │          
    │  │              ├─dao
    │  │              │  ├─jpa
    │  │              │  │  ├─primary
    │  │              │  │  │      UserRepository.java
    │  │              │  │  │      
    │  │              │  │  └─secondary
    │  │              │  │          CityRepository.java
    │  │              │  │          
    │  │              │  └─mybatis
    │  │              │      ├─cluster
    │  │              │      │      CityDao.java
    │  │              │      │      
    │  │              │      └─master
    │  │              │              UserDao.java
    │  │              │              
    │  │              ├─entity
    │  │              │  ├─jpa
    │  │              │  │  ├─primary
    │  │              │  │  │      UserEntity.java
    │  │              │  │  │      
    │  │              │  │  └─secondary
    │  │              │  │          CityEntity.java
    │  │              │  │          
    │  │              │  └─mybatis
    │  │              │      ├─cluster
    │  │              │      │      MybatisCityEntity.java
    │  │              │      │      
    │  │              │      └─master
    │  │              │              MybatisUserEntity.java
    │  │              │              
    │  │              └─service
    │  │                  │  CityService.java
    │  │                  │  UserService.java
    │  │                  │  
    │  │                  └─impl
    │  │                          CityServiceImpl.java
    │  │                          UserServiceImpl.java
    │  │                          
    │  └─resources
    │      │  application.yml
    │      │  
    │      ├─mapper
    │      │  ├─cluster
    │      │  │      city.xml
    │      │  │      
    │      │  └─master
    │      │          user.xml
    │      │          
    │      ├─static
    │      └─templates
    └─test
        └─java
            └─com
                └─developlee
                    └─multipartdatasource
                            MultipartDatasourceApplicationTests.java

从文件树可以看到，对每个数据源要操作的实体类和数据接口都进行隔离。

4. jpa数据源配置

@Configuration
public class DataSourceConfig {

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

    @Bean(name = "secondaryDataSource")
    @Qualifier("secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }

}

4.1 JPA-primary主数据源配置

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "primaryEntityManagerFactory",
        transactionManagerRef = "primaryTransactionManager",
        basePackages = { PrimaryDataSourceConfig.REPO_PACKAGE } // 设置 Repository 所在位置
        )
public class PrimaryDataSourceConfig {

    static final String REPO_PACKAGE = "com.developlee.multipartdatasource.dao.jpa.primary";
    static final String ENTITY_PACKAGE = "com.developlee.multipartdatasource.entity.jpa.primary";

    @Resource
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;

    @Resource
    private JpaProperties jpaProperties;

    @Primary
    @Bean(name = "primaryEntityManager")
    public EntityManager primaryEntityManager(EntityManagerFactoryBuilder builder) {
       return primaryEntityManagerFactory(builder).getObject().createEntityManager();
    }

    @Primary
    @Bean(name = "primaryEntityManagerFactory")
    public LocalContainerEntityManagerFactoryBean primaryEntityManagerFactory(EntityManagerFactoryBuilder builder) {
        return builder.dataSource(primaryDataSource)
                .properties(jpaProperties.getHibernateProperties(new HibernateSettings()))
                .persistenceUnit("primaryPersistenceUnit")
                .packages(ENTITY_PACKAGE)
                .build();
    }

    @Primary
    @Bean(name = "primaryTransactionManager")
    public PlatformTransactionManager primaryTransactionManager(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(primaryEntityManagerFactory(builder).getObject());
    }
}

jpa-secondary的从数据源与此类似。

4.2 mybatis-master数据源配置

@Configuration
@MapperScan(basePackages = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {
    // 精确到master目录和其他数据源隔离
    static final String PACKAGE = "com.developlee.multipartdatasource.dao.mybatis.master";
    static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";

    @Value("${spring.datasource.master.jdbc-url}")
    private String url;

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

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

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

    @Bean(name = "masterDataSource")
    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));
        return sessionFactory.getObject();
    }
}

mybatis-cluster数据源配置与此类似。

5.测试

说明下，业务逻辑代码就不贴了，可在我的github中找到。

@RunWith(SpringRunner.class)
@SpringBootTest
public class MultipartDatasourceApplicationTests {

    @Autowired
    UserServiceImpl userService;

    @Autowired
    CityServiceImpl cityService;

    @Test
    public void contextLoads() {
        UserEntity userEntity = new UserEntity();
        userEntity.setUsername("JPA-Lensen");
        userEntity.setPwd("123456");
        userEntity.setMobile("137****8661");

        CityEntity cityEntity = new CityEntity();
        cityEntity.setUserId(1024L);
        cityEntity.setDescription("JPA-Lensen-Desc");

        MybatisUserEntity mybatisUserEntity = new MybatisUserEntity();
        mybatisUserEntity.setUsername("Mybatis-Lensen");
        mybatisUserEntity.setPwd("654321");
        mybatisUserEntity.setMobile("137****1024");

        MybatisCityEntity mybatisCityEntity = new MybatisCityEntity();
        mybatisCityEntity.setDesc("MyBatis-Lensen-Desc");
        mybatisCityEntity.setUserId(2048L);
        mybatisCityEntity.setId(10L);

        userService.saveUserByJpa(userEntity);
        cityService.saveCityByJpa(cityEntity);
        userService.saveUserByMybatis(mybatisUserEntity);
        cityService.saveCityByMybatis(mybatisCityEntity);

    }

}

截图看看效果

看看数据库的数据
tb_user表

tb_city表

最后： 此项目代码可在我的github.com中找到。