springboot 多数据源

Spring Boot支持多数据源，可以使用多个数据库进行开发。以下是实现多数据源的步骤：

1. 配置多个数据源

在application.properties文件中配置多个数据源，如：

spring.datasource.url=jdbc:mysql://localhost:3306/db1
spring.datasource.username=root
spring.datasource.password=123456

db2.datasource.url=jdbc:mysql://localhost:3306/db2
db2.datasource.username=root
db2.datasource.password=123456

2. 创建多个数据源

使用@Configuration注解创建多个数据源。如下：

@Configuration
public class DataSourceConfig {

    @Primary
    @Bean(name = "db1DataSource")
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource db1DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "db2DataSource")
    @ConfigurationProperties(prefix = "db2.datasource")
    public DataSource db2DataSource() {
        return DataSourceBuilder.create().build();
    }
}

3. 配置数据源的事务管理器

在每个数据源上配置事务管理器。如下：

@Configuration
@EnableTransactionManagement
public class TransactionConfig {

    @Bean(name = "db1TransactionManager")
    public PlatformTransactionManager db1TransactionManager(@Qualifier("db1DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "db2TransactionManager")
    public PlatformTransactionManager db2TransactionManager(@Qualifier("db2DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

4. 在@Repository中使用指定的数据源

在@Repository中指定使用哪个数据源。如下：

@Repository
public class UserRepository {

    @Autowired
    @Qualifier("db1DataSource")
    private DataSource db1DataSource;

    @Autowired
    @Qualifier("db2DataSource")
    private DataSource db2DataSource;

    @Autowired
    @Qualifier("db1TransactionManager")
    private PlatformTransactionManager db1TransactionManager;

    @Autowired
    @Qualifier("db2TransactionManager")
    private PlatformTransactionManager db2TransactionManager;

    @PersistenceContext(unitName = "db1")
    private EntityManager db1EntityManager;

    @PersistenceContext(unitName = "db2")
    private EntityManager db2EntityManager;

    @Transactional(transactionManager = "db1TransactionManager", propagation = Propagation.REQUIRED, rollbackFor = Exception.class)
    public void addUser(User user) {
        EntityManager entityManager = db1EntityManager;
        // ...
    }

    @Transactional(transactionManager = "db2TransactionManager", propagation = Propagation.REQUIRED, rollbackFor = Exception.class)
    public void addUser2(User user) {
        EntityManager entityManager = db2EntityManager;
        // ...
    }
}

以上是实现Spring Boot多数据源的步骤，可以根据具体需求进行配置和调整。