springboot jpa 多数据源

Spring Boot支持多数据源配置，可以使用JPA来访问多个数据库。

首先需要在application.properties文件中配置数据源：

# 数据源1
spring.datasource.url=jdbc:mysql://localhost:3306/test1
spring.datasource.username=root
spring.datasource.password=root

# 数据源2
spring.datasource.test2.url=jdbc:mysql://localhost:3306/test2
spring.datasource.test2.username=root
spring.datasource.test2.password=root

然后在配置类中配置多个数据源：

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
    entityManagerFactoryRef = "entityManagerFactory1",
    transactionManagerRef = "transactionManager1",
    basePackages = { "com.example.repository1" })
public class DataSource1Config {

    @Primary
    @Bean(name = "dataSource1")
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Primary
    @Bean(name = "entityManagerFactory1")
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(
        EntityManagerFactoryBuilder builder, @Qualifier("dataSource1") DataSource dataSource) {
        return builder
            .dataSource(dataSource)
            .packages("com.example.entity1")
            .persistenceUnit("dataSource1")
            .build();
    }

    @Primary
    @Bean(name = "transactionManager1")
    public PlatformTransactionManager transactionManager(
        @Qualifier("entityManagerFactory1") EntityManagerFactory entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory);
    }
}

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
    entityManagerFactoryRef = "entityManagerFactory2",
    transactionManagerRef = "transactionManager2",
    basePackages = { "com.example.repository2" })
public class DataSource2Config {

    @Bean(name = "dataSource2")
    @ConfigurationProperties(prefix = "spring.datasource.test2")
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "entityManagerFactory2")
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(
        EntityManagerFactoryBuilder builder, @Qualifier("dataSource2") DataSource dataSource) {
        return builder
            .dataSource(dataSource)
            .packages("com.example.entity2")
            .persistenceUnit("dataSource2")
            .build();
    }

    @Bean(name = "transactionManager2")
    public PlatformTransactionManager transactionManager(
        @Qualifier("entityManagerFactory2") EntityManagerFactory entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory);
    }
}

最后在服务类中指定使用哪个数据源：

@Service
@Transactional(transactionManager = "transactionManager1")
public class Service1 {
    @Autowired
    private Repository1 repository1;

    // ...
}

@Service
@Transactional(transactionManager = "transactionManager2")
public class Service2 {
    @Autowired
    private Repository2 repository2;

    // ...
}

以上就是使用Spring Boot和JPA实现多数据源的步骤。