在 Spring Boot 应用程序的多个数据库中未创建表

Question

我正在开发 Spring Boot 多租户应用程序。我已经配置了多个数据源，如下所示：

application.properties

spring.multitenancy.datasource1.url=jdbc:mysql://localhost:3306/db1
spring.multitenancy.datasource1.username=root
spring.multitenancy.datasource1.password=****
spring.multitenancy.datasource1.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update

spring.multitenancy.datasource2.url=jdbc:mysql://localhost:3306/db2
spring.multitenancy.datasource2.username=root
spring.multitenancy.datasource2.password=****
spring.multitenancy.datasource2.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update

spring.multitenancy.datasource3.url=jdbc:mysql://localhost:3306/db3
spring.multitenancy.datasource3.username=root
spring.multitenancy.datasource3.password=****
spring.multitenancy.datasource3.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update

DataSourceBasedMultiTenantConnectionProviderImpl.java

@Component
public class DataSourceBasedMultiTenantConnectionProviderImpl extends AbstractDataSourceBasedMultiTenantConnectionProviderImpl {

    private static final long serialVersionUID = 8168907057647334460L;
    private static final String DEFAULT_TENANT_ID = "tenant_1";

    @Autowired
    private DataSource dataSource1;

    @Autowired
    private DataSource dataSource2;

    @Autowired
    private DataSource dataSource3;

    private Map<String, DataSource> map;

    @PostConstruct
    public void load() {
        map = new HashMap<>();
        map.put("tenant_1", dataSource1);
        map.put("tenant_2", dataSource2);
        map.put("tenant_3", dataSource3);
    }

    @Override
    protected DataSource selectAnyDataSource() {
        return map.get(DEFAULT_TENANT_ID);
    }

    @Override
    protected DataSource selectDataSource(String tenantIdentifier) {
        return map.get(tenantIdentifier);
    }
}

多租户属性.java

@ConfigurationProperties("spring.multitenancy")
public class MultitenancyProperties {

    @NestedConfigurationProperty
    private DataSourceProperties datasource1;

    @NestedConfigurationProperty
    private DataSourceProperties datasource2;

    @NestedConfigurationProperty
    private DataSourceProperties datasource3;

    public DataSourceProperties getDatasource1() {
        return datasource1;
    }

    public void setDatasource1(DataSourceProperties datasource1) {
        this.datasource1 = datasource1;
    }

    public DataSourceProperties getDatasource2() {
        return datasource2;
    }

    public void setDatasource2(DataSourceProperties datasource2) {
        this.datasource2 = datasource2;
    }

    public DataSourceProperties getDatasource3() {
        return datasource3;
    }

    public void setDatasource3(DataSourceProperties datasource3) {
        this.datasource3 = datasource3;
    }
}

MultiTenancyJpaConfiguration.java

@Configuration
@EnableConfigurationProperties(JpaProperties.class)
public class MultiTenancyJpaConfiguration {

    @Autowired
    private DataSource dataSource;

    @Autowired
    private JpaProperties jpaProperties;

    @Autowired
    private MultiTenantConnectionProvider multiTenantConnectionProvider;

    @Autowired
    private CurrentTenantIdentifierResolver currentTenantIdentifierResolver;

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(EntityManagerFactoryBuilder builder) {
        Map<String, Object> hibernateProps = new LinkedHashMap<>();
        hibernateProps.putAll(jpaProperties.getHibernateProperties(dataSource));

        hibernateProps.put(Environment.MULTI_TENANT, MultiTenancyStrategy.DATABASE);
        hibernateProps.put(Environment.MULTI_TENANT_CONNECTION_PROVIDER, multiTenantConnectionProvider);
        hibernateProps.put(Environment.MULTI_TENANT_IDENTIFIER_RESOLVER, currentTenantIdentifierResolver);
        hibernateProps.put(Environment.DIALECT, "org.hibernate.dialect.MySQLDialect");

        return builder.dataSource(dataSource).packages(HotelEntity.class.getPackage().getName()).properties(hibernateProps).jta(false).build();
    }
}

应用程序启动器

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableConfigurationProperties(MultitenancyProperties.class)
public class Application {

    public static void main(String[] args) {
        ApplicationContext ctx = SpringApplication.run(Application.class, args);
    }
}

当我运行启动应用程序时，所有表都仅在第一个数据源中创建。
1) 如何在应用程序启动时在所有数据源中创建表？
2) 如何查看每个数据源打开/关闭的连接？
3) 有没有更好的方法来使用 Spring Boot 配置多租户应用程序以获得更好的性能？

Answer 1

正如@Alex 所说，您需要不同的 EntityManagers、TransactionManager 和 Datasources。这是我的做法

@Configuration
@EnableJpaRepositories(
    entityManagerFactoryRef = "dataSource1EntityManagerFactory",
    transactionManagerRef = "dataSource1TransactionManager",
    basePackageClasses = dataSource1Repository.class)
public class DataSource1Config extends SqlConfig{// Put all common code in base class SqlConfig. If not remove it

    @Bean
    @Primary
    public DataSource dataSource1() {
        //create dataSource using MultitenancyProperties::getDataSource1
    }

    @Primary
    @Bean(name = "dataSource1TransactionManager")
    PlatformTransactionManager dataSource1TransactionManager(EntityManagerFactory dataSource1EntityManagerFactory) {
        JpaTransactionManager txManager = new JpaTransactionManager();
        txManager.setEntityManagerFactory(dataSource1EntityManagerFactory);
        return txManager;
    }

    @Primary
    @Bean(name = "dataSource1EntityManagerFactory")
    LocalContainerEntityManagerFactoryBean dataSource1EntityManagerFactory() {
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource1());
        em.setPackagesToScan(dataSource1Repository.class.getPackage().getName(), dataSource1ModelClass.class.getPackage().getName());
        em.setPersistenceUnitName("dataSource1Db");

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(false);
        em.setJpaVendorAdapter(vendorAdapter);
        return em;
    }
}

您可以像这样创建另外两个类。请记住仅在数据源、事务管理器和实体管理器的一个实例上使用@Primary（不管哪一个）。再提醒一句，请确保 Repository 类位于所有三个数据库的不同包中。

Answer 2

尝试添加以下属性：

spring.jpa.generate-ddl=true

Answer 3

您需要 2 个不同的持久性工厂，而不是一个，每个都应该为不同的数据源生成不同的 EntityManager。此外，每个实体映射都应标记为仅与一个实体管理器一起使用。 在此处查看完整解决方案：

http://www.baeldung.com/spring-data-jpa-multiple-databases