mysql - @Qualifier 不能在 Spring Boot 中使用多个 DataSource bean

Question

我在这里尝试使用四个 JPA 实体管理器为 spring boot 应用程序设置四个 MySQL 数据源。我是 spring 和 spring boot 的新手。我在谷歌上搜索了这个以获得线索，但结果非常困惑，有大量的配置方法(但不是用于处理多数据源)，我不确定要遵循什么。最后，我试图为每个 MySQL 数据源设置四个独立的实体管理器，并在事务中单独使用它们。

application.properties

# Database Properties
db.driver: com.mysql.jdbc.Driver
db.urlHotelPos: jdbc:mysql://localhost:3306/hotelwebpos
db.urlHotelFinance: jdbc:mysql://localhost:3306/hotelfinance
db.urlHotelInventory: jdbc:mysql://localhost:3306/hotelinventory
db.urlReservation: jdbc:mysql://localhost:3306/reservation
db.username: user
db.password: passwd

# Hibernate Properties
hibernate.dialect: org.hibernate.dialect.MySQL5Dialect
hibernate.show_sql: true
hibernate.hbm2ddl.auto: update
entitymanager.packagesToScan: com.test.poswebservice.model.*

DBconfigs.java

@Configuration
@EnableTransactionManagement
public class DBconfigs {

    @Bean
    public DataSource dataSourceHotelPos() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("db.driver"));
        dataSource.setUrl(env.getProperty("db.urlHotelPos"));
        dataSource.setUsername(env.getProperty("db.username"));
        dataSource.setPassword(env.getProperty("db.password"));
        return dataSource;
    }

    @Bean
    public DataSource dataSourceHotelFinance() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("db.driver"));
        dataSource.setUrl(env.getProperty("db.urlHotelFinance"));
        dataSource.setUsername(env.getProperty("db.username"));
        dataSource.setPassword(env.getProperty("db.password"));
        return dataSource;
    }

    @Bean
    public DataSource dataSourceHotelInventory() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("db.driver"));
        dataSource.setUrl(env.getProperty("db.urlHotelInventory"));
        dataSource.setUsername(env.getProperty("db.username"));
        dataSource.setPassword(env.getProperty("db.password"));
        return dataSource;
    }

    @Bean
    public DataSource dataSourceReservation() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("db.driver"));
        dataSource.setUrl(env.getProperty("db.urlReservation"));
        dataSource.setUsername(env.getProperty("db.username"));
        dataSource.setPassword(env.getProperty("db.password"));
        return dataSource;
    }

    @Bean
    @Qualifier("dataSourceHotelPos")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryHotelPos() {
        LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();

        entityManagerFactory.setDataSource(dataSourceHotelPos());

        entityManagerFactory.setPackagesToScan(env.getProperty("entitymanager.packagesToScan"));

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        entityManagerFactory.setJpaVendorAdapter(vendorAdapter);

        Properties additionalProperties = new Properties();
        additionalProperties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
        additionalProperties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
        additionalProperties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
        entityManagerFactory.setJpaProperties(additionalProperties);

        return entityManagerFactory;
    }

    @Bean
    @Qualifier("dataSourceHotelFinance")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryHotelFinance() {
        LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();

        entityManagerFactory.setDataSource(dataSourceHotelFinance());

        entityManagerFactory.setPackagesToScan(env.getProperty("entitymanager.packagesToScan"));

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        entityManagerFactory.setJpaVendorAdapter(vendorAdapter);

        Properties additionalProperties = new Properties();
        additionalProperties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
        additionalProperties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
        additionalProperties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
        entityManagerFactory.setJpaProperties(additionalProperties);

        return entityManagerFactory;
    }

    @Bean
    @Qualifier("dataSourceHotelInventory")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryHotelInventory(){
        LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();

        entityManagerFactory.setDataSource(dataSourceHotelInventory());

        entityManagerFactory.setPackagesToScan(env.getProperty("entitymanager.packagesToScan"));

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        entityManagerFactory.setJpaVendorAdapter(vendorAdapter);

        Properties additionalProperties = new Properties();
        additionalProperties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
        additionalProperties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
        additionalProperties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
        entityManagerFactory.setJpaProperties(additionalProperties);

        return entityManagerFactory;
    }

    @Bean
    @Qualifier("dataSourceReservation")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryReservation() {
        LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();

        entityManagerFactory.setDataSource(dataSourceReservation());

        entityManagerFactory.setPackagesToScan(env.getProperty("entitymanager.packagesToScan"));

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        entityManagerFactory.setJpaVendorAdapter(vendorAdapter);

        Properties additionalProperties = new Properties();
        additionalProperties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
        additionalProperties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
        additionalProperties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
        entityManagerFactory.setJpaProperties(additionalProperties);

        return entityManagerFactory;
    }

    @Bean
    @Qualifier("entityManagerFactoryHotelPos")
    public JpaTransactionManager transactionManagerHotelPos() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactoryHotelPos().getObject());
        return transactionManager;
    }

    @Bean
    @Qualifier("entityManagerFactoryHotelFinance")
    public JpaTransactionManager transactionManagerHotelFinance() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactoryHotelFinance().getObject());
        return transactionManager;
    }

    @Bean
    @Qualifier("entityManagerFactoryHotelInventory")
    public JpaTransactionManager transactionManagerHotelInventory() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactoryHotelInventory().getObject());
        return transactionManager;
    }

    @Bean
    @Qualifier("entityManagerFactoryReservation")
    public JpaTransactionManager transactionManagerReservation() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactoryReservation().getObject());
        return transactionManager;
    }

    @Bean
    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
        return new PersistenceExceptionTranslationPostProcessor();
    }

    @Autowired
    private Environment env;
}

输出>>

***************************
APPLICATION FAILED TO START
***************************

Description:

Method entityManagerFactoryHotelPos in com.test.poswebservice.configs.DBconfigs required a single bean, but 4 were found:
    - dataSourceHotelPos: defined by method 'dataSourceHotelPos' in class path resource [com/test/poswebservice/configs/DBconfigs.class]
    - dataSourceHotelFinance: defined by method 'dataSourceHotelFinance' in class path resource [com/test/poswebservice/configs/DBconfigs.class]
    - dataSourceHotelInventory: defined by method 'dataSourceHotelInventory' in class path resource [com/test/poswebservice/configs/DBconfigs.class]
    - dataSourceReservation: defined by method 'dataSourceReservation' in class path resource [com/test/poswebservice/configs/DBconfigs.class]


Action:

Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed

@Qualifier 注释应该可以避免这个问题，但在这里它以某种方式不起作用。我在这里做错了什么？请有人帮助我，这几乎要了我的命:-(任何帮助将不胜感激。

谢谢。

Answer 1

在我的设置中，它是这样工作的:

1. 从您的 EMF bean 中删除 @Qualifier
2. 在每个 EMF Bean 上添加:@DependsOn({"dataSource"}) 以及正确的 DataSource
3. 确实制作了 DataSource 之一 @Primary