Spring Boot，带有多个数据源的Spring Data JPA

Question

我正在尝试使用Spring Boot和Spring Data JPA将每个@Repositories连接到不同的DataSource。 我使用以下http://xantorohara.blogspot.com/2013/11/spring-boot-jdbc-with-multiple.html作为参考。 这是我正在尝试使用Spring Data JPA实现类似解决方案的代码。

CustomerDbConfig.java （第一个数据源连接）

@Configuration
@EnableJpaRepositories(
        entityManagerFactoryRef = "orderEntityManager",
        transactionManagerRef = "orderTransactionManager",
        basePackages = {"com.mm.repository.customer"})
public class CustomerDbConfig {

    @Bean(name = "customerEntityManager")
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(){
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource());
        em.setPackagesToScan(new String[] {"com.mm.domain.customer"});

        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(additionalJpaProperties());
        em.setPersistenceUnitName("customerPersistence");
        em.setPackagesToScan("com.mm.domain.customer");

        return em;
    }

    Properties additionalJpaProperties(){
        Properties properties = new Properties();
        properties.setProperty("hibernate.hbm2ddl.auto", "create-drop");
        properties.setProperty("hibernate.dialect", "org.hibernate.dialect.H2Dialect");
        properties.setProperty("hibernate.show_sql", "true");

        return properties;
    }

    @Bean
    public DataSource dataSource(){
        return DataSourceBuilder.create()
                .url("jdbc:h2:mem:customer:H2")
                .driverClassName("org.h2.Driver")
                .username("sa")
                .password("")
                .build();
    }   

    @Bean(name = "customerTransactionManager")
    public PlatformTransactionManager transactionManager(EntityManagerFactory emf){
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(emf);

        return transactionManager;
    }
}

CustomerDbConfig.java （第二个数据源）

@Configuration
@EnableJpaRepositories(
        entityManagerFactoryRef = "orderEntityManager",
        transactionManagerRef = "orderTransactionManager",
        basePackages = {"com.mm.repository.customer"})
public class CustomerDbConfig {

    @Bean(name = "customerEntityManager")
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(){
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource());
        em.setPackagesToScan(new String[] {"com.mm.domain.customer"});

        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(additionalJpaProperties());
        em.setPersistenceUnitName("customerPersistence");
        em.setPackagesToScan("com.mm.domain.customer");

        return em;
    }

    Properties additionalJpaProperties(){
        Properties properties = new Properties();
        properties.setProperty("hibernate.hbm2ddl.auto", "create-drop");
        properties.setProperty("hibernate.dialect", "org.hibernate.dialect.H2Dialect");
        properties.setProperty("hibernate.show_sql", "true");

        return properties;
    }

    @Bean
    public DataSource dataSource(){
        return DataSourceBuilder.create()
                .url("jdbc:h2:mem:customer:H2")
                .driverClassName("org.h2.Driver")
                .username("sa")
                .password("")
                .build();
    }   

    @Bean(name = "customerTransactionManager")
    public PlatformTransactionManager transactionManager(EntityManagerFactory emf){
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(emf);

        return transactionManager;
    }
}

Customer.java （模型）

@Entity
@Table(name = "customer")
@Data
@EqualsAndHashCode(exclude = {"id"})
public class Customer {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    @Column(name = "name", nullable = false)
    private String name;

    @Column(name = "age", nullable = false)
    private Integer age;

....

Order.java （模型）

@Entity
@Table(name = "order")
@Data
@EqualsAndHashCode(exclude = {"id"})
public class Order {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    @Column(name = "code", nullable = false)
    private Integer code;

    @Column(name = "quality", nullable = false)
    private Integer quality;

...

CustomerRepository.java

public interface CustomerRepository extends JpaRepository<Customer, Integer>{

}

OrderRepository.java

public interface OrderRepository extends JpaRepository<Order, Integer> {

}

最后， Application.java

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application extends SpringApplication{

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

        @Bean
        public ServletRegistrationBean h2Console() {
            ServletRegistrationBean reg = new ServletRegistrationBean(new WebServlet(), "/console/*");
            reg.setLoadOnStartup(1);
            return reg;
        }
}

在启动过程中会引发以下异常 ：

-10-10 15:45:24.757 ERROR 1549 --- [           main] o.s.boot.SpringApplication               : Application startup failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'customerTransactionManager' defined in class path resource [com/mm/boot/multidb/CustomerConfig.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [javax.persistence.EntityManagerFactory]: : No qualifying bean of type [javax.persistence.EntityManagerFactory] is defined: expected single matching bean but found 2: customerEntityManager,orderEntityManager; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [javax.persistence.EntityManagerFactory] is defined: expected single matching bean but found 2: customerEntityManager,orderEntityManager
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:747)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:462)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1095)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:990)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:706)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:109)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
    at com.mm.boot.multidb.Application.main(Application.java:17)
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [javax.persistence.EntityManagerFactory] is defined: expected single matching bean but found 2: customerEntityManager,orderEntityManager
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:974)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:862)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:811)
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:739)
    ... 18 common frames omitted

Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'customerTransactionManager' defined in class path resource [com/mm/boot/multidb/CustomerConfig.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [javax.persistence.EntityManagerFactory]: : No qualifying bean of type [javax.persistence.EntityManagerFactory] is defined: expected single matching bean but found 2: customerEntityManager,orderEntityManager; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [javax.persistence.EntityManagerFactory] is defined: expected single matching bean but found 2: customerEntityManager,orderEntityManager
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:747)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:462)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1095)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:990)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:706)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:109)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
    at com.mm.boot.multidb.Application.main(Application.java:17)
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [javax.persistence.EntityManagerFactory] is defined: expected single matching bean but found 2: customerEntityManager,orderEntityManager
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:974)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:862)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:811)
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:739)
    ... 18 more

该示例的完整代码可以在GitHub（ https://github.com/tonym2105/samples/tree/master/boot-multidb-sample ）上找到。

预先感谢您的帮助。

Answer 1

通过使用@EnableAutoConfiguration和application.properties，还有另一种具有多个数据源的方法。

基本上，将多个dataSource配置信息放在application.properties上，并通过@EnableAutoConfiguration自动为第一个dataSource生成默认设置（dataSource和EntityManagerFactory）。 但是对于下一个dataSource，请通过属性文件中的信息手动创建dataSource，entityManagerFactory和transactionManager。

下面是我设置两个数据源的示例。 第一个数据源由@EnableAutoConfiguration设置，只能分配给一个配置，不能分配给多个。 然后将通过DataSourceTransactionManager生成“ transactionManager”，该外观看起来是由注释生成的默认transactionManager。 但是，我已经看到，仅对于默认的DataSourceTransactionManager以及在有多个事务管理器的情况下，计划线程池中的线程上的事务并未开始出现问题。 因此，我还通过JpaTransactionManager手动为第一个数据源创建了transactionManager，并分配了'transactionManager'bean名称和默认的entityManagerFactory。 用于第一个数据源的JpaTransactionManager确实可以解决ScheduledThreadPool中线程上的奇怪事务问题。

Spring Boot 1.3.0.RELEASE的更新

我发现我以前使用@EnableAutoConfiguration的默认dataSource配置在使用Spring Boot 1.3版本查找entityManagerFactory时遇到问题。 引入我自己的transactionManager后，@ EnableAutoConfiguration可能不会生成默认的entityManagerFactory。 所以现在我自己创建了entityManagerFactory。 因此，我不需要使用@EntityScan。 因此，看起来我通过@EnableAutoConfiguration获得的安装越来越少。

第二个数据源是在没有@EnableAutoConfiguration的情况下设置的，并通过手动方式创建了“ anotherTransactionManager”。

由于从PlatformTransactionManager扩展了多个transactionManager，因此我们应在每个@Transactional批注中指定使用哪个transactionManager

默认存储库配置

@Configuration
@EnableTransactionManagement
@EnableAutoConfiguration
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactory",
        transactionManagerRef = "transactionManager",
        basePackages = {"com.mysource.repository"})
public class RepositoryConfig {
    @Autowired
    JpaVendorAdapter jpaVendorAdapter;

    @Autowired
    DataSource dataSource;

    @Bean(name = "entityManager")
    public EntityManager entityManager() {
        return entityManagerFactory().createEntityManager();
    }

    @Primary
    @Bean(name = "entityManagerFactory")
    public EntityManagerFactory entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
        emf.setDataSource(dataSource);
        emf.setJpaVendorAdapter(jpaVendorAdapter);
        emf.setPackagesToScan("com.mysource.model");
        emf.setPersistenceUnitName("default");   // <- giving 'default' as name
        emf.afterPropertiesSet();
        return emf.getObject();
    }

    @Bean(name = "transactionManager")
    public PlatformTransactionManager transactionManager() {
        JpaTransactionManager tm = new JpaTransactionManager();
        tm.setEntityManagerFactory(entityManagerFactory());
        return tm;
    }
}

另一个存储库配置

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "anotherEntityManagerFactory",
        transactionManagerRef = "anotherTransactionManager",
        basePackages = {"com.mysource.anothersource.repository"})
public class AnotherRepositoryConfig {
    @Autowired
    JpaVendorAdapter jpaVendorAdapter;

    @Value("${another.datasource.url}")
    private String databaseUrl;

    @Value("${another.datasource.username}")
    private String username;

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

    @Value("${another.dataource.driverClassName}")
    private String driverClassName;

    @Value("${another.datasource.hibernate.dialect}")
    private String dialect;

    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource(databaseUrl, username, password);
        dataSource.setDriverClassName(driverClassName);
        return dataSource;
    }

    @Bean(name = "anotherEntityManager")
    public EntityManager entityManager() {
        return entityManagerFactory().createEntityManager();
    }

    @Bean(name = "anotherEntityManagerFactory")
    public EntityManagerFactory entityManagerFactory() {
        Properties properties = new Properties();
        properties.setProperty("hibernate.dialect", dialect);

        LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
        emf.setDataSource(dataSource());
        emf.setJpaVendorAdapter(jpaVendorAdapter);
        emf.setPackagesToScan("com.mysource.anothersource.model");   // <- package for entities
        emf.setPersistenceUnitName("anotherPersistenceUnit");
        emf.setJpaProperties(properties);
        emf.afterPropertiesSet();
        return emf.getObject();
    }

    @Bean(name = "anotherTransactionManager")
    public PlatformTransactionManager transactionManager() {
        return new JpaTransactionManager(entityManagerFactory());
    }
}

application.properties

# database configuration
spring.datasource.url=jdbc:h2:file:~/main-source;AUTO_SERVER=TRUE
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.continueOnError=true
spring.datasource.initialize=false

# another database configuration
another.datasource.url=jdbc:sqlserver://localhost:1433;DatabaseName=another;
another.datasource.username=username
another.datasource.password=
another.datasource.hibernate.dialect=org.hibernate.dialect.SQLServer2008Dialect 
another.datasource.driverClassName=com.microsoft.sqlserver.jdbc.SQLServerDriver

为@Transactional注释选择适当的transactionManager

第一数据源服务

@Service("mainService")
@Transactional("transactionManager")
public class DefaultDataSourceServiceImpl implements DefaultDataSourceService       
{

   //

}

为另一个数据源提供服务

@Service("anotherService")
@Transactional("anotherTransactionManager")
public class AnotherDataSourceServiceImpl implements AnotherDataSourceService 
{

   //

}

Answer 2

这是我的解决方案。 基于spring-boot.1.2.5.RELEASE。

application.properties

first.datasource.driver-class-name=com.mysql.jdbc.Driver
first.datasource.url=jdbc:mysql://127.0.0.1:3306/test
first.datasource.username=
first.datasource.password=
first.datasource.validation-query=select 1

second.datasource.driver-class-name=com.mysql.jdbc.Driver
second.datasource.url=jdbc:mysql://127.0.0.1:3306/test2
second.datasource.username=
second.datasource.password=
second.datasource.validation-query=select 1

DataSourceConfig.java

@Configuration
public class DataSourceConfig {
    @Bean
    @Primary
    @ConfigurationProperties(prefix="first.datasource")
    public DataSource firstDataSource() {
        DataSource ds =  DataSourceBuilder.create().build();
        return ds;
    }

    @Bean
    @ConfigurationProperties(prefix="second.datasource")
    public DataSource secondDataSource() {
        DataSource ds =  DataSourceBuilder.create().build();
        return ds;
    }
}

Answer 3

我检查了您在GitHub上提供的源代码。 配置中存在一些错误/错别字。

在CustomerDbConfig / OrderDbConfig中，您应该引用customerEntityManager，并且程序包应指向现有程序包：

@Configuration
@EnableJpaRepositories(
    entityManagerFactoryRef = "customerEntityManager",
    transactionManagerRef = "customerTransactionManager",
    basePackages = {"com.mm.boot.multidb.repository.customer"})
public class CustomerDbConfig {

在customerEntityManager和orderEntityManager中扫描的软件包都没有指向正确的软件包：

em.setPackagesToScan("com.mm.boot.multidb.model.customer");

同样，正确的EntityManagerFactory的注入也不起作用。 它应该是：

@Bean(name = "customerTransactionManager")
public PlatformTransactionManager transactionManager(EntityManagerFactory customerEntityManager){

}

以上是导致问题和异常的原因。 在使用@Bean方法提供名称时，请确保已注入正确的EMF。

我做的最后一件事是禁用JpaRepositories的自动配置：

@EnableAutoConfiguration(exclude = JpaRepositoriesAutoConfiguration.class)

利用所有修复程序，应用程序将按您预期的那样启动！

Answer 4

多亏了Steve Park和Rafal Borowiec的回答，我的代码才能正常工作，但是，我遇到了一个问题：DriverManagerDataSource是一个“简单”的实现，没有提供ConnectionPool （请检查http://docs.spring.io/ spring / docs / current / javadoc-api / org / springframework / jdbc / datasource / DriverManagerDataSource.html ）。

因此，我替换了将secondDB的DataSource返回到的函数。

public DataSource <secondaryDB>DataSource() {
    // use DataSourceBuilder and NOT DriverManagerDataSource 
    // as this would NOT give you ConnectionPool
    DataSourceBuilder dataSourceBuilder = DataSourceBuilder.create();
    dataSourceBuilder.url(databaseUrl);
    dataSourceBuilder.username(username);
    dataSourceBuilder.password(password);
    dataSourceBuilder.driverClassName(driverClassName);
    return dataSourceBuilder.build();
}

另外，如果您不需要这样的EntityManager ，则可以删除EntityManager entityManager()和@Bean批注。

另外，您可能需要删除配置类的basePackages批注：使用factoryBean.setPackagesToScan()对其进行维护就足够了。

Answer 5

我已经在Spring Boot JPA Multiple Data Sources Example上写了一篇完整的文章。 在本文中，我们将学习如何在典型的Spring Boot Web应用程序中配置多个数据源并连接到多个数据库。 我们将使用Spring Boot 2.0.5，JPA，Hibernate 5，Thymeleaf和H2数据库来构建一个简单的Spring Boot多个数据源Web应用程序。

Answer 6

不知道为什么，但是可以。 两种配置相同，只是将xxx更改为您的名字。

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
    entityManagerFactoryRef = "xxxEntityManager",
    transactionManagerRef = "xxxTransactionManager",
    basePackages = {"aaa.xxx"})
 public class RepositoryConfig {
@Autowired
private Environment env;

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

@Bean
public LocalContainerEntityManagerFactoryBean xxxEntityManager() {
    LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
    em.setDataSource(xxxDataSource());
    em.setPackagesToScan(new String[] {"aaa.xxx"});

    HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    em.setJpaVendorAdapter(vendorAdapter);
    HashMap<String, Object> properties = new HashMap<String, Object>();
    properties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
    properties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
    properties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
    em.setJpaPropertyMap(properties);

    return em;
}

@Bean(name = "xxxTransactionManager")
public PlatformTransactionManager xxxTransactionManager() {
    JpaTransactionManager tm = new JpaTransactionManager();
    tm.setEntityManagerFactory(xxxEntityManager().getObject());
    return tm;
}

}