Spring Boot，Spring Data JPA，带有多个DataSources

5 回答

• 6

  通过使用@EnableAutoConfiguration和application.properties，还有另一种方法可以拥有多个dataSource .

  基本上在application.properties上放置多个dataSource配置信息，并通过@EnableAutoConfiguration自动为第一个dataSource生成默认设置（dataSource和entityManagerFactory） . 但对于下一个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dataSource的示例 . 第一个dataSource由@EnableAutoConfiguration设置，只能为一个配置而不是多个配置 . 这将由 DataSourceTransactionManager 生成'transactionManager'，它看起来是由注释生成的默认transactionManager . 但是，我已经看到事务没有从调度线程池中的线程开始问题仅针对默认的DataSourceTransactionManager以及有多个事务管理器时 . 所以我也通过 JpaTransactionManager 为第一个dataSource手动创建了事务管理器，并分配了'transactionManager' bean名称和默认的entityManagerFactory . 第一个dataSource的JpaTransactionManager肯定会解决来自ScheduledThreadPool的线程上的奇怪事务问题 .

  Update for Spring Boot 1.3.0.RELEASE

  我发现我之前使用@EnableAutoConfiguration配置的默认dataSource在查找带有Spring Boot 1.3版本的entityManagerFactory时遇到了问题 . 在我介绍自己的transactionManager之后，可能默认的entityManagerFactory不是由@EnableAutoConfiguration生成的 . 所以现在我自己创建entityManagerFactory . 所以我不需要使用@EntityScan . 因此看起来我越来越多地通过@EnableAutoConfiguration进行设置了 .

  第二个dataSource在没有@EnableAutoConfiguration的情况下设置，并通过手动方式创建“anotherTransactionManager” .

  由于从PlatformTransactionManager扩展了多个transactionManager，我们应该指定在每个@Transactional注释上使用哪个transactionManager

  Default Repository Config

  @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;
      }
  }
  

  Another Repository Config

  @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

  Service for first datasource

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

  Service for another datasource

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

  回复于 2024-04-29T15:28:41+08:00
• 35

  我检查了你在GitHub上提供的源代码 . 配置中存在多个错误/拼写错误 .

  在CustomerDbConfig / OrderDbConfig中，您应该引用customerEntityManager，并且包应该指向现有的包：

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

  要在customerEntityManager和orderEntityManager中扫描的包都没有指向正确的包：

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

  注入适当的EntityManagerFactory也不起作用 . 它应该是：

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

  以上是导致问题和例外 . 在@Bean方法中提供名称时，您确定可以注入适当的EMF .

  我做的最后一件事是禁用自动配置JpaRepositories：

  @EnableAutoConfiguration(exclude = JpaRepositoriesAutoConfiguration.class)
  

  通过所有修复程序，应用程序就像您预期的那样启动！

  回复于 2024-04-29T15:28:41+08:00
• 1

  感谢Steve Park和Rafal Borowiec的答案我得到了我的代码，但是，我有一个问题：DriverManagerDataSource是一个"simple"实现并且 NOT give you a ConnectionPool （检查http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/jdbc/datasource/DriverManagerDataSource.html） .

  因此，我替换了为 secondDB 返回 DataSource 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();
  }
  

  此外，如果您不需要 EntityManager ，则可以同时删除 entityManager() 和 @Bean 注释 .

  另外，您可能希望删除配置类的basePackages注释：使用 factoryBean.setPackagesToScan() 调用来维护它是足够的 .

  回复于 2024-04-29T15:28:41+08:00
• -2

  不知道为什么，但它的确有效 . 两个配置相同，只需将xxx更改为您的名字即可 .

  @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;
  }
  

  }

  回复于 2024-04-29T15:28:41+08:00
• 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;
      }
  }
  

  回复于 2024-04-29T15:28:41+08:00