详解基于Spring Boot与Spring Data JPA的多数据源配置

由于项目需要，最近研究了一下基于Spring Boot与spring Data JPA的多数据源配置问题。以下是传统的单数据源配置代码。这里使用的是Spring的Annotation在代码内部直接配置的方式，没有使用任何XML文件。

@Configuration @EnableJpaRepositories(basePackages = "org.lyndon.repository") @EnableTransactionManagement @PropertySource("classpath:application.properties") public class JpaConfig {      private static final String DATABASE_DRIVER = "db.driver";   private static final String DATABASE_URL = "db.url";   private static final String DATABASE_USER = "db.user";   private static final String DATABASE_PASSWord = "db.password";   private static final String PACKAGES_TO_SCAN = "packages.to.scan";   private static final String HIBERNATE_DIALECT = "hibernate.dialect";   private static final String HIBERNATE_SHOW_sql = "hibernate.show.sql";      @Resource   private Environment env;      @Bean   public DataSource dataSource() {     DruidDataSource source = new DruidDataSource();     source.setDriverClassName(env.getRequiredProperty(DATABASE_DRIVER));     source.setUrl(env.getRequiredProperty(DATABASE_URL));     source.setUsername(env.getRequiredProperty(DATABASE_USER));     source.setPassword(env.getRequiredProperty(DATABASE_PASSWORD));     return source;   }      @Bean   public LocalContainerEntityManagerFactoryBean entityManagerFactory() {     LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();     factory.setDataSource(dataSource());     factory.setPersistenceProviderClass(HibernatePersistenceProvider.class);     factory.setPackagesToScan(env.getRequiredProperty(PACKAGES_TO_SCAN));     factory.setJpaProperties(hibernateProperties());     factory.afterPropertiesSet();     return factory;   }      @Bean   public PlatfORMTransactionManager transactionManager() {     JpaTransactionManager manager = new JpaTransactionManager();     manager.setEntityManagerFactory(entityManagerFactory().getObject());     return manager;   }      @Bean   public HibernateExceptionTranslator hibernateExceptionTranslator() {     return new HibernateExceptionTranslator();   }      private Properties hibernateProperties() {     Properties properties = new Properties();     properties.put(HIBERNATE_DIALECT, env.getRequiredProperty(HIBERNATE_DIALECT));     properties.put(HIBERNATE_SHOW_SQL, env.getRequiredProperty(HIBERNATE_SHOW_SQL));     return properties;   }    }