@工厂豆类初级课程

Question

我的简化版本如下所示：

@Configuration
@EnableTransactionManagement
public class DatabaseDefaultConfig {

  @Bean
  @Primary
  public DataSource dataSourceDefault(DatabaseConfigurationHelper databaseConfigurationHelper) {
    return ...;
  }

  @Bean
  @Primary
  public SqlSessionFactoryBean sqlSessionFactoryBeanDefault(DatabaseConfigurationHelper databaseConfigurationHelper, @Value("${datasource.default.cacheEnabled}") boolean cacheEnabled) throws Exception {
    return ...;
  }

}

@Configuration
@EnableTransactionManagement
public class DatabaseMaintenanceConfig {

  @Bean
  public DataSource dataSourceMaintenance(DatabaseConfigurationHelper databaseConfigurationHelper) {
    return ...;
  }

  @Bean
  public SqlSessionFactoryBean sqlSessionFactoryBeanMaintenance(DatabaseConfigurationHelper databaseConfigurationHelper, @Value("${datasource.maintenance.cacheEnabled}") boolean cacheEnabled) throws Exception {
    return ...;
  }

}

类是非常相同的，其中一个使用@Primary。现在，让我们创建两个虚拟bean：

@Configuration
public class CommonDatabaseConfig {

  @Bean
  public AtomicInteger a(SqlSessionFactoryBean sqlSessionFactoryBean) {
    return new AtomicInteger();
  }

  @Bean
  public AtomicLong b(DataSource dataSource) {
    return new AtomicLong();
  }

}

虽然b运行良好，但a失败并声称找到了两个bean：

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

Description:

Parameter 0 of method a in sjngm.CommonDatabaseConfig required a single bean, but 2 were found:
    - &sqlSessionFactoryBeanDefault: defined by method 'sqlSessionFactoryBeanDefault' in class path resource [sjngm/DatabaseDefaultConfig.class]
    - &sqlSessionFactoryBeanMaintenance: defined by method 'sqlSessionFactoryBeanMaintenance' in class path resource [sjngm/DatabaseMaintenanceConfig.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

请注意，这两个bean都以&开头。读一读这个问题及其答案，就可以清楚地看出这是有意的。然而，这似乎破坏了应用@Primary，因为它在Spring的DefaultListableBeanFactory中失败了

protected boolean isPrimary(String beanName, Object beanInstance) {
    if (containsBeanDefinition(beanName)) {
        return getMergedLocalBeanDefinition(beanName).isPrimary();
    }
    BeanFactory parent = getParentBeanFactory();
    return (parent instanceof DefaultListableBeanFactory &&
            ((DefaultListableBeanFactory) parent).isPrimary(beanName, beanInstance));
}

第2行中的containsBeanDefinition()返回false，因为有符号。

我在这里做错什么了吗？我怎么才能解决这个问题？

这是Spring4.3.9(作为Spring 1.5.4的一部分)

Answer 1

它是在spring-framework PR 22711内部修复的。