我的简化版本如下：
@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 ...;
}
}
这些类非常相似，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工作正常，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，两个bean都以&开头。阅读this question及其答案后，很明显这是有意的。然而，这似乎打破了应用@Primary，因为它在Spring DefaultListableBeanFactory的这个区域失败了：
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));
}
containsBeanDefinition()会返回false。
现在：我在这里做错了吗？我该如何解决这个问题？
这是Spring 4.3.9（作为Spring-Boot 1.5.4的一部分）