org.springframework.beans.factory.config.SingletonBeanRegistry#registerSingleton ( )源码实例Demo

public static void main(String[] args) throws InterruptedException {
    // 创建 BeanFactory 容器
    AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
    // 创建一个外部 UserFactory 对象
    UserFactory userFactory = new DefaultUserFactory();
    SingletonBeanRegistry singletonBeanRegistry = applicationContext.getBeanFactory();
    // 注册外部单例对象
    singletonBeanRegistry.registerSingleton("userFactory", userFactory);
    // 启动 Spring 应用上下文
    applicationContext.refresh();

    // 通过依赖查找的方式来获取 UserFactory
    UserFactory userFactoryByLookup = applicationContext.getBean("userFactory", UserFactory.class);
    System.out.println("userFactory  == userFactoryByLookup : " + (userFactory == userFactoryByLookup));

    // 关闭 Spring 应用上下文
    applicationContext.close();
}
 

public static void registerSingleton(ApplicationContext applicationContext, String beanName, Object singletonObject) {

    AutowireCapableBeanFactory beanFactory = applicationContext.getAutowireCapableBeanFactory();
    if (!SingletonBeanRegistry.class.isAssignableFrom(beanFactory.getClass())) {
      throw new IllegalArgumentException(
          "ApplicationContext: " + applicationContext.getClass().toString()
              + " doesn't implements SingletonBeanRegistry, cannot register JMS connection at runtime");
    }

    SingletonBeanRegistry beanDefinitionRegistry = (SingletonBeanRegistry) beanFactory;
    beanDefinitionRegistry.registerSingleton(beanName, singletonObject);

  }
 

public static void registerSingleton(BeanDefinitionRegistry registry, String beanName, Object singletonObject) {

    if (!SingletonBeanRegistry.class.isAssignableFrom(registry.getClass())) {
      throw new IllegalArgumentException(
          "BeanDefinitionRegistry: " + registry.getClass().toString()
              + " doesn't implements SingletonBeanRegistry, cannot register JMS connection at runtime");
    }

    SingletonBeanRegistry beanDefinitionRegistry = (SingletonBeanRegistry) registry;
    beanDefinitionRegistry.registerSingleton(beanName, singletonObject);

  }