public class UserController implements InitializingBean{

  private UserService userService;

  public UserService getUserService() {
    return userService;
  }

  public void setUserService(UserService userService) {
    this.userService = userService;
  }

  @Override
  public void afterPropertiesSet() throws Exception {
    System.out.println("我是动态注册的你,不是容器启动的时候注册的你");
  }

  public String toAction(String content){
    return "-->" + userService.doService(content);
  }
}

public class SpringContextUtil {
  private static ApplicationContext applicationContext;
  //获取上下文
  public static ApplicationContext getApplicationContext() {
    return applicationContext;
  }
  //设置上下文
  public static void setApplicationContext(ApplicationContext applicationContext) {
    SpringContextUtil.applicationContext = applicationContext;
  }
  //通过名字获取上下文中的bean
  public static Object getBean(String name){
    return applicationContext.getBean(name);
  }
  //通过类型获取上下文中的bean
  public static Object getBean(Class<?> requiredType){
    return applicationContext.getBean(requiredType);
  }
}

@SpringBootApplication
public class HelloApplication {

  public static void main(String[] args) {
    ApplicationContext app = SpringApplication.run(HelloApplication.class, args);
    SpringContextUtil.setApplicationContext(app);
  }  
}

@GetMapping("/bean")
public String registerBean() {
  //将applicationContext转换为ConfigurableApplicationContext
  ConfigurableApplicationContext configurableApplicationContext = (ConfigurableApplicationContext) SpringContextUtil.getApplicationContext();

  // 获取bean工厂并转换为DefaultListableBeanFactory
  DefaultListableBeanFactory defaultListableBeanFactory = (DefaultListableBeanFactory) configurableApplicationContext.getBeanFactory();

  // 通过BeanDefinitionBuilder创建bean定义
  BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition(UserController.class);
    
  // 设置属性userService,此属性引用已经定义的bean:userService,这里userService已经被spring容器管理了.
  beanDefinitionBuilder.addPropertyReference("userService", "userService");

  // 注册bean
  defaultListableBeanFactory.registerBeanDefinition("userController", beanDefinitionBuilder.getRawBeanDefinition());


  UserController userController = (UserController) SpringContextUtil.getBean("userController");

  return userController.toAction("动态注册生成调用");

   //删除bean.
  //defaultListableBeanFactory.removeBeanDefinition("testService");
}