手动注入bean

一、工具类

public class SpringCtxUtil implements ApplicationContextAware  {

	private static ApplicationContext applicationContext;
	private static DefaultListableBeanFactory defaultListableBeanFactory;


	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		AnycloudApplication.applicationContext = applicationContext;
		defaultListableBeanFactory = (DefaultListableBeanFactory)applicationContext.getAutowireCapableBeanFactory();
	}

	public static <T> T getBean(Class<T> clazz) {
		BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition(clazz);
		String className = clazz.getName();
		defaultListableBeanFactory.registerBeanDefinition(className, beanDefinitionBuilder.getBeanDefinition());
		return (T) applicationContext.getBean(className);
	}

	public static void destroy(String className){
		defaultListableBeanFactory.removeBeanDefinition(className);
		System.out.println("destroy " + className);
	}
}

二、使用工具类注入类

UserService userService= SpringCtxUtil.getBean(UserService.class);

三、注意

 在我们需要调用的类前加上注解@Primary

@Primary
public Class UserService {

}

如果我们在需要注入的类中使用了@Transactional注解，一般会导致注入失败，请参考下面的博文

 https://blog.csdn.net/weixin_36524613/article/details/85258442