Spring的依赖查找方式

根据Bean名称查找

Spring方式

public static void main(String[] main) {
    BeanFactory beanFactory = new ClassPathXmlApplicationContext("classpath:/META-INF/bean.xml");
    User user = beanFactory.getBean("user");
}

Spring Boot方式

@Component
public class SpringContextUtil implements ApplicationContextAware {
    private static ApplicationContext applicationContext;
    public SpringContextUtil() {
    }
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        applicationContext = applicationContext;
    }
    public static <T> T getBean(String name) {
        return this.applicationContext.getBean(name);
    }
}

根据Bean类型查找

Spring方式

# 根据类型查找只有一个bean
public static void main(String[] main) {
    BeanFactory beanFactory = new ClassPathXmlApplicationContext("classpath:/META-INF/bean.xml");
    User user = beanFactory.getBean(User.class);
}
# 根据类型查找存在多个bean
public static void main(String[] main) {
    BeanFactory beanFactory = new ClassPathXmlApplicationContext("classpath:/META-INF/bean.xml");
    if(beanFactory intanceof ListableBeanFactory) {
        ListableBeanFactory listableBeanFactory = (ListableBeanFactory) beanFactory;
        Map<String, User> users = listableBeanFactory.getBeansOfType(User.class);
    }
}

Spring Boot方式

@Component
public class SpringContextUtil implements ApplicationContextAware {
    private static ApplicationContext applicationContext;
    public SpringContextUtil() {
    }
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        applicationContext = applicationContext;
    }
    public static <T> T getBean(Class<T> clazz) {
        return this.applicationContext.getBeansOfType(clazz);
    }
}