Aware&原理---Spring源码从入门到精通(十四)

bug学弟 lv.1

发布时间：2022-11-04 08:03:51 253

一、Aware的使用

自定义组件想要使用spring底层组件，他们都是由xxxProcessor后置处理器处理的，比如AppicationContextAware，创建完bean之后，吧相关的组件传入自定义的bean。

下面介绍三个，实现ApplicationContextAware可以setIOC容器，BeanNameAware可以获取当前组件名字，EmbeddedValueResolver可以解析。

/**
 * red
 *
 * @author keying
 *
 * Aware能把spring底层组件传入自定义的bean中，
 * 比如beanNameAware和ApplicationContextAware都是由xxxProcess(如：ApplicationContextAwareProcessor)
 * ApplicationContextAwareProcessor后置处理器，创建完bean之后，就吧相关的组件传入自定义组件中
 */
@Component
public class Red implements ApplicationContextAware, BeanNameAware, EmbeddedValueResolverAware {

    private ApplicationContext applicationContext;
    private String computer;

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        System.out.println("spring底层传入自定义组件的容器：" + applicationContext);
        this.applicationContext = applicationContext;
    }

    public void setBeanName(String name) {
        System.out.println("实现beanNameAware获取当前bean的name:" + name);
    }

    public void setEmbeddedValueResolver(StringValueResolver resolver) {
        String string = resolver.resolveStringValue("此电脑是：${os.name},生产时间：#{2021-3}");
        this.computer = string;
        System.out.println("embeddedValueResolver:" + string);
    }
}

@Test
    public void test1() {
        //getBeanNames(applicationContext);

        //BookService bookService = applicationContext.getBean(BookService.class);
        //BookDao bookDao = applicationContext.getBean(BookDao.class);
        //System.out.println("bookService:" + bookService);
        //System.out.println("bookDao:" + bookDao);
        System.out.println("=============从容器中获取Boss中的car========");
        Boss boss = applicationContext.getBean(Boss.class);
        System.out.println("boss:" + boss);
        Car car = applicationContext.getBean(Car.class);
        System.out.println("car:" + car);
        System.out.println("=============从Color中获取car");
        Color color = applicationContext.getBean(Color.class);
        System.out.println("color:" + color);
        System.out.println("ioc容器里的：" + applicationContext);
        applicationContext.close();
    }