Spring中的Aware-优快云博客

Aware接口

Spring中提供了一些以Aware结尾的接口，实现Aware接口的Bean在被初始化之后，可以获取相应资源
通过Aware接口，可以对Spring相应资源进行操作
为对Spring进行简单的扩展提供了方便的入口

例如ApplicationContextAware接口，BeanNameAware接口。

以下对ApplicationContextAware接口，BeanNameAware接口进行简要的分析；

ApplicationContextAware接口用于在Bean中获取ApplicationContext实例。

BeanNameAware接口用于在Bean中获取当前Bean注册到IoC容器中的id名称。

测试前准备工作

说明ABCApplicationContext.java 实现ApplicationContextAware接口的类

ABCBeanName.java 实现BeanNameAware接口的类

AwareTest.java 单元测试类

Spring-aware.xml SpringBean配置文件

ABCBeanName.java

package com.abc;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public class ABCApplicationContext implements ApplicationContextAware {

	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		// TODO Auto-generated method stub
		ABCApplicationContext context = (ABCApplicationContext)applicationContext.getBean("applicationContextAware");
		System.out.println("ABCApplicationContext " + context.getClass().getName());
	}

}

ABCBeanName.java

package com.abc;

import org.springframework.beans.factory.BeanNameAware;

public class ABCBeanName implements BeanNameAware {

	@Override
	public void setBeanName(String name) {
		// TODO Auto-generated method stub
		System.out.println("ABCBeanName " + name);
	}

}

AwareTest.java

package com.abc;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;
import org.springframework.context.support.ClassPathXmlApplicationContext;

@RunWith(BlockJUnit4ClassRunner.class)
public class AwareTest {
	private ClassPathXmlApplicationContext context = null;
	@Before
	public void init(){
		context = new ClassPathXmlApplicationContext("classpath:Spring-aware.xml");
	}
	@After
	public void destroy(){
		context.destroy();
	}
	@Test
	public void test(){
		
	}
	
}

Spring-aware.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
	<bean id="applicationContextAware" class="com.abc.ABCApplicationContext"></bean>
	<bean id="beanNameAware" class="com.abc.ABCBeanName"></bean>
</beans>

测试结果

四月 25, 2017 8:22:24 上午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@182decdb: startup date [Tue Apr 25 08:22:24 HKT 2017]; root of context hierarchy
四月 25, 2017 8:22:24 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [Spring-aware.xml]
ABCApplicationContext com.pioneer.other.ABCApplicationContext
ABCBeanName beanNameAware
四月 25, 2017 8:22:25 上午 org.springframework.context.support.ClassPathXmlApplicationContext doClose
信息: Closing org.springframework.context.support.ClassPathXmlApplicationContext@182decdb: startup date [Tue Apr 25 08:22:24 HKT 2017]; root of context hierarchy

结论：ApplicationContextAware接口，BeanNameAware接口可以认为是获取相应Spring容器资源的回调方法，可以方便的获取到相应的资源。一个Bean同时实现ApplicationContextAware接口，BeanNameAware接口，IoC容器的调用顺序是BeanNameAware接口的实现，然后是ApplicationContextAware接口的实现。

转载于:https://my.oschina.net/pioneerDev/blog/886471