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Spring中提供了一些Aware接口，这些可以让bean被初始化（加载xml）之后获得一些资源，这里我们着重讲2个接口：ApplicationContextAware与BeanNameAware
第一步：配置xml，并实现要继承的2个类和测试类
xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<bean id="moocApplicationContext" class="com.imooc.aware.MoocApplicationContext"></bean>
<bean id="moocBeanName" class="com.imooc.aware.MoocBeanName"></bean>
</beans>
继承ApplicationContextAware的类
package com.imooc.aware;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
public class MoocApplicationContext implements ApplicationContextAware {
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
System.out.println(applicationContext.getBean("moocApplicationContext").hashCode());
}
}
继承BeanNameAware的类
package com.imooc.aware;
import org.springframework.beans.factory.BeanNameAware;
public class MoocBeanName implements BeanNameAware {
@Override
public void setBeanName(String Name) {
System.out.println("MoocBeanName"+Name);
}
}
测试类
package com.imooc.aware;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestAware {
public static void main(String[] args) {
ApplicationContext ctx=new ClassPathXmlApplicationContext("spring-aware.xml");
}
}
原理：在加载xml时，继承过ApplicationContextAware的类在重载方法setApplicationContext可以获取某一个bean的实例，即在加载xml过程，就可定义对象的实例
同样的对于继承过BeanNameAware的类而言，通过重写setBeanName可以获得该类的bean的id。
说到这里，其实我们通常会让一个类同时继承它们两个，然后获得这个类bean的id，在通过getbean（id）获得该类的实例，这样我们就在xml初始化时就定义好了一个实例
我们改写MoocBeanName来进行测试
package com.imooc.aware;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
public class MoocBeanName implements BeanNameAware,ApplicationContextAware {
String lblname=null;
@Override
public void setBeanName(String Name) {
lblname=Name;
System.out.println("MoocBeanName"+Name);
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
System.out.println(applicationContext.getBean(lblname).hashCode());
}
}
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