第2关：bean 的生命周期

题解代码：

1.applicationContext.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 ="dog" class="educoder.Dog"></bean>
	<bean id="student" class="step2.Student">
		<property name="name" value="Tom"></property>
	</bean>
	<!-- 配置后处理器  -->
	<bean class="step2.MyBeanPostProcessor"></bean>
</beans>

2.MyBeanPostProcessor.java

package step2;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;

/**********   Begin   **********/
public class MyBeanPostProcessor implements BeanPostProcessor{
    
    
    
	@Override
    public Object postProcessAfterInitialization(Object bean, String beanname) throws BeansException {
    
    
        Student stu= null; 
	    System.out.println("对初始化之后的Bean进行处理,将Bean的成员变量的值修改了");
		if("name".equals(beanname)||bean instanceof Student){
    
    
		stu=(Student) bean;
		stu.setName("Jack");
		} 
        return  stu;
    }
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanname) throws BeansException {
    
    
        System.out.println("初始化Bean之前的处理,此时我的名字:"+bean);
        return bean;
    }
}
/**********   End   **********/

3.Student.java

package step2;

import org.springframework.beans.factory.BeanNameAware;

/**********   Begin   **********/
public class Student implements BeanNameAware{
    
    
    private String name;
    public Student() {
    
    }

    public void setName(String name) {
    
    
		System.out.println("设置对象属性setName()");
        this.name = name;
    }

    //实现BeanNameAware接口  并重写setBeanName方法
	@Override
    public void setBeanName(String beanName){
    
    
		System.out.println("调用BeanNameAware的setBeanName()方法");
	}
    

    @Override
    public String toString() {
    
    
        return "Student{" +
                "name='" + name + '\'' +
                '}';
    }
}
/**********   End   **********/

4.Task.java

package step2;

import educoder.Dog;
import step2.MyBeanPostProcessor;
import step2.Student;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Task {
    
    
    public Student getBean(){
    
    
        /**********   Begin   **********/
		ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
		Student student = app.getBean("student",Student.class);
        return student;
        /**********   End   **********/
    }

}