《Pro Spring》学习笔记之BeanNameAware和BeanFactoryAware

首先看代码实例：

SimpleBean.java

 

package ch5.BeanAware;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

import ch5.destroy.ShutDownHook;

public class SimpleBean implements InitializingBean,DisposableBean,BeanNameAware,BeanFactoryAware,Runnable ...{
  private ConfigurableListableBeanFactory configurableListableBeanFactory;
  public void setBeanName(String beanName) ...{
        System.out.println("this is info from BeanNameAware and beanName is:"+beanName);
        
    }
    public void setBeanFactory(BeanFactory factory) throws BeansException ...{
        //自动注册成线程
        if(factory instanceof ConfigurableListableBeanFactory)...{
            System.out.println("this is info from BeanNameAware and beanName");
            this.configurableListableBeanFactory=(ConfigurableListableBeanFactory)factory;
              Runtime.getRuntime().addShutdownHook(new Thread(this));
        }
        
    }
    public void afterPropertiesSet() throws Exception ...{
        System.out.println("this is info from afterpropertiesSet from SimpleBean");
    }
    public void run() ...{
        //线程调用destroySingletons
        configurableListableBeanFactory.destroySingletons();
        
    }
  private String name;
  private String sex;
  private String age;
  public void destroyMethod()...{
      System.out.println("this is info from customer destroy method");
  }
  public void destroy()...{
      System.out.println("this is info from destroy method");
  }
public String getAge() ...{
    return age;
}
public void setAge(String age) ...{
    this.age = age;
}
public String getName() ...{
    return name;
}
public void setName(String name) ...{
    this.name = name;
}
public String getSex() ...{
    return sex;
}
public void setSex(String sex) ...{
    this.sex = sex;
}
}

 配置文件：

 

<?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-2.0.xsd">

<bean id="SimpleBean" class="ch5.destroy.SimpleBean" destroy-method="destroyMethod">
<property name="name">
    <value>gaoxiang</value>
  </property>
<property name="sex">
   <value>male</value>
</property>
<property name="age">
    <value>26</value>
  </property>
</bean>


</beans>

 

测试代码：

 

package ch5.BeanAware;

import java.io.File;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;

public class TestSpring...{
  public static void main(String args[])  throws Exception...{
      //获取bean factory
      ConfigurableListableBeanFactory factory=(ConfigurableListableBeanFactory)getBeanFactory();  //使用子beanFactory
     
      factory.preInstantiateSingletons();
      SimpleBean bean1=(SimpleBean)factory.getBean("SimpleBean");
      


  }
  public static BeanFactory getBeanFactory()...{
      //获取bean factory
      String realpath="";
   
         //加载配置项
      realpath=System.getProperty("user.dir")+File.separator+"src"+File.separator+"ch5/destroy"+File.separator+"applicationContext.xml";
  
     
      ConfigurableListableBeanFactory  factory=new XmlBeanFactory(new FileSystemResource(realpath));
      
      return factory;
  }
}

 

一点说明：

实现BeanNameAware接口需要实现setBeanName()方法，这个方法只是简单的返回我们当前的beanName

实现BeanFactoryAware,我们

 public void run() ...{
    //线程调用destroySingletons
    configurableListableBeanFactory.destroySingletons();
        
}

可以调用到获得Bean的工厂，需要实现setBeanFactory方法

 

看测试程序的这段代码：

 

 ConfigurableListableBeanFactory factory=(ConfigurableListableBeanFactory)getBeanFactory();    
factory.preInstantiateSingletons();
SimpleBean bean1=(SimpleBean)factory.getBean("SimpleBean");

我们对ConfigurableListableBeanFactory .preInstantiateSingletons();进行了调用，默认情况下，只有用到singleton Bean的时候，spring才会使用懒汉式子进行初始化，这对SimpleBean可是个大麻烦，因为它需要实例化后才能注册成为shutdown hook,调用preInstantiateSingletons()可让spring立即处理其全部的bean定义并创建实例，测试代码中并没有调用destroySingleton(),因为simpleBean已经在run方法中进行调用了。如下：

 public void run() {
     //线程调用destroySingletons
  configurableListableBeanFactory.destroySingletons();
 }

运行结果：

this is info from BeanNameAware and beanName is:SimpleBean
this is info from BeanNameAware and beanName
this is info from afterpropertiesSet from SimpleBean
this is info from destroy method
this is info from customer destroy method

也可以看到，执行顺序是BeanNameAware,BeanFactoryAware,afterPropertiesSet,customer-Init,disposeable,customer-destroy