Go语言视频零基础入门到精通

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一初始化与销毁

1.通过设置bean的init-mothed属性指定初始化的方法,他的限制是方法无法接受任何参数,方法可以为static

2.实现InitializingBean接口的afterPropertiesSet()方法

3.最好的方法是在afterProptertiesSet()中调用自定义初始化方法

4.销毁单例对象可以通过指定bean的destroy-method属性,指定销毁时执行的方法名

5.销毁单例对象可以通过实现DisposableBean的destroy实现

6.销毁方法的触发是通过生成该单例对象的BeanFactory的destroySingletons方法的执行而触发

7.通过指定 ShutdownHook可以指定一个线程来执行BeanFactory的destroySingletons方法

8.如果同时指定两种初始化和销毁方法,初始化接口方法首先运行,参数话初始化方法后运行;销毁时,接口中的销毁方法首先运行,参数指定的销毁方法后运行

二代码

1bean

package study.spring;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.DisposableBean;

public class ContextTest implements InitializingBean,DisposableBean {

    private String content;
   
    public void init(){ System.out.println("mothed init run."); }
   
    public void afterPropertiesSet() throws java.lang.Exception{
        if (content== null) content="hello";
        System.out.println("afterPropertiesSet run.");
    }
   
    public String getContent(){ return content; }
   
    public void setContent(String content){ this.content = content; }
   
    public void dispose(){ System.out.println("mothed despose run."); }
   
    public void destroy(){
        content = null;
        System.out.println("destroy run.");
    }
   
}

2测试程序

package study.spring;

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

public class SimpleInject{
   
   
   
   public static void main(String[] args){
    ConfigurableListableBeanFactory beanFactory3 = new XmlBeanFactory(new FileSystemResource("./spring_xml/beans_teacher.xml"));
    ConfigurableListableBeanFactory beanFactory1 = new XmlBeanFactory(new FileSystemResource("./spring_xml/beans.xml"),beanFactory3);
    ConfigurableListableBeanFactory beanFactory2 = new XmlBeanFactory(new FileSystemResource("./spring_xml/beans_address.xml"));      
    Runtime.getRuntime().addShutdownHook( new Thread(new ShutdownHook(beanFactory2)));
    Student student1 = (Student)beanFactory1.getBean("student");
    ContextTest ct = (ContextTest)beanFactory2.getBean("context");
    System.out.println(ct.getContent());
   }

}

class ShutdownHook implements java.lang.Runnable{
      
       private ConfigurableListableBeanFactory cbf;
      
       public ShutdownHook(ConfigurableListableBeanFactory cbf){ this.cbf = cbf; }
      
       public void run(){
          cbf.destroySingletons();
       }
      
   }