Why in destroy method is not called automatically in below when object will destroy?

Question

public class Instrumentalist implements Performer, InitializingBean, DisposableBean {
 private Instrument instrument;
 private String song;
 public void setInstrument(Instrument instrument)
 {
     this.instrument=instrument;
 }

 public void setSong(String song)
 {
     this.song=song;
 }

 public void afterPropertiesSet() throws Exception
 {
     System.out.println("Before Playing Instrument");
 }

 public void destroy() throws Exception
 {
     System.out.println("After Playing Instrument");
 }

  public void perform() {
    // TODO Auto-generated method stub
    System.out.println("Playing "+ song + " : ");
    instrument.play();
   }

}

In above example only i got the out put in which afterPropertiesSet() is called but not destroy method. Below is my config.xml

<bean id="dhiraj" class="Instrumentalist">
    <property name="song" value="Sa Re Ga Ma" />
    <property name="instrument" ref="piano" />
</bean>

<bean id="piano" class="Piano" />

and i called from my main method as below -

ApplicationContext context = new ClassPathXmlApplicationContext("Spring-config.xml");
Performer performer1=(Performer)context.getBean("dhiraj");
performer1.perform();

Answer 1

Try this:

AbstractApplicationContext context = new ClassPathXmlApplicationContext("Spring-config.xml");
//...
context.close();    //!!!

You have to close the context manually, otherwise Spring does not know that the bean is no longer needed and should be destroyed. Note that you have to use AbstractApplicationContext type as ApplicationContext interface does not define close().

Answer 2

For singleton beans like dhiraj, the destroy() lifecycle method will be called when, and only when, the application context is shut down.

If your code fragment is the entirety of your program, then destroy() will not be called because you're not closing the context properly.

Add context.close() to the end of your fragment, and you'll see destroy() being called.