Spring @PreDestroy and @PostConstruct annotations

Question

I am trying to start and stop a quartz scheduler in a spring singleton bean .But postconstruct is getting called two times and predestroy is not called at all . This link says that because of proxying it natural to be called twice but this is causing exception in the postconstruct method . I only want the postConstruct to be called once after the singleton bean is loaded.

Answer 1

why don't you try this using an init-method or try implementing the initializing bean . These provide alternative approaches to postConstruct .

When the spring beans are unloaded i.e , when the container is shut down or the close() method in ConfigurableApplicationContext method gets called through some other means, the preDestroy is invoked.

Answer 2

I write a contextloader listener and change web.xml listener .So I can initialize bean only one times.

 <listener>
        <listener-class>
              CustomContextLoaderListener
        </listener-class>
    </listener>

public class CustomContextLoaderListener  extends  
                        org.springframework.web.context.ContextLoaderListener{
     Scheduler scheduler;

    @Override
     public void contextInitialized(javax.servlet.ServletContextEvent event) {
             try{
             super.contextInitialized(event);
             this.scheduler= WebApplicationContextUtils.getWebApplicationContext(event.getServletContext()).getBean(Scheduler.class);

    }

    @Override
    public void contextDestroyed(ServletContextEvent event){

          super.contextDestroyed(event);
          scheduler.stopSchedulers();


    }