5.2.8. Application Lifecycle Events

There are the following types of lifecycle events in a CUBA application:

AppContextInitializedEvent

It is sent right after AppContext is initialized. At this moment:

  • All the beans are fully initialized and their @PostConstruct methods are executed.

  • Static AppBeans.get() methods can be used for obtaining beans.

  • The AppContext.isStarted() method returns false.

  • The AppContext.isReady() method returns false.

AppContextStartedEvent

It is sent after AppContextInitializedEvent and after running all AppContext.Listener.applicationStarted(). At this moment:

  • The AppContext.isStarted() method returns true.

  • The AppContext.isReady() method returns false.

  • On the middleware, if cuba.automaticDatabaseUpdate application property is enabled, all database update scripts are successfully executed.

AppContextStoppedEvent

It is sent before the application shutdown and after running all AppContext.Listener.applicationStopped(). At this moment:

  • All the beans are operational and can be obtained via AppBeans.get() methods.

  • AppContext.isStarted() method returns false.

  • The AppContext.isReady() method returns false.

You can affect the order of listeners invocation by specifying the @Order annotation. The Events.HIGHEST_PLATFORM_PRECEDENCE and Events.LOWEST_PLATFORM_PRECEDENCE constants define the range which is used by listeners defined in the platform.

For example:

package com.company.demo.core;

import com.haulmont.cuba.core.global.Events;
import com.haulmont.cuba.core.sys.events.*;
import org.slf4j.Logger;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;

import javax.inject.Inject;

@Component
public class MyAppLifecycleBean {

    @Inject
    private Logger log;

    // event type is defined by annotation parameter
    @EventListener(AppContextInitializedEvent.class)
    // run after all platform listeners
    @Order(Events.LOWEST_PLATFORM_PRECEDENCE + 100)
    private void appInitialized() {
        log.info("Initialized");
    }

    // event type is defined by method parameter
    @EventListener
    private void appStarted(AppContextStartedEvent event) {
        log.info("Started");
    }

    @EventListener
    private void appStopped(AppContextStoppedEvent event) {
        log.info("Stopped");
    }
}
ServletContextInitializedEvent

It is published right after initialization of Servlet and Application contexts. At this moment:

  • Static AppBeans.get() methods can be used for obtaining beans.

  • This event contains application and servlet contexts, thus enabling to register custom Servlets, Filters and Listeners, see Registration of Servlets and Filters.

ServletContextDestroyedEvent

It is published when Servlet and Application are about to be shut down and enables to free resources manually.

For example:

@Component
public class MyInitializerBean {

    @Inject
    private Logger log;

    @EventListener
    public void foo(ServletContextInitializedEvent e) {
        log.info("Application and servlet context is initialized");
    }

    @EventListener
    public void bar(ServletContextDestroyedEvent e) {
        log.info("Application is about to shut down, all contexts are now destroyed");
    }
}