CODEWITHSUNDEEP
javaspringspring-mvc
saarp
saarp

Reputation: 1951

Spring application initalization

I'm trying to initialize some beans during application start that will be reading from static shared in-memory structures. I was previously using @PostContruct but would like to shift to a more event-based initialization so that I can make use of Spring AOP features (Config, Resources, etc.) and avoid repeating myself.

All data beans implement this interface:

public interface DataInterface {
    public void loadData();

    public List<String> getResults(String input);
}

I have tried implementing both ServletContextListener and WebApplicationInitializer interfaces, but neither seem to get called.

@Service
public class AppInit implements WebApplicationInitializer {
    @Autowired
    DataInterface[] dataInterfaces;

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        // This does not get called
        for (DataInterface interface : dataInterfaces)
            interface.loadData();
    }
}


@WebListener
public class AppContextListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        // does not get called
    }

    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        // does not get called
    }
}

I could also try to initialize these classes at the end of the main() function that returns after I start the SpringApplication. 

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
        // Can I initialize the DataInterfaces here???
    }
}

Seems like there should be a better way.

Edit:

I ended up using the following solution since I wasn't able to receive any of the Context* events listed in the Spring docs.

@Component
public class DalInitializer implements ApplicationListener {
    @Autowired
    DataInterface[] dataInterfaces;

    @Override
    public void onApplicationEvent(ApplicationEvent applicationEvent) {
        if (applicationEvent.getClass() == ApplicationReadyEvent.class) {
            for (DataInterface interface : dataInterfaces)
                interface.loadData();
        }
    }
}

Upvotes: 0

Views: 44

Answers (1)

Stefan Isele - prefabware.com
Stefan Isele - prefabware.com

Reputation: 9516

Use spring application event listeners, see Better application events in Spring Framework

Upvotes: 1

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