Spring boot: Start an application automatically when Webshere Application Server starts? - spring

Question

Assume I have a SpringBoot Application deployed as a WAR to Websphere Application Server (WAS). This WAR contains a daemon, so it must start straight away when WAS starts (and only once).
However, I still need to activate the SpringBoot Servlet by doing a http request.
Now I understand that the concept of servlets is to act on http requests, I still want to get it auto started on appserver start. This makes my daemon portable from standalone jar/main to war/webapp.
I tried a ServletContextListener, but the contextInitalized also get only called at the first http request.
I do not have a web.xml (servlet 3).
Code:
#SpringBootApplication
#WebListener
public class DemoApplication extends SpringBootServletInitializer implements ServletContextListener {
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
System.err.println("ONSTARTUP");
super.onStartup(servletContext);
}
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
#Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(DemoApplication.class);
}
#Override
public void contextInitialized(ServletContextEvent sce) {
System.err.println("contextInitialized");
}
#Override
public void contextDestroyed(ServletContextEvent arg0) {
//
}
}
and:
#Component
public class DemoRunner implements ApplicationRunner {
#Override
public void run(ApplicationArguments arg0) throws Exception {
System.err.println("I AM RUNNING");
}
}
When I start WAS I first get this:
Launching defaultServer (WebSphere Application Server
16.0.0.2/wlp-1.0.13.cl160220160526-2258) on Java HotSpot(TM) 64-Bit Server VM, version 1.7.0_79-b15 (en_US)
[...]
[AUDIT ] CWWKT0016I: Web application available (default_host): http://localhost:9080/demo/
[AUDIT ] CWWKZ0001I: Application test started in 17,282 seconds.
To get my Spring Boot application starting, I first need to visit this link (http:/localhost:9080/demo/). Then it starts rolling, starting with the startup method as you can see in the log. But how can I get this starting without doing a http request?
[err] ONSTARTUP
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.4.0.RELEASE)
2016-09-02 10:45:52.670 INFO 23716 --- [dPool-thread-48] com.example.DemoApplication : Starting DemoApplication on [...]
2016-09-02 10:45:58.019 INFO 23716 --- [dPool-thread-48] o.s.c.support.DefaultLifecycleProcessor : Starting beans in phase 0
[...]
[err] I AM RUNNING
[...]
2016-09-02 10:45:58.093 INFO 23716 --- [dPool-thread-48] com.example.DemoApplication : Started DemoApplication in 6.372 seconds (JVM running for 31.549)
[...]
[err] contextInitialized
[err] contextInitialized

Answer 1

You can change the loadOnStartup by customize the spring dispatch servlet, here is the sample question and you can use the code
#Bean
public static BeanFactoryPostProcessor beanFactoryPostProcessor() {
return new BeanFactoryPostProcessor() {
#Override
public void postProcessBeanFactory(
ConfigurableListableBeanFactory beanFactory) throws BeansException {
BeanDefinition bean = beanFactory.getBeanDefinition(
DispatcherServletAutoConfiguration.DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME);
bean.getPropertyValues().add("loadOnStartup", 1);
}
};
}
Reference:
how to configure 'dispatcherServlet' load on startup by spring boot?
Upate
Seems there is a more simple way, you can config it in application.properites
spring.mvc.servlet.load-on-startup=1