Spring boot Create a Deployable War File

It is easy to follow https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#howto-create-a-deployable-war-file

But here I want to add one thing is how to access the application context?

One way is you can get the context from below method return:

ConfigurableApplicationContext applicationContext = app.run(args);

Another is if you deploy the .war to external Tomcat server, the applicationContext may be null, in this case, you can get it from onStartup() method

@Overridepublic void onStartup(ServletContext servletContext) throws ServletException {
    WebApplicationContext rootAppContext = createRootApplicationContext(servletContext);
    if (rootAppContext != null) {

        // set context into your own class, say MySpringContext here
        MySpringContext.setContext(rootAppContext);
        servletContext.addListener(new ContextLoaderListener(rootAppContext) {
            @Override            public void contextInitialized(ServletContextEvent event) {
                // no-op because the application context is already initialized            }
        });
    }
    else {
        this.logger.debug("No ContextLoaderListener registered, as " + "createRootApplicationContext() did not "                + "return an application context");
    }
}