Support org.springframework.context.ApplicationContextInitializer usage programmatically (in Servlet 3.0+ environments) [SPR-12430]

[spring-projects-issues]

Hendy Irawan opened SPR-12430 and commented

org.springframework.context.ApplicationContextInitializer is only usable from context-param or init-param.

It should also be usable programmatically, e.g. from WebApplicationInitializer implementation:

@Override
protected WebApplicationContext createRootApplicationContext() {
	final ConfigurableWebApplicationContext webAppCtx = (ConfigurableWebApplicationContext) super.createRootApplicationContext();
	// this throws NullPointerException due to ServletContext not yet assigned to webAppCtx
	new AppInitializer().initialize(webAppCtx);
	// Ideally
	webAppCtx.setInitializers(webAppCtx);
	return webAppCtx;
}

Workaround:

@Override
public void onStartup(ServletContext servletContext)
		throws ServletException {
	// Workaround
	servletContext.setInitParameter("contextInitializerClasses", AppInitializer.class.getName());
	super.onStartup(servletContext);
	servletContext.addListener(RequestContextListener.class);
}

---

Affects: 4.1.2

Issue Links:

• Provide a mechanism for adding ApplicationContextInitializer instances [SPR-11615] #16238 Provide a mechanism for adding ApplicationContextInitializer instances ("is duplicated by")

[spring-projects-issues]

Juergen Hoeller commented

We got a setContextInitializers method on FrameworkServlet, so this can be programmatically configured there already. As a consequence, I wouldn't put a setInitializers method onto ConfigurableWebApplicationContext itself but rather onto ContextLoader, analogous to the arrangement in FrameworkServlet, processed at the very same time as "contextInitializerClasses".

Juergen

[spring-projects-issues]

Juergen Hoeller commented

Following up on the above, I've added a setContextInitializers method to ContextLoader, also exposed on the ContextLoaderListener subclass. I'm also considering first-class support in AbstractContextLoaderInitializer since the ContextLoaderListener isn't currently exposed there. Taking AbstractDispatcherServletInitializer into account as well, it'd be nice to provide support for 'global' initializers as well as context-local initializers, analogous to the current context-param variants.

Juergen

[spring-projects-issues]

Juergen Hoeller commented

This is ready now and will be available in the next 4.2 snapshot.

AbstractContextLoaderInitializer has a protected getRootApplicationContextInitializers method now, and AbstractDispatcherServletInitializer a corresponding getServletApplicationContextInitializers method. Since it's easy enough to expose the same initializer to both contexts, I've left it at that, not adding an extra method for global initializers. Re-applying global initializers is also a bit harder here since it's about initializer instances (which are supposed to be independent per context) instead of the initializer classes approach at the context-param level.

Juergen

[spring-projects-issues]

cemo koc commented

Juergen, this issue seems a duplicate issue this one #16238. Please resolve my issue as well.

Cheers