Make AbstractTemplateEngine#init method final, use lazy instantiation

[decebals]

The goal of this PR is to facilitate #590.
I think that now the code looks better and the performance is a little better (using lazy instantiation).

[mhagnumdw]

@decebals , I took a look over and it looks ok. Tomorrow I will test it with my application that uses Freemarker. Then I come back here.

[mhagnumdw]

@decebals , please see this comment: d0793e2#r61118560-permalink

[decebals]

@decebals , please see this comment: d0793e2#r61118560-permalink

See https://github.com/pippo-java/pippo/blob/master/pippo-controller-parent/pippo-weld/src/test/java/ro/pippo/weld/ControllerInterceptorTest.java#L95

My idea is to bring each component where is used. Now many components extract dependencies from Application and ControllerApplication. Probably in the future we can remove Application and ControllerApplication entirely. It's hard to test some come components because they receive application instance as parameter and you (developer) don't know what this component uses from application.

I recognize that now is a little bit verbose to set a custom ControllerFactory. Maybe to add ControllerHandlerFactory is too much, and we should put the logic of this component in ControllerRouteFactory and to remove it (ControllerHandlerFactory).
The good news is that in the future we don't need pippo-spring, pippo-guice anymore, no need to set a custom ControllerFactory to achieve integration with DI containers.

Please feel free to say what you think, because your feedback is important to me.

[decebals]

Remove ControllerHandlerFactory layer to simplify injection of custom ControllerFactory in DefaultControllerRouteFactory.

[mhagnumdw]

See https://github.com/pippo-java/pippo/blob/master/pippo-controller-parent/pippo-weld/src/test/java/ro/pippo/weld/ControllerInterceptorTest.java#L95

I did as in the test class above and in my application I got the error stack below:

Error: declares @Produces("application/json") but there is no registered ContentTypeEngine for that type!

Exception in thread "main" ro.pippo.core.PippoRuntimeException: javax.servlet.ServletException: ro.pippo.core.PippoRuntimeException: br.com.myapp.controller.cofre.CofreConsultaNgController::commandSearch declares @Produces("application/json") but there is no registered ContentTypeEngine for that type!
	at ro.pippo.jetty.JettyServer.start(JettyServer.java:84)
	at ro.pippo.core.Pippo.start(Pippo.java:158)
	at br.com.myapp.PippoLauncher.main(PippoLauncher.java:68)
Caused by: javax.servlet.ServletException: ro.pippo.core.PippoRuntimeException: br.com.myapp.controller.cofre.CofreConsultaNgController::commandSearch declares @Produces("application/json") but there is no registered ContentTypeEngine for that type!
	at ro.pippo.core.PippoFilter.init(PippoFilter.java:115)
	at ro.pippo.jetty.websocket.JettyWebSocketFilter.init(JettyWebSocketFilter.java:43)
	at org.eclipse.jetty.servlet.FilterHolder.initialize(FilterHolder.java:140)
	at org.eclipse.jetty.servlet.ServletHandler.lambda$initialize$0(ServletHandler.java:731)
	at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
	at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:742)
	at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
	at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:755)
	at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:379)
	at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:911)
	at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:288)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:169)
	at org.eclipse.jetty.server.Server.start(Server.java:423)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:110)
	at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:97)
	at org.eclipse.jetty.server.Server.doStart(Server.java:387)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73)
	at ro.pippo.jetty.JettyServer.start(JettyServer.java:81)
	... 2 more
Caused by: ro.pippo.core.PippoRuntimeException: br.com.myapp.controller.cofre.CofreConsultaNgController::commandSearch declares @Produces("application/json") but there is no registered ContentTypeEngine for that type!
	at ro.pippo.controller.ControllerHandler.validateProduces(ControllerHandler.java:313)
	at ro.pippo.controller.ControllerHandler.<init>(ControllerHandler.java:86)
	at ro.pippo.controller.DefaultControllerHandlerFactory.createRouteHandler(DefaultControllerHandlerFactory.java:37)
	at ro.pippo.controller.DefaultControllerRouteFactory.createRoute(DefaultControllerRouteFactory.java:41)
	at ro.pippo.controller.ControllerRegistry.createControllerRoutes(ControllerRegistry.java:231)
	at ro.pippo.controller.ControllerRegistry.registerControllerMethods(ControllerRegistry.java:169)
	at ro.pippo.controller.ControllerRegistry.register(ControllerRegistry.java:129)
	at ro.pippo.controller.ControllerRegistry.register(ControllerRegistry.java:95)
	at ro.pippo.controller.ControllerApplication.addControllers(ControllerApplication.java:104)
	at br.com.myapp.handlers.init.LoadApi.handle(LoadApi.java:130)
	at br.com.myapp.handlers.init.LevelHandler.handle(LevelHandler.java:46)
	at br.com.myapp.PippoApplication.onInit(PippoApplication.java:82)
	at ro.pippo.core.Application.init(Application.java:114)
	at ro.pippo.core.route.RouteDispatcher.init(RouteDispatcher.java:71)
	at ro.pippo.core.PippoFilter.init(PippoFilter.java:108)
	... 20 more

So I needed to set the ContentTypeEngines in DefaultControllerHandlerFactory. That's right? Thus:

public class PippoApplication extends ControllerApplication {
    @Override
    protected void onInit() {
        ControllerFactory controllerFactory = new GuiceControllerFactory(injector);
        ControllerHandlerFactory controllerHandlerFactory = new DefaultControllerHandlerFactory()
            .setControllerFactory(controllerFactory)
            .setContentTypeEngines(getContentTypeEngines()) // <<< I had to define here
            ;
        ControllerRouteFactory controllerRouteFactory = new DefaultControllerRouteFactory()
            .setControllerHandlerFactory(controllerHandlerFactory)
            ;
        setControllerRouteFactory(controllerRouteFactory);
    }
}

If I don't set the engines in the DefaultControllerHandlerFactory, it will instantiate an empty ContentTypeEngines in the getContentTypeEngines() method.

[mhagnumdw]

Remove ControllerHandlerFactory layer to simplify injection of custom ControllerFactory in DefaultControllerRouteFactory.

oops, I'll check this change...

[mhagnumdw]

@decebals , the observation I made above #591 (comment) is still valid.

It was necessary to set: .setContentTypeEngines(getContentTypeEngines()). That's right?

ControllerFactory controllerFactory = new GuiceControllerFactory(injector);
ControllerRouteFactory controllerRouteFactory = new DefaultControllerRouteFactory()
    .setControllerFactory(controllerFactory)
    .setContentTypeEngines(getContentTypeEngines()) // <<< I had to define here - getting from Application
    ;
setControllerRouteFactory(controllerRouteFactory);

[decebals]

It was necessary to set: .setContentTypeEngines(getContentTypeEngines()). That's right?

Yes. We will see in the future if we can improve this.

[decebals]

From what I see, we don't need ro.pippo.core.ContentTypeEngine#init(Application). Nothing happens there (less in the Gson based implementation but I think that we can move the creation of Gson in a lazy getter method).
I will come with a new PR with this improvement related to ContentTypeEngine but for the moment I want to be sure that we don't damage something in what exists already. So, check and close each PR, one by one, to isolate possible regressions.

By the way, the new release will be 2.0.0 because we will modify/improve substantial some things (break of API).

[mhagnumdw]

Well... these changes worked in my application with the modifications I mentioned earlier. I will then approve this PR.

[decebals]

Well... these changes worked in my application with the modifications I mentioned earlier. I will then approve this PR.

I don't understand. Is it works and I can merge it or do you need more time for a test?