Better cold classes management

[a-peyrard]

This PR permits to manage several new things about cold classes.

• It permits to add inherited classes of cold components (components being loaded in the main factory, such as AutoStartable ones) in cold classes list.
• It adds a way to declare cold classes using a property: restx.cold.classes. The property value is a list of fqcn separated by :.
• It adds a way to declare cold classes using a resource file: META-INF/cold-classes.list. Resources will be loaded from the classloader, and every classes listed will be added to the cold classes list. The file must contains a list of fqcn, one per line.
• It provides a way to fulfil the resource file using an annotation: @Cold. So every classes annotated with @Cold will be added to the resource file (thanks to a new annotation processor).

[xhanin]

Sounds good to me. One question: is there any reason you use : as separator? I usually prefer using a comma to list values (when it's not conflicting with the values), I think it's more readable, especially if you trim the values you can have a very readable list.

[a-peyrard]

No reason, I just use to much ux systems :)

So I will change to , soon.

[a-peyrard]

Separator changed, if it's okay for you I will merge this tomorrow.

[xhanin]

Fine for me

[fcamblor]

Wow this seems really weird case ! :-)

Since the ex.getMessage() seems a very weird/tricky thing, I would use an intermediate variable (with explicit naming) to describe the fact that the filename is carried by the exception message (people don't always read javadoc, it will enforce this thing in code :-))

Last note : why not Throwables.propagate(exceptions) in catch clauses ?

[fcamblor]

👍 with some delay (sorry)

[a-peyrard]

I changed the trim, according to Xavier's remark (thanks to "push -f" :)).

[fcamblor]

@a-peyrard Just 1 simple question about @Cold annotation : will it work on only @Component-annotated classes or will it work under all circumstances ?

I'm facing some weird classloader issue and tried to fix it with @Cold annotation but it didn't worked (my classloader issue concerns a "standard" class, not a @Component)

[a-peyrard]

I just checked the code, and it should work for any classes, not only
@component. If you set the log level to "debug" for
RestxMainRouterFactory it should log the cold classes like this: "cold
classes: ..."

If it's not working you can try to add the property "restx.cold.classes" to
your JVM options, the value is a list of FQCN separated by commas.

On Fri, Oct 23, 2015 at 5:07 PM Frédéric Camblor notifications@github.com
wrote:

@a-peyrard https://github.com/a-peyrard Just 1 simple question about
@Cold annotation : will it work on only @Component-annotated classes or
will it work under all circumstances ?

I'm facing some weird classloader issue and tried to fix it with @Cold
annotation but it didn't worked (my classloader issue concerns a "standard"
class, not a @component)

—
Reply to this email directly or view it on GitHub
#175 (comment).

[fcamblor]

Yep, tried with the restx.cold.classes property as well and it didn't worked for my particular case

But no worries, my problem may not be related to hot reload (I only tried to fix it with cold classes but it didn't helped)

[xhanin]

Fred, I think it would be interesting to diagnose your issue more closely to see if it's not a problem with the new cold classes approach. I will try to check that with you next week or more probably the week after, since I won't be at the office next week.

[fcamblor]

I just created this repo reproducing my case (needs current restx version to compile well as it requires @Cold annotation)

if you run AppServer from it in dev mode, and go to http://127.0.0.1:8080/api/servletRootRealPath, you will see you have a null path returned whereas the ContainerListener has been initialized (and the App enum singleton initialized as well)

If you retry it in prod mode, everything will go well.

[a-peyrard]

I just cloned your repo, and I will try to explain what I understood.

The App.class is loaded a first time by the main classloader (being AppClassLoader), and after that the RestxMainRouterFactory initialize and create a first HotCompile classloader. Unfortunately this is this first HotCompile classloader which is used to load cold classes.
Then the request is made, and another HotReload classloader is created for the request. It finds the cold class (App), but the one loaded in the first HotReload classloader.

I manage to make it work by commenting the line:

mainFactoryClassLoader = hotReloadingClassLoader;

I don't know why I used this classloader to load the cold classes, I don't know what would be the impact, to use the original classloader instead of the one creating the main restx factory.

HTH