Comment by bdangubic
3 days ago
this is exactly why spring succeeded. I need to run a scheduled job, @EnableScheduling then @Scheduled(cron = “xxxxxx”) - done. I need XYZ, @EnableXYZ the @XYZ… sh*t just works…
3 days ago
this is exactly why spring succeeded. I need to run a scheduled job, @EnableScheduling then @Scheduled(cron = “xxxxxx”) - done. I need XYZ, @EnableXYZ the @XYZ… sh*t just works…
And then I realize I need to change that schedule. And would like to do it without recompiling my code. Oh, and I need to allow for environment specific scheduling, weekdays on one system, weekends on others. And I need other dependencies that are environment specific.
I much prefer Spring's XML configuration from the old days. Yeah, XML sucks and all that. But still, with XML, the configuration is completely external from the application and I can manage it from /etc style layouts. Hard coding and compiling in dependency injection via annotations or other such behaviors into the class directly has caused me grief over the long term pretty much every time.
I do realize you were intending to give examples of why you don't think annotations aren't very extensible, but it is an odd example as all those things can still be achieved via annotation, since the annotations can accept values loaded from env specific properties.
Exactly this, it’s great fun to have a surface level understanding of a topic and post derisively for internet points; rather then spend the time and effort to actually learn about the subject at hand!
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> env specific properties
And then if you want to change a value at runtime you have to restart the executable?
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The only real-world usage I see for annotations are in GSON (the @Expose) and JUnit with @Test.
Never really came across with any other real cases where it solves a pressing issue as you mention. Most times is far more convenient to do things outside the compiled code.
Agreed. These are good examples where annotations seem like a good fit. Being able to tell a processor that a method or field is "special". Test methods, serializable hints, etc.
It's kind of like, when annotations were delivered to Java, lots of projects thought they were just the next greatest thing. I followed right along at the time, as well.
But over time, finding the value in the configuration-as-code approach to application deployment, I definitely feel that annotations have been abused for many use cases.
all trivial things you are listing, every single one…
So…pass that variable to your annotation.
I’m not seeing the point?
You do know about environmental variables?
Yeah, it works until it isn't. And they good luck debugging it. I'd prefer simple obvious linear code calling some functions over this declarative magic any day.
This isn't any harder than annotation. But you can ctrl+click on schedule implementation and below easily. You can put breakpoint and whatnot.
never had any issues debugging as I am never debugging the scheduler (that works :) ) but my own code.
and what exactly is “cronService”? you write in each service or copy/paste each time you need it?
`cronService` is an injected instance of some class, probably provided by framework. My point is to demonstrate alternative, imperative way of defining cron tasks, as compared to declarative one.
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You can write your own libraries?
My goodness. What a question!
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Then you need to deploy it on multiple nodes and neex to make sure it only runs once for each run of the cron, etc.
I believe Quartz is the go-to solution for this. It's not part of Spring but it offers a similar annotation-driven interface, but with distributed locking via a database
Absolutely! But Quartz is also quite heavy. If all you need is to ensure scheduled jobs run in a clustered environment there are more “lighweight” options
Like Shedlock?
while not working on out of the box clustered this is trivial issue to address