scala- error loading a properties file packed inside jar - scala

Question

This is a newbie question, I read a lot but I am a bit confused.
I pass a properties file from inside a Jar, configuration is read, all is fine.
I wanted to add a try catch.I tried this but it does not work because the loading does not produce an exception if the properties file is not present. Therefore 3 questions:
Is it correct to load files like this?
Does it make sense to put a try/catch since the config is inside the jar?
If so, any suggestions on how to?
var appProps : Config = ConfigFactory.load()
try {
appProps = ConfigFactory.load("application.properties")
} catch {
case e: Exception => {
log.error("application.properties file not found")
sc.stop()
System.exit(1)
}
}

Answer 1

Your code looks ok in general.
ConfigFactory.load("resource.config") will handle a missing resource like an empty resource. As a result you get an empty Config. So, a try-catch-block does not really make sense.
You would usually specify a fallback configuration like this:
val appProps = ConfigFactory.load(
"application.properties"
).withFallBack(
ConfigFactory.load()
)
EDIT:
The sentence
As a result you get an empty Config
Is somewhat incomplete. ConfigFactory.load(resourceBaseName: String) applies defaultReference() and defaultOverrides(). So your resulting Config object probably contains some generic environment data and is not empty.
As far as I can see, your best option to check if the resource is there and emit an error message if not, is to look up the resource yourself:
val configFile = "application.properties"
val config = Option(getClass.getClassLoader.getResource(configFile)).fold {
println(s"Config not found!")
ConfigFactory.load()
} { resource =>
ConfigFactory.load(configFile)
}