i'm having some java interop issues with `@Throws`...

# announcements

[changd]

i'm having some java interop issues with @Throws

The API

interface StormcrowBase {
   @get:Throws(Exception::class)
   val featureNames: ArrayList<String>
}

Java call site

try {
                features = stormcrowBase.getFeatureNames();
            } catch (Exception e) {
                e.printStackTrace();
            }

The error I'm getting is Exception is never thrown in the corresponding block.

Any ideas?

[LeoColman]

What happens if you don't use get:@Throws and use @Throws instead?

[Shawn]

that’s a compile error

[changd]

yea, i haven't been able to resolve this. I switched from val to fun and the Java interop is working.. but the Kotlin API is pretty ugly now.

@Throws(Exception::class)
   fun getFeatureNames(): ArrayList<String>

Funny enough, the java generated decompiled class for both val and fun look identical

[LeoColman]

Throwing RuntimeExceptions is the rule for Java in a long long time

[LeoColman]

Why do you need @Throws anyway?

[changd]

i obfuscated some of the code ^^, this is to interop with our existing Java codebase

[changd]

Throwing RuntimeExceptions is the rule for Java in a long long time

i've never heard that

[LeoColman]

I understand, but does your Java code base requires you to catch exception always?

[LeoColman]

i've never heard that

Clean code establishes that throwing checked exception is bad, and throwing RuntimeException is better, as you don't need to catch them everywhere, unless required

[changd]

this is a pretty large refactor, changing ~100 call sites

[changd]

there are different use cases

[changd]

i suppose i could just write this interface in Java instead

[LeoColman]

But you can still catch an exception, even if it's Unchecked, right?

[LeoColman]

Perhaps refactoring isn't very good indeed

[LeoColman]

For this case

[LeoColman]

But consider throwing unchecked exceptions in the future

[changd]

we're writing all new code in Kotlin, and also this is for Android.. i think generally in Java-Android world, we prefer checked exceptions

[LeoColman]

As an Android dev myself, my team have always prefered to use unchecked exceptions. The same clean code practices should be applied

[LeoColman]

But this discussion is not the point here tho

[LeoColman]

I agree, maybe this interface can be written in Java

[changd]

thanks for the suggestions

[changd]

now if only there's Kotlin -> Java conversion 😄

[LeoColman]

I think there is tho

[LeoColman]

Try searching with CTRL SHIFT A