DEV Community

loading...

Discussion on: Building a 22 Megabytes Microservice with Java, Javalin and GraalVM

Collapse
5422m4n profile image
Sven Assmann

I really dislike that there may always be runtime errors that GraalVM can't predict at compile time (correct me if i'm wrong).

I wonder how it is possible after compilation to encounter runtime errors? As I see it the compiler does the static type checks, so at runtime there shouldn't be any surprises. Do I overlook something?

Collapse
birdayz profile image
Johannes Brüderl Author • Edited

I quote from GraalVM docs:

SubstrateVM tries to resolve these elements through a static analysis that
detects calls to the reflection API. Where the analysis fails the program
elements reflectively accessed at run time must be specified 
during native image generation in a configuration file [...]

So yeah it's best-effort only, but no guarantee to detect your stuff. Reflection is a hacky side-step to manipulate or create objects etc, so no guarantees. Javac can't give you guarantees about runtime behavior of reflection, so GraalVM can't do it as well.

Forem Open with the Forem app