Unnecessary `IOException` in `IonObjectMapper` method signatures

[mcliedtke]

With the move to RuntimeException's as a baseline in Jackson-3, there are some unnecessary throws IOException declarations in the method signatures of readValue and writeValue methods int he IonObjectMapper class. Could these throws declarations be removed?

There is one method - writeValueAsIonValue which technically does have an uncaught IOException, but given that it both opens and closes the writer to just in-memory objects, I don't see how an actual IOException would be anything other than an illegal state. I am not sure if there is a conventional way to handle this, but it would be nice to see this caught and rethrown as a RuntimeException base as well (is there a good corresponding JacksonException that fits? JacksonIOException?)

[cowtowncoder]

+1 if I understand this correctly: IOException should no longer be exposed by anything in 3.x.
I think src/main/java/tools/jackson/core/exc/JacksonIOException.java is indeed the thing that jackson-core (and format modules) use.

Due to signature change, not 100% sure if this can be done for 3.0(.2) or does it need to go in 3.1(.0).
But +1 for doing this.

[mcliedtke]

Let me know if this is roughly what is expected. #631

No strong opinions on 3.0(.2) vs. 3.1

[cowtowncoder]

No strong opinions on 3.0(.2) vs. 3.1

Right, that is more for me to consider, wrt compatibility. I think 3.1 it should be, so 3.x is the target branch to use.

[mcliedtke]

Thank you for the quick review and merge!

[cowtowncoder]

Thank you for pointing out that missing part of 3.0 code conversion & fix!