GH-38024: [Java][FlightRPC] Expose appMetadata through JDBC ResultSet

[aiguofer]

FlightInfo can now contain appMetadata. This PR exposes that metadata through the JDBC interface through ArrowFlightJdbcFlightStreamResultSet.getAppMetadata.

• Closes: [Java][flight-sql-jdbc] Expose app_metadata for FlightInfo through JDBC interfaces #38024

[github-actions]

⚠️ GitHub issue #38024 has been automatically assigned in GitHub to PR creator.

[lidavidm]

CC @jduo

One question: we distribute shaded driver JARs, so people will have to reference a shaded name. It may be better to define a non-shaded interface that people can cast to?

[jduo]

CC @jduo

One question: we distribute shaded driver JARs, so people will have to reference a shaded name. It may be better to define a non-shaded interface that people can cast to?

I agree. Also, it would be good to have a non-shaded build target to reduce the binary size for users that aren't concerned about dependency collisions (for example, embedding the driver into a stack that they have full control of the dependencies).

[lidavidm]

it would be good to have a non-shaded build target to reduce the binary size for users that aren't concerned about dependency collisions

flight-sql-jdbc-core should do that and is distributed: https://central.sonatype.com/artifact/org.apache.arrow/flight-sql-jdbc-core/overview

[aiguofer]

Interesting. I seem to be able to cast it just fine when using the shaded jar. That being said, I agree having some sort of ArrowFlightSqlResultSet or some more relatable name would be better.

[lidavidm]

Ah, yes, the shaded JAR should work fine - but you have to 'peek' into the shaded JAR and use the shaded name, right? It would be best to provide a 'normal' name for people to reference instead of some odd shaded thing

[lidavidm]

That said if you want to defer that we can just focus on this change here

[lidavidm]

Alright, we can add the interface if someone complains about having to use the mangled name.

[aiguofer]

@lidavidm hey! sorry just got back from a long vacation last night. I think this is fine for now.

I was thinking at some point we might want to expose a way to get the Arrow batches directly as well, and at that point we can reconsider the interface/class name.

[lidavidm]

Ah, sounds good.

And yes, some way to convert a ResultSet to an Arrow or ADBC interface would be a perfect way to slowly introduce Arrow to a JDBC-based application.

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 5 benchmarking runs that have been run so far on merge-commit b6a9f6b.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 4 possible false positives for unstable benchmarks that are known to sometimes produce them.