[Feature][Flink] Define FlinkTableJob and FlinkStreamTableJob Java base classes

[ocb3916]

What is the purpose of the change

Implements Phase 0.2 of the Scala removal plan (#4408).

Defines FlinkTableJob and FlinkStreamTableJob as the Java abstract base classes that will
eventually replace the Scala FlinkTableTrait and FlinkStreamTableTrait traits — for Table API
(batch) jobs and jobs that mix the DataStream API with the Table API, respectively. Both classes
live in the existing streampark-flink-shims-base module and follow the same
ready → handle → destroy lifecycle established by FlinkStreamingJob in sub-issue 0.1, so all
three "Job" base classes share a consistent shape.

Brief change log

• Add FlinkTableJob abstract class with lifecycle: ready → handle → destroy, exposing the
  underlying TableEnvironment via getTableEnv() (composition) instead of extending / mimicking
  the interface like the legacy trait did
• Add FlinkStreamTableJob abstract class with the same lifecycle, exposing both
  StreamExecutionEnvironment (getEnv()) and StreamTableEnvironment (getTableEnv()) via
  composition
• Add sql(String) / sql(String, Consumer<String>) on both classes, bridging to the existing
  Scala FlinkSqlExecutor.executeSql so the public API surface stays Scala-free
• Add markConvertedToDataStream() on FlinkStreamTableJob, replacing the legacy trait's
  automatic Table → DataStream conversion detection (no longer possible under composition) with
  an explicit call
• Place both classes under org.apache.streampark.flink.core.javaapi rather than the
  issue-specified org.apache.streampark.flink.core.java — see note below
• Add JUnit 5 tests for both classes verifying lifecycle order, getTableEnv()/getEnv()
  composition, SQL execution, and the markConvertedToDataStream() flag
• Extract shared lifecycle/logic to fix SonarCloud duplication warnings:
  • AbstractFlinkJob (package-private) — common ready → handle → execute → destroy lifecycle, sql(...), and app.name lookup shared by both job classes
  • FlinkJobSupport — SQL callback bridging (Java Consumer <-> Scala Function1)
  • JobTestParams — shared ParameterTool builder used by both test classes
• Replace System.out.println with SLF4J logging in both execute(...) overrides

A note on the package name

The issue body specifies org.apache.streampark.flink.core.java. That name breaks Scala
compilation of every sibling file in streampark-flink-shims-base that references
java.util/java.io/java.lang — a nested package literally named java shadows the real
java.* standard library for any Scala file sharing the enclosing package. Reproduced both ways
in a clean build:

• org.apache.streampark.flink.core.java → BUILD FAILURE, 33 errors, all java.util/java.io/
  java.lang unresolved in unrelated sibling .scala files
• org.apache.streampark.flink.core.javaapi → BUILD SUCCESS, no other files affected

Went with javaapi for this PR. Open to other naming suggestions if javaapi isn't preferred.

Design note: composition instead of full delegation

The legacy traits extend/mimic Flink's TableEnvironment / StreamTableEnvironment directly,
re-implementing ~40-50 delegate methods each (FlinkStreamTableTrait additionally needed a
$-prefix naming hack to avoid clashes between the two APIs). The new classes hold the
environment(s) as fields instead, exposed via getTableEnv() / getEnv(). This removes the
delegate boilerplate and the naming hack, and means the classes won't go stale as the Flink Table
API changes — but it is a breaking change for code that currently calls Table API methods
directly on a trait instance (e.g. job.sqlQuery(...) → job.getTableEnv().sqlQuery(...)).
Flagging for discussion since the Phase 11 migration guide will need to cover it.

Verifying this change

mvn test -pl streampark-flink/streampark-flink-shims/streampark-flink-shims-base

Tests run: 9, Failures: 0, Errors: 0

Does this pull request potentially affect one of the following parts?

• The public API
• The web application
• The build system

Documentation

• Relates to issue [Proposal] Remove Scala from StreamPark — design and migration plan #4408
• Part of umbrella issue [Proposal] Remove Scala from StreamPark — design and migration plan #4408, sub-issue 0.2

[sonarqubecloud]

Quality Gate passed

Issues
5 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud