Remove confirmed unused Java code (#15358)
* Remove confirmed unused Java code
Remove validated unused helpers, constants, classes, and matching dedicated tests across Java modules.
Deprecate currently unused datasource mapper methods so downstream plugin usage can be confirmed before removal.
Validation:
- mvn spotless:check
- mvn -B clean compile apache-rat:check checkstyle:check spotbugs:check spotless:check -DskipTests
- mvn -B '-Prelease-nacos,!dev' clean install -Drat.skip=true -Dspotbugs.skip=true -Dcheckstyle.skip=true -DskipTests=false
- mvn -B clean install -Prelease-nacos -DskipTests=true
- mvn -B clean verify -Pintegration-test
- mvn -B -pl test/java-sdk-test clean verify -Pjava-sdk-integration-test -DskipTests=false
- mvn -B -pl test/maintainer-sdk-test clean verify -Pmaintainer-sdk-integration-test -DskipTests=false
Assisted-by: Codex
* Fix flaky unit test setup
Reuse the same version 0.2.0 tar.gz fixture bytes for digest validation and HTTP response payloads, and initialize EnvUtil in GlobalExecutorTest when the test runs without suite-level environment setup.
Assisted-by: Codex
* Fix config test isolation
Assisted-by: Claude Code
* Fix flaky failover reactor test
Assisted-by: Claude Code
杨翊 SionYang
1f9f6ccc8e