Deprecate OpenCensus shim public API

[LarryHu0217]

Summary

• deprecate the OpenCensus shim public entry points in line with the specification
• add module and package guidance directing users toward OpenTelemetry APIs
• suppress deprecation warnings only in tests that exercise the legacy shim API

This does not change runtime behavior or define the post-deprecation maintenance policy discussed in the issue.

Fixes #8673

Testing

• ./gradlew :opencensus-shim:spotlessApply :opencensus-shim:check
• ./gradlew :opencensus-shim:build

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.62%. Comparing base (bc956bc) to head (d0f9df6).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8674      +/-   ##
============================================
+ Coverage     91.47%   91.62%   +0.15%     
+ Complexity    10465    10327     -138     
============================================
  Files          1021     1003      -18     
  Lines         27694    27138     -556     
  Branches       3247     3187      -60     
============================================
- Hits          25333    24866     -467     
+ Misses         1617     1566      -51     
+ Partials        744      706      -38     

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[LarryHu0217]

The Windows Java 17 job failed during Gradle configuration because Maven Central returned HTTP 429 while resolving Kotlin 2.3.21, before project compilation started. All other OS/JDK builds, both GraalVM builds, CodeQL, API checks, coverage, links, and EasyCLA passed. I do not have permission to rerun the upstream workflow; could a maintainer rerun the failed jobs when convenient?

[opentelemetry-pr-dashboard]

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Waiting on reviewers · refreshed 2026-08-03 22:27 UTC

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[jack-berg]

Couple of small comments. Thanks!

[jack-berg]

For the deprecation messages, can you follow the pattern used in the deprecated ZipkinExporter? I.e. link to the spec PR where opencensus was deprecated and indicate that we stop publishing the artifact after June 2027. Use this updated message consistently in all places.

[LarryHu0217]

Addressed in dc333b8. All six deprecation notices now follow the linked specification pattern, reference open-telemetry/opentelemetry-specification#5138, and state that the artifact will no longer be published after June 2027. The targeted shim check and Javadoc task pass locally.

[LarryHu0217]

/dashboard route:reviewers

[opentelemetry-pr-dashboard]

@LarryHu0217 routed this pull request to reviewers.

[jack-berg]

Can you also update the artifact table in the root README.md to indicate that the opencensus is entry. Check out the opentracing entry for an example: https://github.com/open-telemetry/opentelemetry-java/blame/bc956bcf7d402104fe59af8ba31ff9b73849e9b7/README.md#L146

(Sorry meant to include this comment with my initial review but apparently I forgot to hit the submit button)

[LarryHu0217]

Addressed in d0f9df6. The root artifact table now marks the OpenCensus shim as deprecated, matching the OpenTracing entry. The spotless and opencensus-shim checks pass locally.