Forbid wildcard imports with Spotless

[AlexeyKuznetsov-DD]

What Does This Do

Configures Spotless to remove unused Java imports and reject wildcard imports across the repository. All existing wildcard imports are expanded to explicit imports.

The PR is intentionally split into two commits to simplify review:

1. Forbid wildcard imports with Spotless contains the six build and formatter configuration files. It applies forbidWildcardImports() to the main build, the standalone dependency-validation build, and both Java buildSrc projects. It also preserves the localized Netty 3.8 GrEclipse compatibility override.
2. Expand existing wildcard imports contains the existing source-formatting output: 173 Java, Scala, Groovy, or source-fixture files, including the complete explicit imports required by the Spring Boot JPA smoke application and the JSP source fixture.

Motivation

Wildcard imports obscure the dependencies used by a source file and conflict with the repository's import conventions. The lightweight built-in Spotless check prevents new wildcard imports; if one is introduced, spotlessCheck reports it and the developer can replace it with explicit imports.

Automatic expandWildcardImports() was evaluated first, but it is too memory-greedy for this repository. The step constructs JavaParser symbol solvers from each source-set classpath, and heap analysis showed those solver graphs retained across thousands of Spotless formatter instances until an 8 GiB Gradle heap was exhausted. The final implementation therefore uses forbidWildcardImports() rather than automatic expansion.

Additional Notes

Netty 3.8 uses the current GrEclipse formatter locally because the repository-wide GrEclipse 4.27 pin cannot format those tests. The localized override and its generated compatibility formatting can be removed after that pin is lifted. See diffplug/spotless#3013.

The centralized Spotless setup follows the existing formatter configuration introduced and updated in #12208.

Validation:

• ./gradlew spotlessCheck writeMainVersionFile --rerun-tasks --parallel --max-workers=4
• ./gradlew :dd-java-agent:agent-debugger:debugger-el:test --tests com.datadog.debugger.el.expressions.HasAnyExpressionTest
• ./gradlew :dd-java-agent:agent-tooling:test --tests datadog.trace.agent.tooling.stratum.StratumManagerTest (2 tests)
• ./gradlew :dd-smoke-tests:apm-tracing-disabled:bootJar
• ./gradlew :dd-smoke-tests:springboot-jpa:bootWar
• ./gradlew -p buildSrc :call-site-instrumentation-plugin:spotlessCheck
• ./gradlew -p buildSrc :modifiable-config-agent:spotlessCheck :modifiable-config-agent:build
• ./gradlew -p test-published-dependencies spotlessCheck
• ./gradlew -p test-published-dependencies :agent-logs-on-java-7:compileTestJava
• Negative probes confirmed wildcard imports fail the built-in Spotless check in the main build and standalone builds
• Repository scan found zero remaining Java wildcard imports outside generated build output
• Stable patch comparison confirmed the rewritten source-formatting commit is identical to its previously reviewed version

Contributor Checklist

• Format the title according to the contribution guidelines
• Assign the type: and (comp: or inst:) labels in addition to any other useful labels
• Avoid using close, fix, or any linking keywords when referencing an issue
  Use solves instead, and assign the PR milestone to the issue
• Update the CODEOWNERS file on source file addition, migration, or deletion
• Update public documentation with any new configuration flags or behaviors
• Once approved, use merge queue to merge the PR

Jira ticket: N/A

[chatgpt-codex-connector]

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[datadog-prod-us1-5]

The main build expands wildcard imports. Two separate Gradle builds still accept wildcard imports, so the repository-wide rule is incomplete.

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[jpbempel]

LGTM

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	14.92 s	14.74 s	[+0.2%; +2.2%] (maybe worse)
startup:insecure-bank:tracing:Agent	13.68 s	13.76 s	[-1.5%; +0.2%] (no difference)
startup:petclinic:appsec:Agent	17.44 s	17.23 s	[+0.3%; +2.2%] (maybe worse)
startup:petclinic:iast:Agent	16.81 s	17.46 s	[-7.8%; +0.4%] (no difference)
startup:petclinic:profiling:Agent	17.24 s	17.37 s	[-1.9%; +0.4%] (no difference)
startup:petclinic:sca:Agent	17.53 s	17.27 s	[+0.5%; +2.6%] (maybe worse)
startup:petclinic:tracing:Agent	16.53 s	16.57 s	[-1.1%; +0.6%] (no difference)

Commit: 403c9945 · CI Pipeline · Benchmarking Platform UI

---

Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.

[pr-commenter]

Debugger benchmarks

Parameters

	Baseline	Candidate
baseline_or_candidate	baseline	candidate
ci_job_date	1787354928	1787355255
end_time	2026-08-21T23:30:19	2026-08-21T23:35:46
git_branch	master	alexeyk/spotless-expand-imports
git_commit_sha	710bee5	7bcf2ef
start_time	2026-08-21T23:28:49	2026-08-21T23:34:16

See matching parameters

	Baseline	Candidate
ci_job_id	1974461279	1974461279
ci_pipeline_id	132530959	132530959
cpu_model	Intel(R) Xeon(R) Platinum 8175M CPU @ 2.50GHz	Intel(R) Xeon(R) Platinum 8175M CPU @ 2.50GHz
git_commit_date	1787354316	1787354316

Summary

Found 0 performance improvements and 0 performance regressions! Performance is the same for 10 metrics, 5 unstable metrics.

See unchanged results

scenario	Δ mean agg_http_req_duration_min	Δ mean agg_http_req_duration_p50	Δ mean agg_http_req_duration_p75	Δ mean agg_http_req_duration_p99	Δ mean throughput
scenario:noprobe	unstable [-20.694µs; +27.806µs] or [-6.249%; +8.397%]	unstable [-31.690µs; +37.275µs] or [-8.700%; +10.233%]	unstable [-40.352µs; +48.109µs] or [-10.669%; +12.719%]	unstable [-52.476µs; +137.047µs] or [-4.613%; +12.048%]	same
scenario:basic	same	same	same	unstable [-162.329µs; +42.605µs] or [-16.660%; +4.372%]	same
scenario:loop	same	same	same	same	same

Request duration reports for reports

gantt
    title reports - request duration [CI 0.99] : candidate=None, baseline=None
    dateFormat X
    axisFormat %s
section baseline
noprobe (364.269 µs) : 334, 395
.   : milestone, 364,
basic (343.482 µs) : 337, 350
.   : milestone, 343,
loop (8.113 ms) : 8050, 8177
.   : milestone, 8113,
section candidate
noprobe (367.061 µs) : 332, 402
.   : milestone, 367,
basic (343.997 µs) : 337, 351
.   : milestone, 344,
loop (8.114 ms) : 8050, 8178
.   : milestone, 8114,

Loading

• baseline results

Scenario	Request median duration [CI 0.99]
noprobe	364.269 µs [333.562 µs, 394.976 µs]
basic	343.482 µs [336.983 µs, 349.98 µs]
loop	8.113 ms [8.05 ms, 8.177 ms]

• candidate results

Scenario	Request median duration [CI 0.99]
noprobe	367.061 µs [332.412 µs, 401.711 µs]
basic	343.997 µs [337.027 µs, 350.966 µs]
loop	8.114 ms [8.05 ms, 8.178 ms]

[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: c9ec832e8c

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• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

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[datadog-prod-us1-5]

More details

The formatter rules apply consistently across the main and separate Gradle builds. The source edits contain import changes and adjacent whitespace only.

Was this helpful? React 👍 or 👎

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[pr-commenter]

Kafka / producer-benchmark

Parameters

	Baseline	Candidate
baseline_or_candidate	baseline	candidate
git_branch	master	alexeyk/spotless-expand-imports
git_commit_date	1787314937	1787355846
git_commit_sha	926e82f	403c994

See matching parameters

	Baseline	Candidate
ci_job_date	1787357403	1787357403
ci_job_id	1974484356	1974484356
ci_pipeline_id	132532272	132532272
cpu_model	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
jdkVersion	11.0.31	11.0.31
jmhVersion	1.36	1.36
jvm	/usr/lib/jvm/java-11-openjdk-amd64/bin/java	/usr/lib/jvm/java-11-openjdk-amd64/bin/java
jvmArgs	-Dhttp.proxyHost=127.0.0.1 -Dhttp.proxyPort=15002 -Dhttps.proxyHost=127.0.0.1 -Dhttps.proxyPort=15002 -Dhttp.nonProxyHosts=localhost	*.localhost
kernel_version	Linux runner-zfyrx7zua-project-304-concurrent-1-ajzkvqbz 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux	Linux runner-zfyrx7zua-project-304-concurrent-1-ajzkvqbz 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
vmName	OpenJDK 64-Bit Server VM	OpenJDK 64-Bit Server VM
vmVersion	11.0.31+11-post-1ubuntu1-22.04.2-Ubuntu	11.0.31+11-post-1ubuntu1-22.04.2-Ubuntu

Summary

Found 0 performance improvements and 0 performance regressions! Performance is the same for 3 metrics, 0 unstable metrics.

See unchanged results

scenario	Δ mean throughput
scenario:not-instrumented/KafkaProduceBenchmark.benchProduce	same
scenario:only-tracing-dsm-disabled-benchmarks/KafkaProduceBenchmark.benchProduce	same
scenario:only-tracing-dsm-enabled-benchmarks/KafkaProduceBenchmark.benchProduce	same

[mhlidd]

Nice changes!

[datadog-prod-us1-5]

The new rule does not cover buildSrc/modifiable-config-agent. A wildcard import can enter that Java project without a Spotless error.

_{Open Bits AI session}

_{🤖 Datadog Autotest · Commit a576807 · What is Autotest? · @DataDog review to ask questions · Any feedback? Reach out in #autotest}

[pr-commenter]

Kafka / consumer-benchmark

Parameters

	Baseline	Candidate
baseline_or_candidate	baseline	candidate
git_branch	master	alexeyk/spotless-expand-imports
git_commit_date	1787314937	1787355846
git_commit_sha	926e82f	403c994

See matching parameters

	Baseline	Candidate
ci_job_date	1787357021	1787357021
ci_job_id	1974484357	1974484357
ci_pipeline_id	132532272	132532272
cpu_model	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
jdkVersion	11.0.31	11.0.31
jmhVersion	1.36	1.36
jvm	/usr/lib/jvm/java-11-openjdk-amd64/bin/java	/usr/lib/jvm/java-11-openjdk-amd64/bin/java
jvmArgs	-Dhttp.proxyHost=127.0.0.1 -Dhttp.proxyPort=15002 -Dhttps.proxyHost=127.0.0.1 -Dhttps.proxyPort=15002 -Dhttp.nonProxyHosts=localhost	*.localhost
kernel_version	Linux runner-zfyrx7zua-project-304-concurrent-0-irsreu3v 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux	Linux runner-zfyrx7zua-project-304-concurrent-0-irsreu3v 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
vmName	OpenJDK 64-Bit Server VM	OpenJDK 64-Bit Server VM
vmVersion	11.0.31+11-post-1ubuntu1-22.04.2-Ubuntu	11.0.31+11-post-1ubuntu1-22.04.2-Ubuntu

Summary

Found 0 performance improvements and 1 performance regressions! Performance is the same for 2 metrics, 0 unstable metrics.

scenario	Δ mean throughput
scenario:not-instrumented/KafkaConsumerBenchmark.benchConsume	worse [-13570.181op/s; -3969.474op/s] or [-4.589%; -1.342%]

See unchanged results

scenario	Δ mean throughput
scenario:only-tracing-dsm-disabled-benchmarks/KafkaConsumerBenchmark.benchConsume	same
scenario:only-tracing-dsm-enabled-benchmarks/KafkaConsumerBenchmark.benchConsume	same