Replace platform threads with virtual threads to fix busy-waiting

[Kaaldut8]

Refactors busy-waiting loops by replacing platform threads with virtual threads and improving concurrency handling across affected components.

Fixes #2977

[github-actions]

PR Summary

Refactors busy-wait loops by replacing platform threads with virtual threads to improve concurrency handling and avoid busy-wait scenarios. Includes formatting enforcement via Spotless across modules, minor formatting tweaks in several modules, and updates to the session-server to use a virtual-thread-based scheduler for session expiration. Also adds license headers to rate-limiting-pattern sources and expands test file formatting for consistency across the project.

Changes

File	Summary
combinator/src/test/java/com/iluwatar/combinator/FinderTest.java	Adjusted the FinderTest multi-line string literal formatting to improve readability and align with the project’s formatting rules.
microservices-self-registration/contextservice/pom.xml	Added Spotless Maven plugin to enforce consistent Java formatting in the contextservice module.
microservices-self-registration/eurekaserver/pom.xml	Added Spotless Maven plugin to enforce consistent Java formatting in the Eurekaserver module.
microservices-self-registration/eurekaserver/src/main/java/com/learning/eurekaserver/EurekaserverApplication.java	Adjusted indentation and formatting of the EurekaserverApplication main method for consistency.
microservices-self-registration/eurekaserver/src/test/java/com/learning/eurekaserver/EurekaserverApplicationTests.java	Improved formatting and comments in the Eurekaserver application tests to match style guidelines.
microservices-self-registration/greetingservice/pom.xml	Added Spotless Maven plugin to enforce formatting in the greetingservice module.
microservices-self-registration/pom.xml	Enabled Spotless formatting checks at the parent module level to enforce consistency across modules.
pom.xml	Simplified Spotless configuration by removing explicit executions and relying on default googleJavaFormat settings.
rate-limiting-pattern/pom.xml	Inserted MIT license header into the rate-limiting-pattern module’s POM to clarify licensing.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/AdaptiveRateLimiter.java	Prepended MIT license header to AdaptiveRateLimiter.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java	Adjusted App main to correctly instantiate TokenBucketRateLimiter and added license header.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/FindCustomerRequest.java	Prepended MIT license header to FindCustomerRequest.java.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/FixedWindowRateLimiter.java	Prepended MIT license header to FixedWindowRateLimiter.java.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/RateLimitException.java	Prepended MIT license header to RateLimitException.java.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/RateLimitOperation.java	Prepended MIT license header to RateLimitOperation.java.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/RateLimiter.java	Prepended MIT license header to RateLimiter.java.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/ServiceUnavailableException.java	Prepended MIT license header to ServiceUnavailableException.java.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/ThrottlingException.java	Prepended MIT license header to ThrottlingException.java.
rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiter.java	Refactored TokenBucketRateLimiter: added shutdown, per-bucket lastRefillTime, synchronized tryConsume, and refillIfNeeded to support safe token replenishment and thread-safe consumption.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/AdaptiveRateLimiterTest.java	Prepended MIT license header to AdaptiveRateLimiterTest.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/AppTest.java	Prepended MIT license header to AppTest.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/AppTestUtils.java	Prepended MIT license header to AppTestUtils.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/ConcurrencyTests.java	Prepended MIT license header to ConcurrencyTests.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/ExceptionTests.java	Prepended MIT license header to ExceptionTests.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/FindCustomerRequestTest.java	Prepended MIT license header to FindCustomerRequestTest.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/FixedWindowRateLimiterTest.java	Prepended MIT license header to FixedWindowRateLimiterTest.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/RateLimitOperationTest.java	Prepended MIT license header to RateLimitOperationTest.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/RateLimiterTest.java	Prepended MIT license header to RateLimiterTest.
rate-limiting-pattern/src/test/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiterTest.java	Prepended MIT license header to TokenBucketRateLimiterTest.
server-session/src/main/java/com/iluwatar/sessionserver/App.java	Replaced thread-based session expiration checker with a virtual-thread-based scheduled task and added a shutdown hook; uses a virtual-thread scheduler.

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autogenerated by presubmit.ai

[github-actions]

✅ LGTM!

Review Summary

Commits Considered (1)

• ea68115: Apply Spotless formatting

Files Processed (2)

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java (3 hunks)
• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiter.java (2 hunks)

Actionable Comments (0)

Skipped Comments (8)

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java [1-25]

  maintainability: "License header added"

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java [89-93]

  maintainability: "Initialize TokenBucketRateLimiter outside try for proper cleanup"

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java [107-109]

  maintainability: "Ensure TokenBucketRateLimiter is shutdown to avoid thread leaks"

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiter.java [66-68]

  maintainability: "Expose shutdown for the rate limiter's scheduler"

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiter.java [74-75]

  design: "Track last refill timestamp for per-second refill policy"

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiter.java [79-80]

  maintainability: "Initialize refill timestamp during bucket construction"

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiter.java [82-91]

  concurrency: "Make token consumption synchronized and refilling lazy via refillIfNeeded"

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/TokenBucketRateLimiter.java [93-99]

  behavior: "Periodic refill for tokens based on elapsed time"

[github-actions]

🚨 Pull request needs attention.

Review Summary

Commits Considered (1)

• 90b794b: Removes expression which is always true

Files Processed (1)

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java (2 hunks)

Actionable Comments (2)

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java [89-89]

  possible bug: "Initialize rate limiter variable outside try."

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java [91-91]

  possible bug: "Potential risk of null after initialization."

Skipped Comments (1)

• rate-limiting-pattern/src/main/java/com/iluwatar/rate/limiting/pattern/App.java [1-24]

  maintainability: "Add license header to App.java."

[github-actions]

TokenBucketRateLimiter tb = null;

[github-actions]

tb = new TokenBucketRateLimiter(2, 1);

[github-actions]

✅ LGTM!

Review Summary

Commits Considered (1)

• 6d3356e: Add test coverage for sessionserver App

Files Processed (0)

Actionable Comments (0)

Skipped Comments (0)

[sonarqubecloud]

Quality Gate failed

Failed conditions
79.4% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud