Ensure 304 response code does not throw exceptions

[Copilot]

This PR fixes an issue where HTTP 304 (Not Modified) responses would throw IllegalStateException when the response body is empty or null, similar to the previous fix for 204 responses.

Problem

When handling 304 responses with empty bodies, the current implementation would fail with:

java.lang.IllegalStateException: response is not eligible for a body and must not be closed
	at okhttp3.Response.close(Response.kt:302)
	at com.microsoft.kiota.http.OkHttpRequestAdapter.closeResponse(OkHttpRequestAdapter.java:348)

Solution

Applied the same pattern already established for 204 (No Content) responses to 304 (Not Modified) responses:

1. Updated shouldReturnNull() method to return true for 304 responses, ensuring they return null instead of attempting to parse empty content
2. Updated closeResponse() method to skip closing 304 responses, preventing the IllegalStateException
3. Extended existing tests to include 304 in the test cases that verify null responses for empty content

Changes Made

• Modified shouldReturnNull(): return statusCode == 204 || statusCode == 304;
• Modified closeResponse(): if (closeResponse && response.code() != 204 && response.code() != 304)
• Added 304 to existing test cases in OkHttpRequestAdapterTest

The changes are minimal and follow the exact same pattern as the existing 204 handling, ensuring consistency and maintainability.

Fixes #1848.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• graph.microsoft.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath18252088451007800667txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 4' (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath7775169814115159399txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 1' (dns block)
• www.google.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath18252088451007800667txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 4' (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath7775169814115159399txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 1' (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

---

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[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• graph.microsoft.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath6263530406976102149txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 1' (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath7185381649245087998txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 2' (dns block)
• www.google.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath6263530406976102149txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 1' (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -Dorg.gradle.internal.worker.tmpdir=/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/test/work -javaagent:/home/REDACTED/work/kiota-java/kiota-java/components/http/okHttp/build/tmp/.cache/expanded/zip_ff7bf8f04f99dc306508d1c81e47a68b/jacocoagent.jar=destfile=build/jacoco/test.exec,append=true,inclnolocationclasses=false,dumponexit=true,output=file,jmx=false @/home/REDACTED/.gradle/.tmp/gradle-worker-classpath7185381649245087998txt -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 2' (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
94.4% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud