Migrate build tools and example projects to Java 17 and add compatibility fixes

[shai-almog]

Motivation

• Move the example multi-module project and CI/local tooling to Java 17 so sources and tests using modern language features compile and run.
• Avoid opaque failures during local iOS builds by aligning the request java.version with the Maven compiler target when they differ.
• Provide minimal compatibility stubs for StringConcatFactory to satisfy Java API expectations in the VM/Ports sources.

Description

• Updated GitHub Actions workflow to set up JDK 17 using actions/setup-java@v4 for the macOS iOS build job.
• Added StringConcatFactory stub classes under Ports/CLDC11 and vm/JavaAPI to avoid missing-symbol issues for string concat support.
• Enhanced the Maven plugin (CN1BuildMojo) to parse Java version strings via a new parseJavaVersion helper and to override the build request java.version when maven.compiler.target is higher than the request, logging the change.
• Added the same parseJavaVersion helper and used it in InstallCn1libsMojo to robustly compare library and project codename1.arg.java.version values.
• Updated sample hellocodenameone project and module pom.xml files to target Java 17 (maven.compiler.source / target and project properties), and updated top-level properties to java.version=17 and test compile targets.
• Modified various scripts and wrappers (mvnw, mvnw.cmd, build.sh, run.sh, build.bat, run.bat, build-ios-app.sh) to prefer or locate a JDK 17 installation and to set JAVA_HOME/PATH for Maven invocations; build-ios-app.sh switches JAVA_HOME to JAVA17_HOME for iOS Maven builds.
• Added Java17LanguageFeaturesTest to the example common tests to validate typical Java 17 language constructs compile in tests, and updated the example README to note Java 17 usage.

Testing

• No existing automated CI test runs are included in this change; a new test Java17LanguageFeaturesTest was added to the example project to exercise Java 17 language features (compilation assertion).
• The changes are limited to build tooling, example project configuration, and small API stubs; integration/CI verification is expected to run in normal pipeline execution after merge.

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Codex Task

[github-actions]

✅ Continuous Quality Report

Test & Coverage

• ✅ Tests: 2314 total, 0 failed, 0 skipped
• 📊 Line coverage: 53.16% [HTML preview] [Download]
  • Lowest covered classes
    • com.codename1.ui.Display$EdtException – 0.00%
    • com.codename1.ui.plaf.CSSBorder$LinearGradient – 0.00%
    • com.codename1.util.EasyThread$InQueueRunnable – 0.00%
    • com.codename1.components.FloatingActionButton$ReleaseActionListener – 0.00%
    • com.codename1.io.Oauth2$RefreshTokenActionListener – 0.00%
    • com.codename1.util.EasyThread$RunAndWaitRunnable – 0.00%
    • com.codename1.components.ToastBar$FlushAnimationCallback – 0.00%
    • com.codename1.ui.plaf.CSSBorder$ColorStop – 0.00%
    • com.codename1.ui.ElevationComparator – 0.00%
    • com.codename1.ui.spinner.TimeSpinner3D$MinuteRowFormatter – 0.00%

Static Analysis

• SpotBugs [HTML preview] [Download]
  • ❌ ByteCodeTranslator: 97 findings (High: 2, Normal: 68, Low: 27)
    • Top findings
      • High: com/codename1/tools/translator/BytecodeMethod.java:559 – Method com.codename1.tools.translator.BytecodeMethod.findWritableFields(Set) seems to be useless (rule: UC_USELESS_VOID_METHOD)
      • High: com/codename1/tools/translator/bytecodes/TryCatch.java:75 – Write to static field com.codename1.tools.translator.bytecodes.TryCatch.hasTryCatch from instance method com.codename1.tools.translator.bytecodes.TryCatch.appendInstruction(StringBuilder, List) (rule: ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD)
      • Normal: com/codename1/tools/translator/ByteCodeClass.java:1791 – com.codename1.tools.translator.ByteCodeClass.getBaseClassObject() may expose internal representation by returning ByteCodeClass.baseClassObject (rule: EI_EXPOSE_REP)
      • …and 94 more
  • ❌ android: 412 findings (High: 24, Normal: 196, Low: 192)
    • Top findings
      • High: CodenameOne/src/com/codename1/impl/CodenameOneThread.java:48 – com.codename1.impl.CodenameOneThread.STACK_FRAME_SIZE isn't final but should be (rule: MS_SHOULD_BE_FINAL)
      • High: com/codename1/impl/android/AndroidImplementation.java:1067 – Write to static field com.codename1.impl.android.AndroidImplementation.context from instance method com.codename1.impl.android.AndroidImplementation.setContext(Context) (rule: ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD)
      • High: com/codename1/impl/android/AndroidImplementation.java:1268 – com.codename1.impl.android.AndroidImplementation.isDarkMode() has Boolean return type and returns explicit null (rule: NP_BOOLEAN_RETURN_NULL)
      • …and 409 more
  • ❌ codenameone-maven-plugin: 477 findings (High: 1, Normal: 313, Low: 163)
    • Top findings
      • High: com/codename1/maven/AbstractCN1Mojo.java:807 – com.codename1.maven.AbstractCN1Mojo.OS isn't final but should be (rule: MS_SHOULD_BE_FINAL)
      • Normal: com/codename1/builders/AndroidGradleBuilder.java:1018 – Dead store to googleServicesJson in com.codename1.builders.AndroidGradleBuilder.build(File, BuildRequest) (rule: DLS_DEAD_LOCAL_STORE)
      • Normal: com/codename1/builders/AndroidGradleBuilder.java:1043 – Possible null pointer dereference in com.codename1.builders.AndroidGradleBuilder.build(File, BuildRequest) due to return value of called method (rule: NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE)
      • …and 474 more
  • ❌ core-unittests: 1 findings (Normal: 1)
    • Top findings
      • Normal: CodenameOne/src/com/codename1/ui/util/MutableResource.java:239 – com.codename1.ui.util.MutableResource.saveL10N(DataOutputStream, Hashtable) makes inefficient use of keySet iterator instead of entrySet iterator (rule: WMI_WRONG_MAP_ITERATOR)
  • ❌ ios: 125 findings (High: 4, Normal: 75, Low: 46)
    • Top findings
      • High: com/codename1/impl/ios/IOSImplementation.java:1223 – com.codename1.impl.ios.IOSImplementation.isDarkMode() has Boolean return type and returns explicit null (rule: NP_BOOLEAN_RETURN_NULL)
      • High: com/codename1/impl/ios/IOSImplementation.java:128 – com.codename1.impl.ios.IOSImplementation.nativeInstance isn't final but should be (rule: MS_SHOULD_BE_FINAL)
      • High: com/codename1/impl/ios/IOSImplementation.java:214 – Write to static field com.codename1.impl.ios.IOSImplementation.instance from instance method com.codename1.impl.ios.IOSImplementation.init(Object) (rule: ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD)
      • …and 122 more
• ✅ PMD: 0 findings (no issues) [Report archive]
• ✅ Checkstyle: 0 findings (no issues) [Report archive]

Generated automatically by the PR CI workflow.

[shai-almog]

Compared 32 screenshots: 32 matched.

Native Android coverage

• 📊 Line coverage: 7.30% (3711/50862 lines covered) [HTML preview] (artifact android-coverage-report, jacocoAndroidReport/html/index.html)
  • Other counters: instruction 5.65% (18066/319659), branch 2.76% (858/31113), complexity 3.40% (1010/29741), method 5.98% (828/13853), class 9.63% (176/1827)
  • Lowest covered classes
    • kotlin.collections.kotlin.collections.ArraysKt___ArraysKt – 0.00% (0/6327 lines covered)
    • kotlin.collections.unsigned.kotlin.collections.unsigned.UArraysKt___UArraysKt – 0.00% (0/2384 lines covered)
    • org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.ClassReader – 0.00% (0/1519 lines covered)
    • kotlin.collections.kotlin.collections.CollectionsKt___CollectionsKt – 0.00% (0/1148 lines covered)
    • org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.MethodWriter – 0.00% (0/923 lines covered)
    • kotlin.sequences.kotlin.sequences.SequencesKt___SequencesKt – 0.00% (0/712 lines covered)
    • kotlin.text.kotlin.text.StringsKt___StringsKt – 0.00% (0/623 lines covered)
    • org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.Frame – 0.00% (0/564 lines covered)
    • kotlin.collections.kotlin.collections.ArraysKt___ArraysJvmKt – 0.00% (0/495 lines covered)
    • kotlinx.coroutines.kotlinx.coroutines.JobSupport – 0.00% (0/423 lines covered)

✅ Native Android screenshot tests passed.

Native Android coverage

• 📊 Line coverage: 7.30% (3711/50862 lines covered) [HTML preview] (artifact android-coverage-report, jacocoAndroidReport/html/index.html)
  • Other counters: instruction 5.65% (18066/319659), branch 2.76% (858/31113), complexity 3.40% (1010/29741), method 5.98% (828/13853), class 9.63% (176/1827)
  • Lowest covered classes
    • kotlin.collections.kotlin.collections.ArraysKt___ArraysKt – 0.00% (0/6327 lines covered)
    • kotlin.collections.unsigned.kotlin.collections.unsigned.UArraysKt___UArraysKt – 0.00% (0/2384 lines covered)
    • org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.ClassReader – 0.00% (0/1519 lines covered)
    • kotlin.collections.kotlin.collections.CollectionsKt___CollectionsKt – 0.00% (0/1148 lines covered)
    • org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.MethodWriter – 0.00% (0/923 lines covered)
    • kotlin.sequences.kotlin.sequences.SequencesKt___SequencesKt – 0.00% (0/712 lines covered)
    • kotlin.text.kotlin.text.StringsKt___StringsKt – 0.00% (0/623 lines covered)
    • org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.Frame – 0.00% (0/564 lines covered)
    • kotlin.collections.kotlin.collections.ArraysKt___ArraysJvmKt – 0.00% (0/495 lines covered)
    • kotlinx.coroutines.kotlinx.coroutines.JobSupport – 0.00% (0/423 lines covered)

[github-actions]

✅ ByteCodeTranslator Quality Report

Test & Coverage

• ✅ Tests: 146 total, 0 failed, 2 skipped

Benchmark Results

• Execution Time: 9676 ms

• Hotspots (Top 20 sampled methods):

  • 21.04% com.codename1.tools.translator.Parser.isMethodUsed (345 samples)
  • 19.45% java.lang.String.indexOf (319 samples)
  • 19.33% java.util.ArrayList.indexOf (317 samples)
  • 5.00% com.codename1.tools.translator.BytecodeMethod.addToConstantPool (82 samples)
  • 4.70% java.lang.Object.hashCode (77 samples)
  • 4.57% com.codename1.tools.translator.ByteCodeClass.calcUsedByNative (75 samples)
  • 2.74% java.lang.System.identityHashCode (45 samples)
  • 2.38% com.codename1.tools.translator.BytecodeMethod.optimize (39 samples)
  • 1.65% com.codename1.tools.translator.Parser.generateClassAndMethodIndexHeader (27 samples)
  • 1.28% com.codename1.tools.translator.Parser.cullMethods (21 samples)
  • 1.04% java.lang.StringBuilder.append (17 samples)
  • 0.79% com.codename1.tools.translator.BytecodeMethod.appendCMethodPrefix (13 samples)
  • 0.79% com.codename1.tools.translator.ByteCodeClass.markDependent (13 samples)
  • 0.79% com.codename1.tools.translator.BytecodeMethod.equals (13 samples)
  • 0.73% sun.nio.ch.FileDispatcherImpl.write0 (12 samples)
  • 0.61% sun.nio.fs.UnixNativeDispatcher.open0 (10 samples)
  • 0.61% java.lang.StringCoding.encode (10 samples)
  • 0.49% java.io.UnixFileSystem.getBooleanAttributes0 (8 samples)
  • 0.43% com.codename1.tools.translator.ByteCodeClass.updateAllDependencies (7 samples)
  • 0.43% java.io.FileOutputStream.writeBytes (7 samples)

• ⚠️ Coverage report not generated.

Static Analysis

• ✅ SpotBugs: no findings (report was not generated by the build).
• ⚠️ PMD report not generated.
• ⚠️ Checkstyle report not generated.

Generated automatically by the PR CI workflow.