THRIFT-5919: Set JDK 17 as minimum Java version

[greggdonovan]

Summary

THRIFT-5919: Set JDK 17 as minimum Java version

Set JDK 17 as the minimum Java version for the Thrift Java library - Java 8 reached public EOL in March 2022 and Java 11 in September 2023. JDK 17 is the current baseline LTS version.

What changed

Code generation (t_java_generator.cc)

• Remove android_legacy, java5 generator flags
• Remove option_type=thrift support (throws error directing users to option_type=jdk8)
• option_type=jdk8 remains opt-in (default behavior unchanged: raw types, null for unset optional fields)
• Jakarta annotations (jakarta.annotation.Generated) are now the default; opt out with javax_annotations
• Generated code uses switch expressions and pattern matching instanceof
• Remove @Nullable annotations from generated code

Java library

• Delete org.apache.thrift.Option class (replaced by java.util.Optional)
• Delete lib/java/android/ (Android AAR build targeting SDK 23 / build tools 23.0.1)
• Modernize TBaseHelper, TUnion, protocol classes with pattern matching instanceof and switch expressions
• Fix PartialThriftComparer null comparison bug: when one object was null and the other non-null, returned UNKNOWN instead of NOT_EQUAL
• Add unwrapOptional() to PartialThriftComparer for Optional-wrapped field values

Build infrastructure

• Remove ant dependency; Gradle is the sole Java build system
• Remove manual Gradle download from CI; use gradle/actions/setup-gradle@v5
• Switch shadow plugin from abandoned com.github.johnrengelman.shadow 8.1.1 to com.gradleup.shadow 9.3.1
• Remove obsolete shadowRuntimeElements workaround (incompatible with new Shadow plugin)
• Upgrade Spotless 8.1.0 → 8.2.1, google-java-format pinned to 1.28.0 (latest that works with JDK17)
• Upgrade SpotBugs tool 4.5.3 → 4.9.8, FindSecBugs 1.12.0 → 1.14.0 (plugin stays at 5.2.5 due to upstream enum property issue)
• Upgrade PMD 6.0.0 → 7.9.0 with category-based rulesets
• Fix Gradle 10 deprecation warnings (assignment operators, tasks.register, @Inject ExecOperations)
• Refactor generateTestThrift.gradle: replace closure-based thriftCompile with ThriftGeneratorTask abstract class
• Remove jakarta_annotations from generator args in test thrift compilation (now default)

Dependencies

• SLF4J 1.7.36 → 2.0.17 (OSGi range narrowed to [2.0,3))
• HttpClient 5.2.1 → 5.4.1, HttpCore 5.2 → 5.3.1
• Servlet 5.0.0 → 6.1.0, Tomcat 10.1.4 → 11.0.2
• JUnit 5.9.1 → 5.11.4, Mockito 5.3.0 → 5.15.2
• javax.annotation 2.1.1 → 3.0.0 (jakarta.annotation-api)
• Replace slf4j-log4j12 with slf4j-simple for test runtime (log4j 1.x is EOL)
• commons-lang3 → 3.18.0

Kotlin

• Set JVM 17 target for all Kotlin modules (was JVM 1.8)
• Switch from kotlinx-coroutines-jdk8 to kotlinx-coroutines-core (jdk8 APIs merged into core since 1.7.0)
• Upgrade cross-test deps: SLF4J 2.0.17, Logback 1.5.28, HttpCore 4.4.16, HttpClient 4.5.14, kotlinx-coroutines-core 1.10.2

Other

• Remove ant from configure.ac Java detection
• Update contrib/thrift-maven-plugin/pom.xml compiler source/target from 1.8 to 17
• Dependabot: add labels and dependency groups for Java/Kotlin packages
• Remove lib/java/android/ from Makefile.am
• Flatten lib/java/CMakeLists.txt (remove if(ANDROID) branch)

Breaking Changes

See CHANGES.md for full details. Summary:

Change	Migration
Minimum Java version is JDK 17	Upgrade JDK
org.apache.thrift.Option deleted	Use java.util.Optional
option_type=thrift removed	Use option_type=jdk8 instead
Jakarta annotations are default	Use javax_annotations flag to opt out
android_legacy, java5 flags removed	Remove from --gen java: args
SLF4J 2.0+ required	Upgrade SLF4J dependency

POM diff vs published 0.22.0

All differences are intentional (version bump, dependency upgrades, new maven.compiler.release property):

--- libthrift-0.22.0.pom (Maven Central)
+++ libthrift-0.23.0-SNAPSHOT (this branch)
@@ version
-  <version>0.22.0</version>
+  <version>0.23.0-SNAPSHOT</version>
@@ new properties block
+  <properties>
+    <maven.compiler.release>17</maven.compiler.release>
+  </properties>
@@ dependency version upgrades
   slf4j-api:          1.7.36 → 2.0.17
   httpclient5:        5.2.1  → 5.4.1
   httpcore5:          5.2    → 5.3.1
   jakarta.servlet-api: 5.0.0 → 6.1.0
   jakarta.annotation-api: 2.1.1 → 3.0.0
   commons-lang3:      3.12.0 → 3.18.0

No structural changes — same <groupId>, <artifactId>, <name>, <description>, <url>, <licenses>, <developers>, <scm>, and <dependencies> layout.

Related JIRA Issues

• THRIFT-5644 - Upgrade to Java 17 in build env and upgrade minimal Java version to 11 (partially reverted by THRIFT-5702)
• THRIFT-5702 - Support Java 8 (reverted the minimum version bump)

Test plan

• CI green: all 3 workflows (Build, Build with CMake, MSVC Build) pass
• Verify generated code compiles with JDK 17
• Verify cross-test client/server work with Kotlin modules
• Verify --gen java:javax_annotations opt-out works
• Verify --gen java:option_type=jdk8 works (opt-in Optional wrapping)
• Verify --gen java:option_type=thrift fails with clear error message
• Verify generated POM matches published 0.22.0 structure (only version + dep upgrades differ)

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[greggdonovan]

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[greptile-apps]

Additional Comments (1)

lib/java/gradle/publishing.gradle
Shadow artifact may publish

This PR removed the withVariantsFromConfiguration(configurations.shadowRuntimeElements) { skip() } guard. With the Shadow plugin still applied, publishing can start including additional variants/artifacts (e.g., a shadow runtime variant) depending on plugin behavior, which would change what gets pushed to Maven compared to prior releases. If the intent is to keep publishing only the normal java component, please re-add an explicit exclusion for Shadow variants under the new plugin (or otherwise verify the published publication contents don’t change).