From df39e74cdb5c65d7c1775ac3a14e9cb1e3e124ea Mon Sep 17 00:00:00 2001
From: Jun Luo <4catcode@gmail.com>
Date: Tue, 21 Apr 2026 11:05:56 +0800
Subject: [PATCH] chore: bump Java/Kotlin toolchain to JDK 21

Modernizes the build toolchain to the current LTS. The published SDK
jar is unchanged: compileJava now pins 'options.release = 8' so the
emitted bytecode and the API surface stay JDK 8 compatible.
---
 build.gradle.kts | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/build.gradle.kts b/build.gradle.kts
index ab6c0d2a8..91412af2b 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -16,12 +16,14 @@ version = "2.2.3"
 
 java {
     toolchain {
-        languageVersion = JavaLanguageVersion.of(8)
+        // Tests and Kotlin compilation use JDK 21. The published SDK jar
+        // still targets JDK 8 bytecode via `options.release = 8` below.
+        languageVersion = JavaLanguageVersion.of(21)
     }
 }
 
 kotlin {
-    jvmToolchain(8)
+    jvmToolchain(21)
 }
 
 repositories {
@@ -145,6 +147,7 @@ tasks {
 
     compileJava {
         options.encoding = "UTF-8"
+        options.release = 8
     }
 
     compileTestJava {