From 8e0ff0d349abd274d8cb95c1ba5ca5397108b4ff Mon Sep 17 00:00:00 2001
From: "Flavio S. Glock" <flavio.glock@booking.com>
Date: Thu, 26 Mar 2026 16:00:11 +0100
Subject: [PATCH] fix: suppress fastjson2 Unsafe deprecation warnings on Java
 23+

Add --sun-misc-unsafe-memory-access=allow JVM option to suppress
warnings about fastjson2 using deprecated sun.misc.Unsafe methods.

These warnings appear on Java 23+ (JEP 471) when using JSON module:
  WARNING: sun.misc.Unsafe::arrayBaseOffset has been called by
  com.alibaba.fastjson2.util.JDKUtils

The flag is only added when Java version >= 23, since the option
does not exist in Java 22.

Updated both jperl (Unix) and jperl.bat (Windows) launchers.

Generated with [Devin](https://cli.devin.ai/docs)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---
 jperl     | 7 +++++++
 jperl.bat | 8 ++++++++
 2 files changed, 15 insertions(+)

diff --git a/jperl b/jperl
index fba4ff43c..e6bbd76c0 100755
--- a/jperl
+++ b/jperl
@@ -31,6 +31,13 @@ fi
 #   for native system calls (file operations, process management).
 JVM_OPTS="--enable-native-access=ALL-UNNAMED"
 
+# Java 23+ warns about sun.misc.Unsafe usage (JEP 471). Add flag to suppress
+# warnings from fastjson2 library.
+JAVA_VERSION=$(java -version 2>&1 | head -1 | sed 's/.*version "\([0-9]*\).*/\1/')
+if [ "$JAVA_VERSION" -ge 23 ] 2>/dev/null; then
+    JVM_OPTS="$JVM_OPTS --sun-misc-unsafe-memory-access=allow"
+fi
+
 # Note: Only include CLASSPATH if set, to avoid empty prefix that would add current dir to path
 if [ -n "$CLASSPATH" ]; then
     CP="$CLASSPATH:$JAR_PATH"
diff --git a/jperl.bat b/jperl.bat
index 72cd6885b..521af7b94 100755
--- a/jperl.bat
+++ b/jperl.bat
@@ -18,5 +18,13 @@ rem --enable-native-access=ALL-UNNAMED: Required by FFM (Foreign Function & Memo
 rem   for native system calls (file operations, process management).
 set JVM_OPTS=--enable-native-access=ALL-UNNAMED
 
+rem Java 23+ warns about sun.misc.Unsafe usage (JEP 471). Add flag to suppress
+rem warnings from fastjson2 library.
+for /f "tokens=3" %%v in ('java -version 2^>^&1 ^| findstr /i "version"') do (
+    for /f "tokens=1 delims=." %%m in ("%%~v") do (
+        if %%m GEQ 23 set JVM_OPTS=%JVM_OPTS% --sun-misc-unsafe-memory-access=allow
+    )
+)
+
 rem Launch Java
 java %JVM_OPTS% %JPERL_OPTS% -cp "%CLASSPATH%;%SCRIPT_DIR%target\perlonjava-5.42.0.jar" org.perlonjava.app.cli.Main %*