From 71fd4c4c0a80648d89a324efa264298692e4370d Mon Sep 17 00:00:00 2001
From: Jon Griffiths <jon_p_griffiths@yahoo.com>
Date: Thu, 28 May 2026 20:23:22 +1200
Subject: [PATCH] java: only set source level to 17 if supported by javac

---
 configure.ac | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index bf83da840..735a205bb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -422,7 +422,13 @@ AM_CONDITIONAL([HAVE_JAVAC], [test "x$JAVAC" != "x"])
 AM_CONDITIONAL([RUN_JAVA_TESTS],
     dnl Only run tests if we have java-swig, compiler and interpreter
     [test "x$tests" = xyes -a "x$swig_java" = xyes -a -n "$JAVAC" -a -n "$JAVA"])
-JAVAC_TARGET=17
+JAVAC_TARGET=8
+if test "x$JAVAC" != "x"; then
+    # Use source version 17 if supported
+    TMP_OUTPUT=$($JAVAC --source 17 --help)
+    AS_IF([test $? -eq 0], [JAVAC_TARGET=17],
+          [AC_MSG_NOTICE([Java source level set to fallback (8)])])
+fi
 AC_SUBST([JAVAC_TARGET])
 
 AC_SUBST([AM_CFLAGS])