From bf6bc2c12a12ae481f9cca91fde446bdfd1967df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fabian=20St=C3=A4ber?= <fabian@fstab.de>
Date: Mon, 22 Jan 2024 13:49:45 +0100
Subject: [PATCH] Fix flaky JVM Thread metrics test (#915)
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Signed-off-by: Fabian Stäber <fabian@fstab.de>
---
 .../metrics/instrumentation/jvm/JvmThreadsMetricsTest.java   | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java
index 7be7892a9..94cadc268 100644
--- a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java
+++ b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmThreadsMetricsTest.java
@@ -108,8 +108,9 @@ public void testIgnoredMetricNotScraped() {
     @Test
     public void testInvalidThreadIds() {
         try {
-            int javaVersion = Integer.parseInt(System.getProperty("java.version"));
-            if (javaVersion >= 21) {
+            String javaVersion = System.getProperty("java.version"); // Example: "21.0.2"
+            String majorJavaVersion = javaVersion.replaceAll("\\..*", ""); // Example: "21"
+            if (Integer.parseInt(majorJavaVersion) >= 21) {
                 // With Java 21 and newer you can no longer have invalid thread ids.
                 return;
             }