fix test assertion after changing log format

Author: SylvainJuge

jmx-scraper/src/integrationTest/java/io/opentelemetry/contrib/jmxscraper/JmxConnectionTest.java

@@ -86,17 +86,23 @@ private static void connectionTest(
   private static void checkConnectionLogs(JmxScraperContainer scraper, boolean expectedOk) {
 
     String[] logLines = scraper.getLogs().split("\n");
-    String lastLine = logLines[logLines.length - 1];
-
-    if (expectedOk) {
-      assertThat(lastLine)
-          .describedAs("should log connection success")
-          .endsWith("JMX connection test OK");
-    } else {
-      assertThat(lastLine)
-          .describedAs("should log connection failure")
-          .endsWith("JMX connection test ERROR");
-    }
+
+    // usually only the last line can be checked, however when it fails with an exception
+    // the stack trace is last in the output, so it's simpler to check all lines of log output
+
+    assertThat(logLines)
+        .anySatisfy(
+            line -> {
+              if (expectedOk) {
+                assertThat(line)
+                    .describedAs("should log connection success")
+                    .contains("JMX connection test OK");
+              } else {
+                assertThat(line)
+                    .describedAs("should log connection failure")
+                    .contains("JMX connection test ERROR");
+              }
+            });
   }
 
   private static void waitTerminated(GenericContainer<?> container) {