Fix/Disable JMX & JNDI tests on JDK 16+

Author: sbrannen

spring-context/src/test/java/org/springframework/jmx/support/JmxUtilsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,6 @@
 
 import javax.management.DynamicMBean;
 import javax.management.MBeanServer;
-import javax.management.MBeanServerFactory;
 import javax.management.MalformedObjectNameException;
 import javax.management.NotCompliantMBeanException;
 import javax.management.ObjectName;
@@ -32,6 +31,7 @@
 import org.springframework.jmx.IJmxTestBean;
 import org.springframework.jmx.JmxTestBean;
 import org.springframework.jmx.export.TestDynamicMBean;
+import org.springframework.util.MBeanTestUtils;
 import org.springframework.util.ObjectUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -41,6 +41,7 @@
  *
  * @author Rob Harrop
  * @author Juergen Hoeller
+ * @author Sam Brannen
  */
 class JmxUtilsTests {
 
@@ -131,10 +132,11 @@ void locatePlatformMBeanServer() {
 		MBeanServer server = null;
 		try {
 			server = JmxUtils.locateMBeanServer();
+			assertThat(server).isNotNull();
 		}
 		finally {
 			if (server != null) {
-				MBeanServerFactory.releaseMBeanServer(server);
+				MBeanTestUtils.releaseMBeanServer(server);
 			}
 		}
 	}

spring-context/src/test/java/org/springframework/jndi/JndiLocatorDelegateTests.java

@@ -21,21 +21,25 @@
 import javax.naming.spi.NamingManager;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledForJreRange;
 
 import static org.assertj.core.api.Assertions.assertThat;
-
-
+import static org.junit.jupiter.api.condition.JRE.JAVA_16;
 
 /**
  * Tests for {@link JndiLocatorDelegate}.
  *
  * @author Phillip Webb
  * @author Juergen Hoeller
+ * @author Sam Brannen
  */
-public class JndiLocatorDelegateTests {
+@DisabledForJreRange(
+	min = JAVA_16,
+	disabledReason = "Cannot use reflection to set private static field in javax.naming.spi.NamingManager")
+class JndiLocatorDelegateTests {
 
 	@Test
-	public void isDefaultJndiEnvironmentAvailableFalse() throws Exception {
+	void isDefaultJndiEnvironmentAvailableFalse() throws Exception {
 		Field builderField = NamingManager.class.getDeclaredField("initctx_factory_builder");
 		builderField.setAccessible(true);
 		Object oldBuilder = builderField.get(null);

spring-context/src/test/java/org/springframework/util/MBeanTestUtils.java

@@ -34,21 +34,15 @@
 public class MBeanTestUtils {
 
 	/**
-	 * Resets {@link MBeanServerFactory} to a known consistent state. This involves
-	 * releasing all currently registered MBeanServers.
+	 * Reset the {@link MBeanServerFactory} to a known consistent state. This involves
+	 * {@linkplain #releaseMBeanServer(MBeanServer) releasing} all currently registered
+	 * MBeanServers.
 	 * <p>On JDK 8 - JDK 16, this method also resets the platformMBeanServer field
 	 * in {@link ManagementFactory} to {@code null}.
 	 */
 	public static synchronized void resetMBeanServers() throws Exception {
 		for (MBeanServer server : MBeanServerFactory.findMBeanServer(null)) {
-			try {
-				MBeanServerFactory.releaseMBeanServer(server);
-			}
-			catch (IllegalArgumentException ex) {
-				if (!ex.getMessage().contains("not in list")) {
-					throw ex;
-				}
-			}
+			releaseMBeanServer(server);
 		}
 
 		if (!isCurrentJreWithinRange(JRE.JAVA_16, JRE.OTHER)) {
@@ -58,6 +52,23 @@ public static synchronized void resetMBeanServers() throws Exception {
 		}
 	}
 
+	/**
+	 * Attempt to release the supplied {@link MBeanServer}.
+	 * <p>Ignores any {@link IllegalArgumentException} thrown by
+	 * {@link MBeanServerFactory#releaseMBeanServer(MBeanServer)} whose error
+	 * message contains the text "not in list".
+	 */
+	public static void releaseMBeanServer(MBeanServer server) {
+		try {
+			MBeanServerFactory.releaseMBeanServer(server);
+		}
+		catch (IllegalArgumentException ex) {
+			if (!ex.getMessage().contains("not in list")) {
+				throw ex;
+			}
+		}
+	}
+
 	static boolean isCurrentJreWithinRange(JRE min, JRE max) {
 		return EnumSet.range(min, max).contains(JRE.currentVersion());
 	}