Test for the usage of ThreadMXBean

See -
eclipse-openj9/openj9#16694
javamelody/javamelody#1165

.gitignore

@@ -1,24 +1,38 @@
-# Compiled class file
-*.class
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
 
-# Log file
-*.log
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
 
-# BlueJ files
-*.ctxt
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
 
-# Mobile Tools for Java (J2ME)
-.mtj.tmp/
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
 
-# Package Files #
-*.jar
-*.war
-*.nar
-*.ear
-*.zip
-*.tar.gz
-*.rar
+### VS Code ###
+.vscode/
 
-# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
-hs_err_pid*
-replay_pid*
+### Mac OS ###
+.DS_Store

pom.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.example</groupId>
+    <artifactId>mvn-test</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <version>3.8.1</version>
+                    <configuration>
+                        <compilerArgs>
+                            <arg>--add-exports</arg>
+                            <arg>jdk.management/com.ibm.lang.management.internal=ALL-UNNAMED</arg>
+                        </compilerArgs>
+                    </configuration>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+    <dependencies>
+    </dependencies>
+</project>

src/main/java/BeanTester.java

@@ -0,0 +1,30 @@
+import com.ibm.lang.management.internal.ExtendedThreadMXBeanImpl;
+import com.sun.management.ThreadMXBean;
+
+import java.lang.management.ManagementFactory;
+
+public class BeanTester
+{
+    public static void main(String[] args)
+    {
+        System.out.println("Hello, World!");
+        ibmThreadMxBean();
+        sunThreadMxBean();
+    }
+
+    private static void ibmThreadMxBean()
+    {
+        System.out.println("IBM ThreadMXBean");
+        com.ibm.lang.management.ThreadMXBean ibmThreadBean = ExtendedThreadMXBeanImpl.getInstance();
+        System.out.printf("isThreadAllocatedMemorySupported : %s%n", ibmThreadBean.isThreadAllocatedMemorySupported());
+        System.out.printf("getThreadAllocatedBytes : %d%n", ibmThreadBean.getThreadAllocatedBytes(Thread.currentThread().getId()));
+    }
+
+    private static void sunThreadMxBean()
+    {
+        System.out.println("Sun ThreadMXBean");
+        ThreadMXBean sunThreadBean = (ThreadMXBean) ManagementFactory.getThreadMXBean();
+        System.out.printf("isThreadAllocatedMemorySupported : %s%n", sunThreadBean.isThreadAllocatedMemorySupported());
+        System.out.printf("getThreadAllocatedBytes : %d%n", sunThreadBean.getThreadAllocatedBytes(Thread.currentThread().getId()));
+    }
+}