MBean.md

MBean (Managed Bean) –

A MBean ia a managed java object, similar to a JavaBeans component,
that follows the design patterns mentioned in JMX specification.

An MBean can represent a device (printer etc.), an application, system objects,
service-oriented networks, or any resource, that needs to be managed

The JVM specification defines 5 types of MBean:

• Standard MBean
• Dynamic MBean
• Open MBean
• Model MBean
• MXBean

For Example:

Demonstration of a Standard Bean –

package com.thecodecache.mbeans;

/**
 * MBean
 * 
 * @author manoranjan.kumar
 */
public interface GameMBean {

	public void playFootball(String clubName);

	public String getPlayerName();

	public void setPlayerName(String playerName);
}

package com.thecodecache.mbeans;

public class Game implements GameMBean {

	private String playerName;

	@Override
	public void playFootball(String clubName) {
		System.out.println(this.playerName + " playing football for " + clubName);
	}

	@Override
	public String getPlayerName() {
		System.out.println("Return playerName " + this.playerName);
		return playerName;
	}

	@Override
	public void setPlayerName(String playerName) {
		System.out.println("Set playerName to value " + playerName);
		this.playerName = playerName;
	}
}

package com.thecodecache.mbeans;

import java.io.IOException;
import java.lang.management.ManagementFactory;

import javax.management.InstanceAlreadyExistsException;
import javax.management.MBeanRegistrationException;
import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.NotCompliantMBeanException;
import javax.management.ObjectName;

/**
 * JMX Agent
 * 
 * @author manoranjan.kumar
 */
public class Main {

	public static void main(String[] args) {
		System.out.println("main entry point");
		try {
			ObjectName objectName = new ObjectName("com.thecodecache.mbeans:type=basic,name=game");
			MBeanServer server = ManagementFactory.getPlatformMBeanServer();
			server.registerMBean(new Game(), objectName);
		} catch (MalformedObjectNameException | InstanceAlreadyExistsException | MBeanRegistrationException
				| NotCompliantMBeanException e1) {
			System.out.println("Exception Caught !!");
			e1.printStackTrace();
		}

		int code;
		try {
			code = System.in.read(); // to stop the JVM from exit so that we could troubleshoot
			System.out.println("user entered exit code: " + code);
		} catch (IOException e) {
			e.printStackTrace();
		}
		System.out.println("Exit!");
	}
}

Open up the JConsole from the JDK /bin installation directory –

Eclipse Standard Console –

Eclipse Standard Console –

Reference:

1. https://www.baeldung.com/java-management-extensions