BasicExample.java

package com.j256.simplejmx.example;

import com.j256.simplejmx.common.JmxAttributeField;
import com.j256.simplejmx.common.JmxAttributeMethod;
import com.j256.simplejmx.common.JmxOperation;
import com.j256.simplejmx.common.JmxResource;
import com.j256.simplejmx.server.JmxServer;

/**
 * Example program that was written to show off the basic features of SimpleJmx. It starts up a JMX server and registers
 * an object with the server. The object exposes field and method information as JMX attributes and operations using
 * annotations.
 * 
 * <p>
 * <b>NOTE:</b> For more details, see the SimpleJMX website: http://256stuff.com/sources/simplejmx/
 * </p>
 * 
 * @author graywatson
 */
public class BasicExample {

	private static final int JMX_PORT = 8000;

	public static void main(String[] args) throws Exception {
		new BasicExample().doMain(args);
	}

	private void doMain(String[] args) throws Exception {

		// create the object we will be exposing with JMX
		RuntimeCounter counter = new RuntimeCounter();

		// create a new JMX server listening on a specific port
		JmxServer jmxServer = new JmxServer(JMX_PORT);
		/*
		 * NOTE: you could also do:
		 * 
		 * JmxServer jmxServer = new JmxServer(ManagementFactory.getPlatformMBeanServer());
		 */

		try {
			// start our server
			jmxServer.start();

			// register our object
			jmxServer.register(counter);
			// we can register other objects here
			// jmxServer.register(someOtherObject);

			// do your other code here...
			// we just sleep forever to let the jmx server do its stuff
			System.out.println("Sleeping for a while to let the server do its stuff");
			System.out.println("JMX server on port " + JMX_PORT);
			Thread.sleep(1000000000);

		} finally {
			// unregister is not necessary if we are stopping the server
			jmxServer.unregister(counter);
			// close our server
			jmxServer.close();
		}
	}

	/**
	 * Here is our little bean that we are exposing via JMX. It can be in another class. It's just an inner class here
	 * for convenience. We could also specify folderNames array here to locate the inside of a folder for jconsole.
	 */
	@JmxResource(domainName = "j256.simplejmx", description = "Counter that shows how long we have been running")
	public static class RuntimeCounter {

		// start our timer
		private long startMillis = System.currentTimeMillis();

		// we can annotate fields directly to be published in JMX, isReadible defaults to true
		@JmxAttributeField(description = "Show runtime in seconds", isWritable = true)
		private boolean showSeconds;

		// we can annotate getter methods
		@JmxAttributeMethod(description = "Run time in seconds or milliseconds")
		public long getRunTime() {
			// show how long we are running
			long diffMillis = System.currentTimeMillis() - startMillis;
			if (showSeconds) {
				// as seconds
				return diffMillis / 1000;
			} else {
				// or as milliseconds
				return diffMillis;
			}
		}

		/*
		 * NOTE: there is no setRunTime(...) so it won't be writable.
		 */

		// this is an operation that shows up in the operations tab in jconsole.
		@JmxOperation(description = "Reset our start time to the current millis")
		public String resetStartTime() {
			startMillis = System.currentTimeMillis();
			return "Timer has been reset to current millis";
		}

		// this is an operation that shows up in the operations tab in jconsole.
		@JmxOperation(description = "Add a positive or negative offset to the start time milliseconds",
				parameterNames = { "offset in millis" },
				parameterDescriptions = { "offset milliseconds value to add to start time millis" })
		public String addToStartTime(long offset) {
			long old = startMillis;
			startMillis += offset;
			return "Timer value changed from " + old + " to " + startMillis;
		}
	}
}