Display available free Swap memory using JMX

FreeSwap.java

package edu.self.nyg.example.jmx.app;

import java.lang.management.ManagementFactory;
import java.text.NumberFormat;
import java.util.Set;

import javax.management.MBeanServer;
import javax.management.ObjectInstance;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class FreeSwap {

    public static void main(String[] args) throws Exception {
        log.info("Application started");

        MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();
        log.info("MBean count: {}", mBeanServer.getMBeanCount());

        com.sun.management.OperatingSystemMXBean mbean = (com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();

        long freeMemory = mbean.getFreePhysicalMemorySize();
        long totalMemory = mbean.getTotalPhysicalMemorySize();

        long freeSwap = mbean.getFreeSwapSpaceSize();
        long totalSwap = mbean.getTotalSwapSpaceSize();

        log.info("Memory: {} / {}", format(freeMemory), format(totalMemory));
        log.info("Swap: {} / {}", format(freeSwap), format(totalSwap));

        Thread.sleep(Long.MAX_VALUE);
    }

    private static String format(long value) {
        return NumberFormat.getNumberInstance().format(value);
    }
}