import java.awt.Container;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryMXBean;
import java.lang.management.MemoryUsage;
import java.text.DecimalFormat;
import java.util.Timer;
import java.util.TimerTask;

import javax.swing.JFrame;
import javax.swing.JLabel;

public class MemoryMXBeanTest {
    private MemoryMXBean mbean;

    private JLabel heapLabel;
    private JLabel nonheapLabel;
    private MemoryUsageGraph heapGraph;
    private MemoryUsageGraph nonheapGraph;
    
    private DecimalFormat format;

    private final static String HEAP = " Heap ";
    private final static String NON_HEAP = " Non Heap ";
    private final static double TRANS_B_TO_M = 1024.0 * 1024.0;
    private final static double TRANS_B_TO_K = 1024.0;

    public MemoryMXBeanTest() {
        mbean = ManagementFactory.getMemoryMXBean();
        MemoryUsage heapUsage = null;
        MemoryUsage nonHeapUsage = null;
        synchronized (mbean) {
            heapUsage = mbean.getHeapMemoryUsage();
            nonHeapUsage = mbean.getNonHeapMemoryUsage();
        }

        heapGraph = new MemoryUsageGraph();
        heapGraph.setMemoryUsage(heapUsage);

        nonheapGraph = new MemoryUsageGraph();
        nonheapGraph.setMemoryUsage(nonHeapUsage);

        format = new DecimalFormat("0.00");

        initView();

        Timer timer = new Timer();
        timer.schedule(new TimerTask() {
                public void run() {
                    updateView();
                }
            }, 0, 500L);
    }

    private void initView() {
        JFrame frame = new JFrame("Memory Infomation");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Container container = frame.getContentPane();
        container.setLayout(new CompactGridLayout(0, 1));

        heapLabel = new JLabel(HEAP);
        container.add(heapLabel);
        container.add(heapGraph);

        nonheapLabel = new JLabel(NON_HEAP);
        container.add(nonheapLabel);
        container.add(nonheapGraph);

        frame.pack();
        frame.setVisible(true);
    }

    private void updateView() {
        MemoryUsage heapUsage = null;
        MemoryUsage nonHeapUsage = null;
        synchronized (mbean) {
            heapUsage = mbean.getHeapMemoryUsage();
            nonHeapUsage = mbean.getNonHeapMemoryUsage();
        }
        

        heapGraph.setMemoryUsage(heapUsage);
        heapLabel.setText(createLabelText(HEAP, heapUsage));


        nonheapGraph.setMemoryUsage(nonHeapUsage);
        nonheapLabel.setText(createLabelText(NON_HEAP, nonHeapUsage));
    }

    private String createLabelText(String pre, MemoryUsage usage) {
        StringBuilder builder = new StringBuilder();
        builder.append(pre);
        builder.append("(");

        double max = usage.getMax();
        if (max > 2000000L) {
            max /= TRANS_B_TO_M;
            builder.append(format.format(max));
            builder.append("M, ");
        } else {
            max /= TRANS_B_TO_K;
            builder.append(format.format(max));
            builder.append("K, ");
        }

        double committed = usage.getCommitted();
        if (committed > 2000000L) {
            committed /= TRANS_B_TO_M;
            builder.append(format.format(committed));
            builder.append("M): ");
        } else {
            committed /= TRANS_B_TO_K;
            builder.append(format.format(committed));
            builder.append("K): ");
        }

        double used = usage.getUsed();
        if (used > 2000000L) {
            used /= TRANS_B_TO_M;
            builder.append(format.format(used));
            builder.append("M");
        } else {
            used /= TRANS_B_TO_K;
            builder.append(format.format(used));
            builder.append("K");
        }

        return builder.toString();
    }

    public static void main(String[] args) {
        new MemoryMXBeanTest();
    }
}