!7

import javax.management.MBeanServer;

import java.lang.management.ManagementFactory;

import com.sun.management.HotSpotDiagnosticMXBean;

// This is the name of the HotSpot Diagnostic MBean

private static final String HOTSPOT_BEAN_NAME =

     "com.sun.management:type=HotSpotDiagnostic";

// field to store the hotspot diagnostic MBean 

private static volatile HotSpotDiagnosticMXBean hotspotMBean;

/**

 \* Call this method from your application whenever you 

 \* want to dump the heap snapshot into a file.

 \*

 \* @param fileName name of the heap dump file

 \* @param live flag that tells whether to dump

 \*             only the live objects

 \*/

static void dumpHeap(String fileName, boolean live) {

    // initialize hotspot diagnostic MBean

    initHotspotMBean();

    try {

        new File(fileName).delete();

        hotspotMBean.dumpHeap(fileName, live);

    } catch (RuntimeException re) {

        throw re;

    } catch (Exception exp) {

        throw new RuntimeException(exp);

    }

}

// initialize the hotspot diagnostic MBean field

private static void initHotspotMBean() {

    if (hotspotMBean == null) {

        synchronized (main.class) {

            if (hotspotMBean == null) {

                hotspotMBean = getHotspotMBean();

            }

        }

    }

}

// get the hotspot diagnostic MBean from the

// platform MBean server

private static HotSpotDiagnosticMXBean getHotspotMBean() {

    try {

        MBeanServer server = ManagementFactory.getPlatformMBeanServer();

        HotSpotDiagnosticMXBean bean = 

            ManagementFactory.newPlatformMXBeanProxy(server,

            HOTSPOT_BEAN_NAME, HotSpotDiagnosticMXBean.class);

        return bean;

    } catch (RuntimeException re) {

        throw re;

    } catch (Exception exp) {

        throw new RuntimeException(exp);

    }

}

p {

  // default heap dump file name

  String fileName = prepareProgramFile("heap.bin").getAbsolutePath();

  // by default dump only the live objects

  boolean live = true;

  // simple command line options

  switch (args.length) {

      case 2:

          live = args[1].equals("true");

      case 1:

          fileName = args[0];

  }

  // dump the heap

  dumpHeap(fileName, live);

  print("Saved: " + fileName + " (" + fileLength(fileName) + " bytes)");

  print("If you have jhat, you can now run:");

  print("  jhat " + bashQuote(fileName));

  print("...and then go to localhost:7000 in the browser.");

}