!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.");
}