jmap -dump:[live],format=b,file=<file-path> <pid>

live:- This parameter is optional. If set, it prints all those objects that 
have active references.

format = b , which means the heap dump file is in binary format. It is not necessary 
to set this parameter.

file =<file-path> indicates where the heap dump file will be generated.

<pid> :- process id of the java process

jps

ps -eaf| grep java

**jcmd <pid> GC.heap_dump <file-path>
<pid> - Process id of java process
<file-path> - Path where the heap dump is to be generated**

**-XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=<file-path>**

**// Java Program Invoking heapDump() Method of MBean Object

// Importing input output classes
import java.io.*;

// Main class
class GFG {

    // Custom string passed as input
    private static final String HOTSPOT_BEAN
        = "com.sun.management:type=HotSpotDiagnostic";

    // Private member variable of this class
    private static volatile Object hotSpotMBean;

    // Invoke this method when heap dump is to be generated
    // @param fileName - name of the heap dump file
    // @param live - indicates if only live objects are to
    // be included in the heap dump

    // Method 1
    // To generate heap dumps
    static void generateHeapDump(String fileName,
                                 boolean live)
    {
        initHotspotMBean();

        // Try block to check if any exceptions occurs
        try {

            Class clazz = Class.forName(
                "com.sun.management.HotSpotDiagnosticMXBean");
            Method m = clazz.getMethod(
                "dumpHeap", String.class, boolean.class);
            m.invoke(hotSpotMBean, fileName, live);
        }

        // Catch block handling runtime exceptions
        catch (RuntimeException re) {
            throw re;
        }
        catch (Exception exp) {
            throw new RuntimeException(exp);
        }
    }

    // Method 2
    private static void initHotspotMBean()
    {

        if (hotSpotMBean == null) {
            synchronized (JavaHeapDump.class)
            {

                if (hotSpotMBean == null) {
                    hotSpotMBean = getHotSpotMbean();
                }
            }
        }
    }

    // Method 3
    // To get the HOtSpotBean from the MBean server
    private static Object getHotSpotMbean()
    {

        Object hotspotBean = null;

        // Try block tocheck for exceptions
        try {

            // Loading using .forName() method
            Class clazz = Class.forName(
                "com.sun.management.HotSpotDiagnosticMXBean");

            MBeanServer mbeanServer
                = ManagementFactory
                      .getPlatformMBeanServer();

            hotspotBean
                = ManagementFactory.newPlatformMXBeanProxy(
                    mbeanServer, HOTSPOT_BEAN, clazz);

            return hotspotBean;
        }

        // Catch block 1
        // Handling exceptions if class not found
        catch (ClassNotFoundException e) {

            // Printthe exception along with line number
            // using printStackTrace() method
            e.printStackTrace();
        }

        // Catch block 2
        // Handling basic I/O exceptions
        catch (IOException e) {

            // Printthe exception along with line number
            // using printStackTrace() method
            e.printStackTrace();
        }

        return hotspotBean;
    }

    // Method 4
    // Main driver method
    public static void main(String[] args)
    {

        // File taken as an input
        String fileName
            = "/home/suchitra/Desktop/suchitra/projects/java-concurrency-examples/JavaHeapDumpGenerator/src/heap1.hprof";

        // Flag variable set to true
        boolean live = true;

        // Switch case
        switch (args.length) {
        case 2:
            live = args[1].equals("true");
        case 1:
            fileName = args[0];
        }

        // Calling Method 1 in main() method to
        // generate heap dumps
        generateHeapDump(fileName, live);
    }
}**