import java.io.UnsupportedEncodingException;

        checkForUnsupportedOptions(args);

        // the chosen option

        // one.

            usage(0);

        // Next we check the parameter count.

        if (paramCount != 1) {

        String pid = args[1];

        // Here we handle the built-in options

        // As more options are added we should create an abstract tool class and

        // have a table to map the options

        if (option.equals("-histo")) {

            histo(pid, "");

        } else if (option.startsWith("-histo:")) {

            histo(pid, option.substring("-histo:".length()));

        } else if (option.startsWith("-dump:")) {

            dump(pid, option.substring("-dump:".length()));

        } else if (option.equals("-finalizerinfo")) {

            executeCommandForPid(pid, "jcmd", "GC.finalizer_info");

        } else if (option.equals("-clstats")) {

            executeCommandForPid(pid, "jcmd", "GC.class_stats");

          usage(1);

    private static void executeCommandForPid(String pid, String command, Object ... args)

        throws AttachNotSupportedException, IOException,

               UnsupportedEncodingException {

        VirtualMachine vm = VirtualMachine.attach(pid);

        // Cast to HotSpotVirtualMachine as this is an

        // implementation specific method.

        HotSpotVirtualMachine hvm = (HotSpotVirtualMachine) vm;

        try (InputStream in = hvm.executeCommand(command, args)) {

          // read to EOF and just print output

          byte b[] = new byte[256];

          int n;

          do {

              n = in.read(b);

              if (n > 0) {

                  String s = new String(b, 0, n, "UTF-8");

                  System.out.print(s);

              }

          } while (n > 0);

        }

        vm.detach();

    }

    private static void histo(String pid, String options)

        throws AttachNotSupportedException, IOException,

               UnsupportedEncodingException {

        String liveopt = "-all";

        if (options.equals("") || options.equals("all")) {

            //  pass

        else if (options.equals("live")) {

            liveopt = "-live";

        else {

        // inspectHeap is not the same as jcmd GC.class_histogram

        executeCommandForPid(pid, "inspectheap", liveopt);

    private static void dump(String pid, String options)

        throws AttachNotSupportedException, IOException,

               UnsupportedEncodingException {

        String subopts[] = options.split(",");

        String filename = null;

        String liveopt = "-all";

        for (int i = 0; i < subopts.length; i++) {

            String subopt = subopts[i];

            if (subopt.equals("live")) {

                liveopt = "-live";

            } else if (subopt.startsWith("file=")) {

                // file=<file> - check that <file> is specified

                if (subopt.length() > 5) {

                    filename = subopt.substring(5);

                }

            }

        }

        // dumpHeap is not the same as jcmd GC.heap_dump

        executeCommandForPid(pid, "dumpheap", filename, liveopt);

    private static void checkForUnsupportedOptions(String[] args) {

        // Check arguments for -F, -m, and non-numeric value

        // and warn the user that SA is not supported anymore

        int paramCount = 0;

        for (String s : args) {

            if (s.equals("-F")) {

                SAOptionError("-F option used");

            }

            if (s.equals("-heap")) {

                SAOptionError("-heap option used");

            }

            /* Reimplemented using jcmd, output format is different

               from original one

            if (s.equals("-clstats")) {

                warnSA("-clstats option used");

            }

            if (s.equals("-finalizerinfo")) {

                warnSA("-finalizerinfo option used");

            }

            */

            if (! s.startsWith("-")) {

                if (! s.matches("[0-9]+")) {

                    SAOptionError("non PID argument");

                paramCount += 1;

        if (paramCount > 1) {

            SAOptionError("More than one non-option argument");

    private static void SAOptionError(String msg) {

        System.err.println("Error: " + msg);

        System.err.println("Cannot connect to core dump or remote debug server. Use jhsdb jmap instead");

        System.exit(1);

        System.err.println("    jmap -clstats <pid>");

        System.err.println("        to connect to running process and print class loader statistics");

        System.err.println("    jmap -finalizerinfo <pid>");

        System.err.println("        to connect to running process and print information on objects awaiting finalization");

        System.err.println("    jmap -histo[:live] <pid>");

        System.err.println("        to connect to running process and print histogram of java object heap");

        System.err.println("        if the \"live\" suboption is specified, only count live objects");

        System.err.println("    jmap -dump:<dump-options> <pid>");

        System.err.println("        to connect to running process and dump java heap");

        System.err.println("");

        System.err.println("    dump-options:");

        System.err.println("      live         dump only live objects; if not specified,");

        System.err.println("                   all objects in the heap are dumped.");

        System.err.println("      format=b     binary format");

        System.err.println("      file=<file>  dump heap to <file>");

        System.err.println("");

        System.err.println("    Example: jmap -dump:live,format=b,file=heap.bin <pid>");