/*

 * Copyright (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

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 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/*

 * This source code is provided to illustrate the usage of a given feature

 * or technique and has been deliberately simplified. Additional steps

 * required for a production-quality application, such as security checks,

 * input validation and proper error handling, might not be present in

 * this sample code.

 */

/*

 */

import javax.management.*;

import javax.management.remote.*;

import java.io.IOException;

import java.net.MalformedURLException;

/**

 * This VerboseGC class demonstrates the capability to get

 * the garbage collection statistics and memory usage remotely.

 */

public class VerboseGC {

    private MBeanServerConnection server;

    private JMXConnector jmxc;

    public VerboseGC(String hostname, int port) {

        System.out.println("Connecting to " + hostname + ":" + port);

        // Create an RMI connector client and connect it to

        // the RMI connector server

        String urlPath = "/jndi/rmi://" + hostname + ":" + port + "/jmxrmi";

        connect(urlPath);

   }

   public void dump(long interval, long samples) {

        try {

            PrintGCStat pstat = new PrintGCStat(server);

            for (int i = 0; i < samples; i++) {

                pstat.printVerboseGc();

                try {

                    Thread.sleep(interval);

                } catch (InterruptedException e) {

                    System.exit(1);

                }

            }

        } catch (IOException e) {

            System.err.println("\nCommunication error: " + e.getMessage());

            System.exit(1);

        }

    }

    /**

     * Connect to a JMX agent of a given URL.

     */

    private void connect(String urlPath) {

        try {

            JMXServiceURL url = new JMXServiceURL("rmi", "", 0, urlPath);

            this.jmxc = JMXConnectorFactory.connect(url);

            this.server = jmxc.getMBeanServerConnection();

        } catch (MalformedURLException e) {

            // should not reach here

        } catch (IOException e) {

            System.err.println("\nCommunication error: " + e.getMessage());

            System.exit(1);

        }

    }

    public static void main(String[] args) {

        if (args.length < 1) {

            usage();

        }

        String hostname = "";

        int port = -1;

        long interval = 5000; // default is 5 second interval

        long mins = 5;

        for (String arg: args) {

            if (arg.startsWith("-")) {

                if (arg.equals("-h") ||

                    arg.equals("-help") ||

                    arg.equals("-?")) {

                    usage();

                } else if (arg.startsWith("-interval=")) {

                    try {

                        interval = Integer.parseInt(arg.substring(10)) * 1000;

                    } catch (NumberFormatException ex) {

                        usage();

                    }

                } else if (arg.startsWith("-duration=")) {

                    try {

                        mins = Integer.parseInt(arg.substring(10));

                    } catch (NumberFormatException ex) {

                        usage();

                    }

                } else {

                    // Unknown switch

                    System.err.println("Unrecognized option: " + arg);

                    usage();

                }

            } else {

                String[] arg2 = arg.split(":");

                if (arg2.length != 2) {

                    usage();

                }

                hostname = arg2[0];

                try {

                    port = Integer.parseInt(arg2[1]);

                } catch (NumberFormatException x) {

                    usage();

                }

                if (port < 0) {

                    usage();

                }

            }

        }

        // get full thread dump and perform deadlock detection

        VerboseGC vgc = new VerboseGC(hostname, port);

        long samples = (mins * 60 * 1000) / interval;

        vgc.dump(interval, samples);

    }

    private static void usage() {

        System.out.print("Usage: java VerboseGC <hostname>:<port> ");

        System.out.println(" [-interval=seconds] [-duration=minutes]");

    }

}