FullThreadDump.java

/*
 * 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
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/*
 * 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 FullThreadDump class demonstrates the capability to get
 * a full thread dump and also detect deadlock remotely.
 */
public class FullThreadDump {
    private MBeanServerConnection server;
    private JMXConnector jmxc;
    public FullThreadDump(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() {
        try {
            ThreadMonitor monitor = new ThreadMonitor(server);
            monitor.threadDump();
            if (!monitor.findDeadlock()) {
                System.out.println("No deadlock found.");
            }
        } 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[] arg2 = args[0].split(":");
        if (arg2.length != 2) {
            usage();
        }
        String hostname = arg2[0];
        int port = -1;
        try {
            port = Integer.parseInt(arg2[1]);
        } catch (NumberFormatException x) {
            usage();
        }
        if (port < 0) {
            usage();
        }

        // get full thread dump and perform deadlock detection
        FullThreadDump ftd = new FullThreadDump(hostname, port);
        ftd.dump();
    }

    private static void usage() {
        System.out.println("Usage: java FullThreadDump <hostname>:<port>");
    }
}