fullthreaddump.java

一个小公司要求给写的很简单的任务管理系统。

/*
 * @(#)FullThreadDump.java	1.5 05/11/17
 * 
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 * 
 * -Redistribution 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 Sun Microsystems, Inc. or the names of contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL 
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST 
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, 
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY 
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, 
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */

/*
 * @(#)FullThreadDump.java	1.5 05/11/17
 */

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>");
    }
}