JmxPoller.java

/*
* JBoss, Home of Professional Open Source
* Copyright 2011 Red Hat Inc. and/or its affiliates and other
* contributors as indicated by the @author tags. All rights reserved.
* See the copyright.txt in the distribution for a full listing of
* individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.infinispan.visualizer.poller.jmx;

import java.io.IOException;
import java.util.Map;

import javax.management.MBeanServerConnection;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

import org.infinispan.visualizer.poller.Poller;

/**
 * @param <T>
 * @author <a href="mailto:rtsang@redhat.com">Ray Tsang</a>
 */
public abstract class JmxPoller<T> implements Poller<T> {
   private volatile boolean connected = false;

   private final JMXServiceURL jmxUrl;
   private final Map<String, Object> jmxEnv;

   private JMXConnector connector;

   private MBeanServerConnection connection;

   public JmxPoller(JMXServiceURL jmxUrl, Map<String, Object> jmxEnv) {
      this.jmxUrl = jmxUrl;
      this.jmxEnv = jmxEnv;
   }

   public MBeanServerConnection getConnection() {
      return connection;
   }

   public void setConnection(MBeanServerConnection connection) {
      this.connection = connection;
   }

   @Override
   public void init() {
      try {
         connect();
      } catch (Exception e) {
         e.printStackTrace();
      }
   }

   abstract protected T doPoll() throws Exception;

   @Override
   public T poll() {
      try {
         if (!connected) {
            connect();
         }
         return doPoll();
      } catch (Exception e) {
         disconnect();
         e.printStackTrace();
         return null;
      }
   }

   protected void connect() throws Exception {
      System.out.println("Connecting to jmxUrl:'" + jmxUrl + "', jmxEnv:'" + jmxEnv + "'");
      connector = JMXConnectorFactory.connect(jmxUrl, jmxEnv);
      connection = connector.getMBeanServerConnection();
      connected = true;
   }

   protected void disconnect() {
      if (connector != null) {
         try {
            connector.close();
         } catch (IOException e) {
         }
      }
      connected = false;
   }

   @Override
   public void destroy() {
      disconnect();
   }
}