Java tutorial
/* * Copyright (c) 1995, 2008, 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 or 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 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Client.java - JMX client that interacts with the JMX agent. It gets * attributes and performs operations on the Hello MBean and the QueueSampler * MXBean example. It also listens for Hello MBean notifications. */ package com.example; import java.io.IOException; import java.util.Arrays; import java.util.Iterator; import java.util.Set; import java.util.TreeSet; import javax.management.AttributeChangeNotification; import javax.management.JMX; import javax.management.MBeanServerConnection; import javax.management.Notification; import javax.management.NotificationEmitter; import javax.management.NotificationListener; import javax.management.ObjectName; import javax.management.remote.JMXConnector; import javax.management.remote.JMXConnectorFactory; import javax.management.remote.JMXServiceURL; public class Client { /** * Inner class that will handle the notifications. */ public static class ClientListener implements NotificationListener { public void handleNotification(Notification notification, Object handback) { echo("\nReceived notification:"); echo("\tClassName: " + notification.getClass().getName()); echo("\tSource: " + notification.getSource()); echo("\tType: " + notification.getType()); echo("\tMessage: " + notification.getMessage()); if (notification instanceof AttributeChangeNotification) { AttributeChangeNotification acn = (AttributeChangeNotification) notification; echo("\tAttributeName: " + acn.getAttributeName()); echo("\tAttributeType: " + acn.getAttributeType()); echo("\tNewValue: " + acn.getNewValue()); echo("\tOldValue: " + acn.getOldValue()); } } } /* For simplicity, we declare "throws Exception". Real programs will usually want finer-grained exception handling. */ public static void main(String[] args) throws Exception { // Create an RMI connector client and // connect it to the RMI connector server // echo("\nCreate an RMI connector client and " + "connect it to the RMI connector server"); JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://:9999/jmxrmi"); JMXConnector jmxc = JMXConnectorFactory.connect(url, null); // Create listener // ClientListener listener = new ClientListener(); // Get an MBeanServerConnection // echo("\nGet an MBeanServerConnection"); MBeanServerConnection mbsc = jmxc.getMBeanServerConnection(); waitForEnterPressed(); // Get domains from MBeanServer // echo("\nDomains:"); String domains[] = mbsc.getDomains(); Arrays.sort(domains); for (String domain : domains) { echo("\tDomain = " + domain); } waitForEnterPressed(); // Get MBeanServer's default domain // echo("\nMBeanServer default domain = " + mbsc.getDefaultDomain()); // Get MBean count // echo("\nMBean count = " + mbsc.getMBeanCount()); // Query MBean names // echo("\nQuery MBeanServer MBeans:"); Set<ObjectName> names = new TreeSet<ObjectName>(mbsc.queryNames(null, null)); for (ObjectName name : names) { echo("\tObjectName = " + name); } waitForEnterPressed(); // ---------------------- // Manage the Hello MBean // ---------------------- echo("\n>>> Perform operations on Hello MBean <<<"); // Construct the ObjectName for the Hello MBean // ObjectName mbeanName = new ObjectName("com.example:type=Hello"); // Create a dedicated proxy for the MBean instead of // going directly through the MBean server connection // HelloMBean mbeanProxy = JMX.newMBeanProxy(mbsc, mbeanName, HelloMBean.class, true); // Add notification listener on Hello MBean // echo("\nAdd notification listener..."); mbsc.addNotificationListener(mbeanName, listener, null, null); // Get CacheSize attribute in Hello MBean // echo("\nCacheSize = " + mbeanProxy.getCacheSize()); // Set CacheSize attribute in Hello MBean // Calling "reset" makes the Hello MBean emit a // notification that will be received by the registered // ClientListener. // mbeanProxy.setCacheSize(150); // Sleep for 2 seconds to have time to receive the notification // echo("\nWaiting for notification..."); sleep(2000); // Get CacheSize attribute in Hello MBean // echo("\nCacheSize = " + mbeanProxy.getCacheSize()); // Invoke "sayHello" in Hello MBean // echo("\nInvoke sayHello() in Hello MBean..."); mbeanProxy.sayHello(); // Invoke "add" in Hello MBean // echo("\nInvoke add(2, 3) in Hello MBean..."); echo("\nadd(2, 3) = " + mbeanProxy.add(2, 3)); waitForEnterPressed(); // ------------------------------ // Manage the QueueSampler MXBean // ------------------------------ echo("\n>>> Perform operations on QueueSampler MXBean <<<"); // Construct the ObjectName for the QueueSampler MXBean // ObjectName mxbeanName = new ObjectName("com.example:type=QueueSampler"); // Create a dedicated proxy for the MXBean instead of // going directly through the MBean server connection // QueueSamplerMXBean mxbeanProxy = JMX.newMXBeanProxy(mbsc, mxbeanName, QueueSamplerMXBean.class); // Get QueueSample attribute in QueueSampler MXBean // QueueSample queue1 = mxbeanProxy.getQueueSample(); echo("\nQueueSample.Date = " + queue1.getDate()); echo("QueueSample.Head = " + queue1.getHead()); echo("QueueSample.Size = " + queue1.getSize()); // Invoke "clearQueue" in QueueSampler MXBean // echo("\nInvoke clearQueue() in QueueSampler MXBean..."); mxbeanProxy.clearQueue(); // Get QueueSample attribute in QueueSampler MXBean // QueueSample queue2 = mxbeanProxy.getQueueSample(); echo("\nQueueSample.Date = " + queue2.getDate()); echo("QueueSample.Head = " + queue2.getHead()); echo("QueueSample.Size = " + queue2.getSize()); waitForEnterPressed(); // Close MBeanServer connection // echo("\nClose the connection to the server"); jmxc.close(); echo("\nBye! Bye!"); } private static void echo(String msg) { System.out.println(msg); } private static void sleep(int millis) { try { Thread.sleep(millis); } catch (InterruptedException e) { e.printStackTrace(); } } private static void waitForEnterPressed() { try { echo("\nPress <Enter> to continue..."); System.in.read(); } catch (IOException e) { e.printStackTrace(); } } }