/* * @(#)PrintGCStat.java	1.4 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. *//* * @(#)PrintGCStat.java	1.4 05/11/17 */import static java.lang.management.ManagementFactory.*;import java.lang.management.*;import javax.management.*;import java.io.*;import java.util.*;/** * Example of using the java.lang.management API to monitor  * the memory usage and garbage collection statistics. * * @author  Mandy Chung * @version %% 11/17/05 */public class PrintGCStat {    private RuntimeMXBean rmbean;    private MemoryMXBean mmbean;    private List<MemoryPoolMXBean> pools;    private List<GarbageCollectorMXBean> gcmbeans;        /**     * Constructs a PrintGCStat object to monitor a remote JVM.     */    public PrintGCStat(MBeanServerConnection server) throws IOException {        // Create the platform mxbean proxies        this.rmbean = newPlatformMXBeanProxy(server,                                             RUNTIME_MXBEAN_NAME,                                             RuntimeMXBean.class);        this.mmbean = newPlatformMXBeanProxy(server,                                             MEMORY_MXBEAN_NAME,                                             MemoryMXBean.class);        ObjectName poolName = null;        ObjectName gcName = null;        try {            poolName = new ObjectName(MEMORY_POOL_MXBEAN_DOMAIN_TYPE+",*");            gcName = new ObjectName(GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE+",*");        } catch (MalformedObjectNameException e) {            // should not reach here            assert(false);        }        Set mbeans = server.queryNames(poolName, null);        if (mbeans != null) {            pools = new ArrayList<MemoryPoolMXBean>();            Iterator iterator = mbeans.iterator();            while (iterator.hasNext()) {                ObjectName objName = (ObjectName) iterator.next();                MemoryPoolMXBean p =                     newPlatformMXBeanProxy(server,                                           objName.getCanonicalName(),                                           MemoryPoolMXBean.class);                pools.add(p);            }        }        mbeans = server.queryNames(gcName, null);        if (mbeans != null) {            gcmbeans = new ArrayList<GarbageCollectorMXBean>();            Iterator iterator = mbeans.iterator();            while (iterator.hasNext()) {                ObjectName objName = (ObjectName) iterator.next();                GarbageCollectorMXBean gc =                     newPlatformMXBeanProxy(server,                                           objName.getCanonicalName(),                                           GarbageCollectorMXBean.class);                gcmbeans.add(gc);            }        }    }    /**     * Constructs a PrintGCStat object to monitor the local JVM.     */    public PrintGCStat() {        // Obtain the platform mxbean instances for the running JVM.        this.rmbean = getRuntimeMXBean();        this.mmbean = getMemoryMXBean();        this.pools = getMemoryPoolMXBeans();        this.gcmbeans = getGarbageCollectorMXBeans();    }    /**     * Prints the verbose GC log to System.out to list the memory usage     * of all memory pools as well as the GC statistics.      */    public void printVerboseGc() {        System.out.print("Uptime: " + formatMillis(rmbean.getUptime()));        for (GarbageCollectorMXBean gc : gcmbeans) {            System.out.print(" [" + gc.getName() + ": ");            System.out.print("Count=" + gc.getCollectionCount());            System.out.print(" GCTime=" + formatMillis(gc.getCollectionTime()));            System.out.print("]");        }        System.out.println();        for (MemoryPoolMXBean p : pools) {            System.out.print("  [" + p.getName() + ":");            MemoryUsage u = p.getUsage();            System.out.print(" Used=" + formatBytes(u.getUsed()));            System.out.print(" Committed=" + formatBytes(u.getCommitted()));            System.out.println("]");        }    }    private String formatMillis(long ms) {        return String.format("%.4fsec", ms / (double) 1000);    }    private String formatBytes(long bytes) {        long kb = bytes;        if (bytes > 0) {            kb = bytes / 1024;        }        return kb + "K";     }}