JVMGCStatsProvider.java

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package org.glassfish.admin.monitor.jvm;

import java.lang.management.GarbageCollectorMXBean;
import java.lang.management.ManagementFactory;
import java.util.List;
import org.glassfish.external.statistics.CountStatistic;
import org.glassfish.external.statistics.impl.CountStatisticImpl;
import org.glassfish.gmbal.Description;
import org.glassfish.gmbal.AMXMetadata;
import org.glassfish.gmbal.ManagedAttribute;
import org.glassfish.gmbal.ManagedObject;

/* jvm.garbage-collectors */
// v2 mbean: com.sun.appserv:name=Copy,type=garbage-collector,category=monitor,server=server
// v3 mbean:
@AMXMetadata(type="garbage-collector-mon", group="monitoring")
@ManagedObject
@Description( "JVM Garbage Collectors Statistics" )
public class JVMGCStatsProvider {

    private List<GarbageCollectorMXBean> gcBeanList = ManagementFactory.getGarbageCollectorMXBeans();
    private String gcName = null;

    private CountStatisticImpl collectionCount = new CountStatisticImpl(
            "CollectionCount", CountStatisticImpl.UNIT_COUNT,
                "Total number of collections that have occurred" );

    private CountStatisticImpl collectionTimeCount = new CountStatisticImpl(
            "CollectionTime", CountStatisticImpl.UNIT_MILLISECOND,
                "Approximate accumulated collection elapsed time in milliseconds" );

    public JVMGCStatsProvider(String gcName) {
        this.gcName = gcName;
    }

    @ManagedAttribute(id="collectioncount-count")
    @Description( "total number of collections that have occurred" )
    public CountStatistic getCollectionCount() {
        long counts = -1;
        for (GarbageCollectorMXBean gcBean : gcBeanList) {
            if (gcBean.getName().equals(gcName)) {
                counts = gcBean.getCollectionCount();
            }
        }
        collectionCount.setCount(counts);
        return collectionCount;
    }

    @ManagedAttribute(id="collectiontime-count")
    @Description( "approximate accumulated collection elapsed time in milliseconds" )
    public CountStatistic getCollectionTime() {
        long times = -1;
        int i = 0;
        for (GarbageCollectorMXBean gcBean : gcBeanList) {
            if (gcBean.getName().equals(gcName)) {
                times = gcBean.getCollectionTime();
            }
        }
        collectionTimeCount.setCount(times);
        return collectionTimeCount;
    }

}