SystemInfoImpl.java

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package org.glassfish.admin.amx.impl.mbean;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.management.MBeanServer;
import org.glassfish.admin.amx.base.SystemInfo;
import org.glassfish.external.amx.AMXGlassfish;

/**
Loaded as MBean "amx:j2eeType=X-SystemInfo,name=na"
 */
public final class SystemInfoImpl extends AMXImplBase //implements SystemInfo
{
    private final ConcurrentMap<String, Boolean> mFeatures;

    public SystemInfoImpl(
            final MBeanServer server) {

        super(AMXGlassfish.DEFAULT.domainRoot(), SystemInfo.class);

        // must be thread-safe, because features can be added at a later time
        mFeatures = new ConcurrentHashMap<String, Boolean>();
    }

    /**
    Advertise the presence of a feature.  For consistency, feature names should normally be
    of the form <description>_FEATURE.  For example: "HELLO-WORLD_FEATURE".
    <p>
    To change a feature�s availability to unavailable, pass 'false' for 'available' (there is no
    removeFeature() call).  This is discouraged unless dynamic presence/absence is an inherent
    characteristic of the feature; clients might check only once for presence or absence.

    @param featureName name of the feature
    @param available  should be 'true' unless an explicit 'false' (unavailable) is desired
     */
    public void addFeature(final String featureName, final boolean available) {
        if (featureName == null || featureName.length() == 0) {
            throw new IllegalArgumentException();
        }

        mFeatures.put(featureName, Boolean.valueOf(available));
    }

    public String[] getFeatureNames() {
        // make a copy so that we can reliably call List.size()
        // According to Brian Goetz, this approach is thread safe for using the keySet.
        final List<String> nameList = new ArrayList<String>(mFeatures.keySet());

        final String[] names = new String[nameList.size()];
        nameList.toArray(names);
        return names;
    }

    public boolean supportsFeature(final String key) {
        boolean supports = false;

        Boolean result = mFeatures.get(key);
        if (result == null) {
            result = Boolean.FALSE;
        }

        return (result);
    }

    /**
    Return a Map keyed by an arbitrary String denoting some feature.  The value
    is the time in milliseconds.  Code should not rely on the keys as they are subject to
    changes, additions, or removal at any time, except as otherwise documented.
    Even documented items should be used only for informational purposes,
    such as assessing performance.
     */
    public Map<String, Long> getPerformanceMillis() {
        return new HashMap<String, Long>();
    }
}