    001/**
    002 * Copyright (c) 2004-2011 QOS.ch
    003 * All rights reserved.
    004 *
    005 * Permission is hereby granted, free  of charge, to any person obtaining
    006 * a  copy  of this  software  and  associated  documentation files  (the
    007 * "Software"), to  deal in  the Software without  restriction, including
    008 * without limitation  the rights to  use, copy, modify,  merge, publish,
    009 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
    010 * permit persons to whom the Software  is furnished to do so, subject to
    011 * the following conditions:
    012 *
    013 * The  above  copyright  notice  and  this permission  notice  shall  be
    014 * included in all copies or substantial portions of the Software.
    015 *
    016 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
    017 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
    018 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
    019 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
    020 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
    021 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
    022 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
    023 *
    024 */
    025package org.slf4j.helpers;
    026
    027import java.util.concurrent.ConcurrentHashMap;
    028import java.util.concurrent.ConcurrentMap;
    029
    030import org.slf4j.IMarkerFactory;
    031import org.slf4j.Marker;
    032
    033/**
    034 * An almost trivial implementation of the {@link IMarkerFactory}
    035 * interface which creates {@link BasicMarker} instances.
    036 *
    037 * <p>Simple logging systems can conform to the SLF4J API by binding
    038 * {@link org.slf4j.MarkerFactory} with an instance of this class.
    039 *
    040 * @author Ceki G&uuml;lc&uuml;
    041 */
    042public class BasicMarkerFactory implements IMarkerFactory {
    043
    044    private final ConcurrentMap<String, Marker> markerMap = new ConcurrentHashMap<String, Marker>();
    045
    046    /**
    047     * Regular users should <em>not</em> create
    048     * <code>BasicMarkerFactory</code> instances. <code>Marker</code>
    049     * instances can be obtained using the static {@link
    050     * org.slf4j.MarkerFactory#getMarker} method.
    051     */
    052    public BasicMarkerFactory() {
    053    }
    054
    055    /**
    056     * Manufacture a {@link BasicMarker} instance by name. If the instance has been
    057     * created earlier, return the previously created instance.
    058     *
    059     * @param name the name of the marker to be created
    060     * @return a Marker instance
    061     */
    062    public Marker getMarker(String name) {
    063        if (name == null) {
    064            throw new IllegalArgumentException("Marker name cannot be null");
    065        }
    066
    067        Marker marker = markerMap.get(name);
    068        if (marker == null) {
    069            marker = new BasicMarker(name);
    070            Marker oldMarker = markerMap.putIfAbsent(name, marker);
    071            if (oldMarker != null) {
    072                marker = oldMarker;
    073            }
    074        }
    075        return marker;
    076    }
    077
    078    /**
    079     * Does the name marked already exist?
    080     */
    081    public boolean exists(String name) {
    082        if (name == null) {
    083            return false;
    084        }
    085        return markerMap.containsKey(name);
    086    }
    087
    088    public boolean detachMarker(String name) {
    089        if (name == null) {
    090            return false;
    091        }
    092        return (markerMap.remove(name) != null);
    093    }
    094
    095    public Marker getDetachedMarker(String name) {
    096        return new BasicMarker(name);
    097    }
    098
    099}