Copyright (c) 2004-2011 QOS.ch
All rights reserved.
Permission is hereby granted, free  of charge, to any person obtaining
a  copy  of this  software  and  associated  documentation files  (the
"Software"), to  deal in  the Software without  restriction, including
without limitation  the rights to  use, copy, modify,  merge, publish,
distribute,  sublicense, and/or sell  copies of  the Software,  and to
permit persons to whom the Software  is furnished to do so, subject to
the following conditions:
The  above  copyright  notice  and  this permission  notice  shall  be
included in all copies or substantial portions of the Software.
THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
/**
 * Copyright (c) 2004-2011 QOS.ch
 * All rights reserved.
 *
 * Permission is hereby granted, free  of charge, to any person obtaining
 * a  copy  of this  software  and  associated  documentation files  (the
 * "Software"), to  deal in  the Software without  restriction, including
 * without limitation  the rights to  use, copy, modify,  merge, publish,
 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
 * permit persons to whom the Software  is furnished to do so, subject to
 * the following conditions:
 *
 * The  above  copyright  notice  and  this permission  notice  shall  be
 * included in all copies or substantial portions of the Software.
 *
 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */
package org.slf4j.helpers;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.slf4j.IMarkerFactory;
import org.slf4j.Marker;

An almost trivial implementation of the IMarkerFactory interface which creates BasicMarker instances. 
Simple logging systems can conform to the SLF4J API by binding MarkerFactory with an instance of this class. 
Author:
Ceki Gülcü/**
 * An almost trivial implementation of the {@link IMarkerFactory}
 * interface which creates {@link BasicMarker} instances.
 * 
 * <p>Simple logging systems can conform to the SLF4J API by binding
 * {@link org.slf4j.MarkerFactory} with an instance of this class.
 *
 * @author Ceki G&uuml;lc&uuml;
 */
public class BasicMarkerFactory implements IMarkerFactory {

    private final ConcurrentMap<String, Marker> markerMap = new ConcurrentHashMap<String, Marker>();

    
Regular users should not create
BasicMarkerFactory instances. Marker instances can be obtained using the static MarkerFactory.getMarker method. /**
     * Regular users should <em>not</em> create
     * <code>BasicMarkerFactory</code> instances. <code>Marker</code>
     * instances can be obtained using the static {@link
     * org.slf4j.MarkerFactory#getMarker} method.
     */
    public BasicMarkerFactory() {
    }

    
Manufacture a BasicMarker instance by name. If the instance has been created earlier, return the previously created instance. 
Params:
name – the name of the marker to be created
Returns:
a Marker instance/**
     * Manufacture a {@link BasicMarker} instance by name. If the instance has been 
     * created earlier, return the previously created instance. 
     * 
     * @param name the name of the marker to be created
     * @return a Marker instance
     */
    public Marker getMarker(String name) {
        if (name == null) {
            throw new IllegalArgumentException("Marker name cannot be null");
        }

        Marker marker = markerMap.get(name);
        if (marker == null) {
            marker = new BasicMarker(name);
            Marker oldMarker = markerMap.putIfAbsent(name, marker);
            if (oldMarker != null) {
                marker = oldMarker;
            }
        }
        return marker;
    }

    
Does the name marked already exist?
/**
     * Does the name marked already exist?
     */
    public boolean exists(String name) {
        if (name == null) {
            return false;
        }
        return markerMap.containsKey(name);
    }

    public boolean detachMarker(String name) {
        if (name == null) {
            return false;
        }
        return (markerMap.remove(name) != null);
    }

    public Marker getDetachedMarker(String name) {
        return new BasicMarker(name);
    }

}