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    1   /**
    2    * Copyright (c) 2004-2011 QOS.ch
    3    * All rights reserved.
    4    *
    5    * Permission is hereby granted, free  of charge, to any person obtaining
    6    * a  copy  of this  software  and  associated  documentation files  (the
    7    * "Software"), to  deal in  the Software without  restriction, including
    8    * without limitation  the rights to  use, copy, modify,  merge, publish,
    9    * distribute,  sublicense, and/or sell  copies of  the Software,  and to
    10   * permit persons to whom the Software  is furnished to do so, subject to
    11   * the following conditions:
    12   *
    13   * The  above  copyright  notice  and  this permission  notice  shall  be
    14   * included in all copies or substantial portions of the Software.
    15   *
    16   * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
    17   * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
    18   * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
    19   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
    20   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
    21   * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
    22   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
    23   *
    24   */
    25  package org.slf4j.helpers;
    26
    27  import java.util.concurrent.ConcurrentHashMap;
    28  import java.util.concurrent.ConcurrentMap;
    29
    30  import org.slf4j.IMarkerFactory;
    31  import org.slf4j.Marker;
    32
    33  /**
    34   * An almost trivial implementation of the {@link IMarkerFactory}
    35   * interface which creates {@link BasicMarker} instances.
    36   *
    37   * <p>Simple logging systems can conform to the SLF4J API by binding
    38   * {@link org.slf4j.MarkerFactory} with an instance of this class.
    39   *
    40   * @author Ceki G&uuml;lc&uuml;
    41   */
    42  public class BasicMarkerFactory implements IMarkerFactory {
    43
    44      private final ConcurrentMap<String, Marker> markerMap = new ConcurrentHashMap<String, Marker>();
    45
    46      /**
    47       * Regular users should <em>not</em> create
    48       * <code>BasicMarkerFactory</code> instances. <code>Marker</code>
    49       * instances can be obtained using the static {@link
    50       * org.slf4j.MarkerFactory#getMarker} method.
    51       */
    52      public BasicMarkerFactory() {
    53      }
    54
    55      /**
    56       * Manufacture a {@link BasicMarker} instance by name. If the instance has been
    57       * created earlier, return the previously created instance.
    58       *
    59       * @param name the name of the marker to be created
    60       * @return a Marker instance
    61       */
    62      public Marker getMarker(String name) {
    63          if (name == null) {
    64              throw new IllegalArgumentException("Marker name cannot be null");
    65          }
    66
    67          Marker marker = markerMap.get(name);
    68          if (marker == null) {
    69              marker = new BasicMarker(name);
    70              Marker oldMarker = markerMap.putIfAbsent(name, marker);
    71              if (oldMarker != null) {
    72                  marker = oldMarker;
    73              }
    74          }
    75          return marker;
    76      }
    77
    78      /**
    79       * Does the name marked already exist?
    80       */
    81      public boolean exists(String name) {
    82          if (name == null) {
    83              return false;
    84          }
    85          return markerMap.containsKey(name);
    86      }
    87
    88      public boolean detachMarker(String name) {
    89          if (name == null) {
    90              return false;
    91          }
    92          return (markerMap.remove(name) != null);
    93      }
    94
    95      public Marker getDetachedMarker(String name) {
    96          return new BasicMarker(name);
    97      }
    98
    99  }