View Javadoc

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    
96    public Marker getDetachedMarker(String name) {
97      return  new BasicMarker(name);
98    }
99    
100   
101   
102 }