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      */
BasicMarkerFactory()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      */
getMarker(String name)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      */
exists(String name)81     public boolean exists(String name) {
82         if (name == null) {
83             return false;
84         }
85         return markerMap.containsKey(name);
86     }
87 
detachMarker(String name)88     public boolean detachMarker(String name) {
89         if (name == null) {
90             return false;
91         }
92         return (markerMap.remove(name) != null);
93     }
94 
getDetachedMarker(String name)95     public Marker getDetachedMarker(String name) {
96         return new BasicMarker(name);
97     }
98 
99 }
100