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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;
26  
27  import org.slf4j.helpers.BasicMarkerFactory;
28  import org.slf4j.helpers.Util;
29  import org.slf4j.impl.StaticMarkerBinder;
30  
31  /**
32   * MarkerFactory is a utility class producing {@link Marker} instances as
33   * appropriate for the logging system currently in use.
34   * 
35   * <p>
36   * This class is essentially implemented as a wrapper around an
37   * {@link IMarkerFactory} instance bound at compile time.
38   * 
39   * <p>
40   * Please note that all methods in this class are static.
41   * 
42   * @author Ceki G&uuml;lc&uuml;
43   */
44  public class MarkerFactory {
45      static IMarkerFactory MARKER_FACTORY;
46  
47      private MarkerFactory() {
48      }
49  
50      /**
51       * As of SLF4J version 1.7.14, StaticMarkerBinder classes shipping in various bindings
52       * come with a getSingleton() method. Previously only a public field called SINGLETON 
53       * was available.
54       * 
55       * @return IMarkerFactory
56       * @throws NoClassDefFoundError in case no binding is available
57       * @since 1.7.14
58       */
59      private static IMarkerFactory bwCompatibleGetMarkerFactoryFromBinder() throws NoClassDefFoundError {
60          try {
61              return StaticMarkerBinder.getSingleton().getMarkerFactory();
62          } catch (NoSuchMethodError nsme) {
63              // binding is probably a version of SLF4J older than 1.7.14
64              return StaticMarkerBinder.SINGLETON.getMarkerFactory();
65          }
66      }
67  
68      // this is where the binding happens
69      static {
70          try {
71              MARKER_FACTORY = bwCompatibleGetMarkerFactoryFromBinder();
72          } catch (NoClassDefFoundError e) {
73              MARKER_FACTORY = new BasicMarkerFactory();
74          } catch (Exception e) {
75              // we should never get here
76              Util.report("Unexpected failure while binding MarkerFactory", e);
77          }
78      }
79  
80      /**
81       * Return a Marker instance as specified by the name parameter using the
82       * previously bound {@link IMarkerFactory}instance.
83       * 
84       * @param name
85       *          The name of the {@link Marker} object to return.
86       * @return marker
87       */
88      public static Marker getMarker(String name) {
89          return MARKER_FACTORY.getMarker(name);
90      }
91  
92      /**
93       * Create a marker which is detached (even at birth) from the MarkerFactory.
94       *
95       * @param name the name of the marker
96       * @return a dangling marker
97       * @since 1.5.1
98       */
99      public static Marker getDetachedMarker(String name) {
100         return MARKER_FACTORY.getDetachedMarker(name);
101     }
102 
103     /**
104      * Return the {@link IMarkerFactory}instance in use.
105      * 
106      * <p>The IMarkerFactory instance is usually bound with this class at 
107      * compile time.
108      * 
109      * @return the IMarkerFactory instance in use
110      */
111     public static IMarkerFactory getIMarkerFactory() {
112         return MARKER_FACTORY;
113     }
114 }