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 java.io.Serializable;
28 import java.util.Iterator;
29
30 /**
31 * Markers are named objects used to enrich log statements. Conforming logging
32 * system Implementations of SLF4J determine how information conveyed by markers
33 * are used, if at all. In particular, many conforming logging systems ignore
34 * marker data.
35 *
36 * <p>
37 * Markers can contain references to other markers, which in turn may contain
38 * references of their own.
39 *
40 * @author Ceki Gülcü
41 */
42 public interface Marker extends Serializable {
43
44 /**
45 * This constant represents any marker, including a null marker.
46 */
47 public final String ANY_MARKER = "*";
48
49 /**
50 * This constant represents any non-null marker.
51 */
52 public final String ANY_NON_NULL_MARKER = "+";
53
54 /**
55 * Get the name of this Marker.
56 *
57 * @return name of marker
58 */
59 public String getName();
60
61 /**
62 * Add a reference to another Marker.
63 *
64 * @param reference
65 * a reference to another marker
66 * @throws IllegalArgumentException
67 * if 'reference' is null
68 */
69 public void add(Marker reference);
70
71 /**
72 * Remove a marker reference.
73 *
74 * @param reference
75 * the marker reference to remove
76 * @return true if reference could be found and removed, false otherwise.
77 */
78 public boolean remove(Marker reference);
79
80 /**
81 * @deprecated Replaced by {@link #hasReferences()}.
82 */
83 @Deprecated
84 public boolean hasChildren();
85
86 /**
87 * Does this marker have any references?
88 *
89 * @return true if this marker has one or more references, false otherwise.
90 */
91 public boolean hasReferences();
92
93 /**
94 * Returns an Iterator which can be used to iterate over the references of this
95 * marker. An empty iterator is returned when this marker has no references.
96 *
97 * @return Iterator over the references of this marker
98 */
99 public Iterator<Marker> iterator();
100
101 /**
102 * Does this marker contain a reference to the 'other' marker? Marker A is defined
103 * to contain marker B, if A == B or if B is referenced by A, or if B is referenced
104 * by any one of A's references (recursively).
105 *
106 * @param other
107 * The marker to test for inclusion.
108 * @throws IllegalArgumentException
109 * if 'other' is null
110 * @return Whether this marker contains the other marker.
111 */
112 public boolean contains(Marker other);
113
114 /**
115 * Does this marker contain the marker named 'name'?
116 *
117 * If 'name' is null the returned value is always false.
118 *
119 * @param name The marker name to test for inclusion.
120 * @return Whether this marker contains the other marker.
121 */
122 public boolean contains(String name);
123
124 /**
125 * Markers are considered equal if they have the same name.
126 *
127 * @param o
128 * @return true, if this.name equals o.name
129 *
130 * @since 1.5.1
131 */
132 public boolean equals(Object o);
133
134 /**
135 * Compute the hash code based on the name of this marker.
136 * Note that markers are considered equal if they have the same name.
137 *
138 * @return the computed hashCode
139 * @since 1.5.1
140 */
141 public int hashCode();
142
143 }