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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.Collections;
28  import java.util.Iterator;
29  import java.util.List;
30  import java.util.Vector;
31  
32  import org.slf4j.Marker;
33  
34  /**
35   * A simple implementation of the {@link Marker} interface.
36   * 
37   * @author Ceki Gülcü
38   * @author Joern Huxhorn
39   */
40  public class BasicMarker implements Marker {
41  
42      private static final long serialVersionUID = 1803952589649545191L;
43  
44      private final String name;
45      private List<Marker> referenceList;
46  
47      BasicMarker(String name) {
48          if (name == null) {
49              throw new IllegalArgumentException("A marker name cannot be null");
50          }
51          this.name = name;
52      }
53  
54      public String getName() {
55          return name;
56      }
57  
58      public synchronized void add(Marker reference) {
59          if (reference == null) {
60              throw new IllegalArgumentException("A null value cannot be added to a Marker as reference.");
61          }
62  
63          // no point in adding the reference multiple times
64          if (this.contains(reference)) {
65              return;
66  
67          } else if (reference.contains(this)) { // avoid recursion
68              // a potential reference should not its future "parent" as a reference
69              return;
70          } else {
71              // let's add the reference
72              if (referenceList == null) {
73                  referenceList = new Vector<Marker>();
74              }
75              referenceList.add(reference);
76          }
77  
78      }
79  
80      public synchronized boolean hasReferences() {
81          return ((referenceList != null) && (referenceList.size() > 0));
82      }
83  
84      public boolean hasChildren() {
85          return hasReferences();
86      }
87  
88      public synchronized Iterator<Marker> iterator() {
89          if (referenceList != null) {
90              return referenceList.iterator();
91          } else {
92              List<Marker> emptyList = Collections.emptyList();
93              return emptyList.iterator();
94          }
95      }
96  
97      public synchronized boolean remove(Marker referenceToRemove) {
98          if (referenceList == null) {
99              return false;
100         }
101 
102         int size = referenceList.size();
103         for (int i = 0; i < size; i++) {
104             Marker m = (Marker) referenceList.get(i);
105             if (referenceToRemove.equals(m)) {
106                 referenceList.remove(i);
107                 return true;
108             }
109         }
110         return false;
111     }
112 
113     public boolean contains(Marker other) {
114         if (other == null) {
115             throw new IllegalArgumentException("Other cannot be null");
116         }
117 
118         if (this.equals(other)) {
119             return true;
120         }
121 
122         if (hasReferences()) {
123             for (int i = 0; i < referenceList.size(); i++) {
124                 Marker ref = (Marker) referenceList.get(i);
125                 if (ref.contains(other)) {
126                     return true;
127                 }
128             }
129         }
130         return false;
131     }
132 
133     /**
134      * This method is mainly used with Expression Evaluators.
135      */
136     public boolean contains(String name) {
137         if (name == null) {
138             throw new IllegalArgumentException("Other cannot be null");
139         }
140 
141         if (this.name.equals(name)) {
142             return true;
143         }
144 
145         if (hasReferences()) {
146             for (int i = 0; i < referenceList.size(); i++) {
147                 Marker ref = (Marker) referenceList.get(i);
148                 if (ref.contains(name)) {
149                     return true;
150                 }
151             }
152         }
153         return false;
154     }
155 
156     private static String OPEN = "[ ";
157     private static String CLOSE = " ]";
158     private static String SEP = ", ";
159 
160     public boolean equals(Object obj) {
161         if (this == obj)
162             return true;
163         if (obj == null)
164             return false;
165         if (!(obj instanceof Marker))
166             return false;
167 
168         final Marker other = (Marker) obj;
169         return name.equals(other.getName());
170     }
171 
172     public int hashCode() {
173         return name.hashCode();
174     }
175 
176     public String toString() {
177         if (!this.hasReferences()) {
178             return this.getName();
179         }
180         Iterator<Marker> it = this.iterator();
181         Marker reference;
182         StringBuilder sb = new StringBuilder(this.getName());
183         sb.append(' ').append(OPEN);
184         while (it.hasNext()) {
185             reference = (Marker) it.next();
186             sb.append(reference.getName());
187             if (it.hasNext()) {
188                 sb.append(SEP);
189             }
190         }
191         sb.append(CLOSE);
192 
193         return sb.toString();
194     }
195 }