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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache license, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License. You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the license for the specific language governing permissions and
15   * limitations under the license.
16   */
17  package org.apache.log4j;
18  
19  import java.io.IOException;
20  import java.io.ObjectInputStream;
21  import java.io.ObjectOutputStream;
22  import java.io.ObjectStreamException;
23  import java.io.Serializable;
24  import java.util.Locale;
25  
26  import org.apache.logging.log4j.util.Strings;
27  
28  /**
29   * Defines the minimum set of levels recognized by the system, that is
30   * <code>OFF</code>, <code>FATAL</code>, <code>ERROR</code>,
31   * <code>WARN</code>, <code>INFO</code>, <code>DEBUG</code>
32   * and <code>ALL</code>.
33   * <p>
34   * The <code>Level</code> class may be subclassed to define a larger
35   * level set.
36   * </p>
37   */
38  public class Level extends Priority implements Serializable {
39  
40      /**
41       * TRACE level integer value.
42       *
43       * @since 1.2.12
44       */
45      public static final int TRACE_INT = 5000;
46  
47      /**
48       * The <code>OFF</code> has the highest possible rank and is
49       * intended to turn off logging.
50       */
51      public static final Level OFF = new Level(OFF_INT, "OFF", 0);
52  
53      /**
54       * The <code>FATAL</code> level designates very severe error
55       * events that will presumably lead the application to abort.
56       */
57      public static final Level FATAL = new Level(FATAL_INT, "FATAL", 0);
58  
59      /**
60       * The <code>ERROR</code> level designates error events that
61       * might still allow the application to continue running.
62       */
63      public static final Level ERROR = new Level(ERROR_INT, "ERROR", 3);
64  
65      /**
66       * The <code>WARN</code> level designates potentially harmful situations.
67       */
68      public static final Level WARN = new Level(WARN_INT, "WARN", 4);
69  
70      /**
71       * The <code>INFO</code> level designates informational messages
72       * that highlight the progress of the application at coarse-grained
73       * level.
74       */
75      public static final Level INFO = new Level(INFO_INT, "INFO", 6);
76  
77      /**
78       * The <code>DEBUG</code> Level designates fine-grained
79       * informational events that are most useful to debug an
80       * application.
81       */
82      public static final Level DEBUG = new Level(DEBUG_INT, "DEBUG", 7);
83  
84      /**
85       * The <code>TRACE</code> Level designates finer-grained
86       * informational events than the <code>DEBUG</code> level.
87       */
88      public static final Level TRACE = new Level(TRACE_INT, "TRACE", 7);
89  
90      /**
91       * The <code>ALL</code> has the lowest possible rank and is intended to
92       * turn on all logging.
93       */
94      public static final Level ALL = new Level(ALL_INT, "ALL", 7);
95  
96      /**
97       * Serialization version id.
98       */
99      private static final long serialVersionUID = 3491141966387921974L;
100 
101     /**
102      * Instantiate a Level object.
103      *
104      * @param level            The logging level.
105      * @param levelStr         The level name.
106      * @param syslogEquivalent The matching syslog level.
107      */
108     protected Level(final int level, final String levelStr, final int syslogEquivalent) {
109         super(level, levelStr, syslogEquivalent);
110     }
111 
112 
113     /**
114      * Convert the string passed as argument to a level. If the
115      * conversion fails, then this method returns {@link #DEBUG}.
116      *
117      * @param sArg The level name.
118      * @return The Level.
119      */
120     public static Level toLevel(final String sArg) {
121         return toLevel(sArg, Level.DEBUG);
122     }
123 
124     /**
125      * Convert an integer passed as argument to a level. If the
126      * conversion fails, then this method returns {@link #DEBUG}.
127      *
128      * @param val The integer value of the Level.
129      * @return The Level.
130      */
131     public static Level toLevel(final int val) {
132         return toLevel(val, Level.DEBUG);
133     }
134 
135     /**
136      * Convert an integer passed as argument to a level. If the
137      * conversion fails, then this method returns the specified default.
138      *
139      * @param val          The integer value of the Level.
140      * @param defaultLevel the default level if the integer doesn't match.
141      * @return The matching Level.
142      */
143     public static Level toLevel(final int val, final Level defaultLevel) {
144         switch (val) {
145             case ALL_INT:
146                 return ALL;
147             case DEBUG_INT:
148                 return Level.DEBUG;
149             case INFO_INT:
150                 return Level.INFO;
151             case WARN_INT:
152                 return Level.WARN;
153             case ERROR_INT:
154                 return Level.ERROR;
155             case FATAL_INT:
156                 return Level.FATAL;
157             case OFF_INT:
158                 return OFF;
159             case TRACE_INT:
160                 return Level.TRACE;
161             default:
162                 return defaultLevel;
163         }
164     }
165 
166     /**
167      * Convert the string passed as argument to a level. If the
168      * conversion fails, then this method returns the value of
169      * <code>defaultLevel</code>.
170      * @param sArg The name of the Level.
171      * @param defaultLevel The default Level to use.
172      * @return the matching Level.
173      */
174     public static Level toLevel(final String sArg, final Level defaultLevel) {
175         if (sArg == null) {
176             return defaultLevel;
177         }
178         final String s = sArg.toUpperCase(Locale.ROOT);
179         switch (s) {
180         case "ALL":
181             return Level.ALL;
182         case "DEBUG":
183             return Level.DEBUG;
184         case "INFO":
185             return Level.INFO;
186         case "WARN":
187             return Level.WARN;
188         case "ERROR":
189             return Level.ERROR;
190         case "FATAL":
191             return Level.FATAL;
192         case "OFF":
193             return Level.OFF;
194         case "TRACE":
195             return Level.TRACE;
196         default:
197             return defaultLevel;
198         }
199     }
200 
201     /**
202      * Custom deserialization of Level.
203      *
204      * @param s serialization stream.
205      * @throws IOException            if IO exception.
206      * @throws ClassNotFoundException if class not found.
207      */
208     private void readObject(final ObjectInputStream s) throws IOException, ClassNotFoundException {
209         s.defaultReadObject();
210         level = s.readInt();
211         syslogEquivalent = s.readInt();
212         levelStr = s.readUTF();
213         if (levelStr == null) {
214             levelStr = Strings.EMPTY;
215         }
216     }
217 
218     /**
219      * Serialize level.
220      *
221      * @param s serialization stream.
222      * @throws IOException if exception during serialization.
223      */
224     private void writeObject(final ObjectOutputStream s) throws IOException {
225         s.defaultWriteObject();
226         s.writeInt(level);
227         s.writeInt(syslogEquivalent);
228         s.writeUTF(levelStr);
229     }
230 
231     /**
232      * Resolved deserialized level to one of the stock instances.
233      * May be overridden in classes derived from Level.
234      *
235      * @return resolved object.
236      * @throws ObjectStreamException if exception during resolution.
237      */
238     protected Object readResolve() throws ObjectStreamException {
239         //
240         //  if the deserialized object is exactly an instance of Level
241         //
242         if (getClass() == Level.class) {
243             return toLevel(level);
244         }
245         //
246         //   extension of Level can't substitute stock item
247         //
248         return this;
249     }
250 
251 }
252