001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.log4j;
018
019import java.io.IOException;
020import java.io.ObjectInputStream;
021import java.io.ObjectOutputStream;
022import java.io.ObjectStreamException;
023import java.io.Serializable;
024import java.util.Locale;
025
026import org.apache.logging.log4j.util.Strings;
027
028/**
029 * Defines the minimum set of levels recognized by the system, that is
030 * <code>OFF</code>, <code>FATAL</code>, <code>ERROR</code>,
031 * <code>WARN</code>, <code>INFO</code>, <code>DEBUG</code>
032 * and <code>ALL</code>.
033 * <p>
034 * The <code>Level</code> class may be subclassed to define a larger
035 * level set.
036 * </p>
037 */
038public class Level extends Priority implements Serializable {
039
040    /**
041     * TRACE level integer value.
042     *
043     * @since 1.2.12
044     */
045    public static final int TRACE_INT = 5000;
046
047    /**
048     * The <code>OFF</code> has the highest possible rank and is
049     * intended to turn off logging.
050     */
051    public static final Level OFF = new Level(OFF_INT, "OFF", 0);
052
053    /**
054     * The <code>FATAL</code> level designates very severe error
055     * events that will presumably lead the application to abort.
056     */
057    public static final Level FATAL = new Level(FATAL_INT, "FATAL", 0);
058
059    /**
060     * The <code>ERROR</code> level designates error events that
061     * might still allow the application to continue running.
062     */
063    public static final Level ERROR = new Level(ERROR_INT, "ERROR", 3);
064
065    /**
066     * The <code>WARN</code> level designates potentially harmful situations.
067     */
068    public static final Level WARN = new Level(WARN_INT, "WARN", 4);
069
070    /**
071     * The <code>INFO</code> level designates informational messages
072     * that highlight the progress of the application at coarse-grained
073     * level.
074     */
075    public static final Level INFO = new Level(INFO_INT, "INFO", 6);
076
077    /**
078     * The <code>DEBUG</code> Level designates fine-grained
079     * informational events that are most useful to debug an
080     * application.
081     */
082    public static final Level DEBUG = new Level(DEBUG_INT, "DEBUG", 7);
083
084    /**
085     * The <code>TRACE</code> Level designates finer-grained
086     * informational events than the <code>DEBUG</code> level.
087     */
088    public static final Level TRACE = new Level(TRACE_INT, "TRACE", 7);
089
090    /**
091     * The <code>ALL</code> has the lowest possible rank and is intended to
092     * turn on all logging.
093     */
094    public static final Level ALL = new Level(ALL_INT, "ALL", 7);
095
096    /**
097     * Serialization version id.
098     */
099    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