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 */
017 package org.apache.logging.log4j;
018
019 import java.io.Serializable;
020 import java.util.Collection;
021 import java.util.Locale;
022 import java.util.concurrent.ConcurrentHashMap;
023 import java.util.concurrent.ConcurrentMap;
024
025 import org.apache.logging.log4j.spi.StandardLevel;
026
027 /**
028 * Levels used for identifying the severity of an event. Levels are organized from most specific to least:
029 * <ul>
030 * <li>{@link #OFF} (most specific, no logging)</li>
031 * <li>{@link #FATAL} (most specific, little data)</li>
032 * <li>{@link #ERROR}</li>
033 * <li>{@link #WARN}</li>
034 * <li>{@link #INFO}</li>
035 * <li>{@link #DEBUG}</li>
036 * <li>{@link #TRACE} (least specific, a lot of data)</li>
037 * <li>{@link #ALL} (least specific, all data)</li>
038 * </ul>
039 *
040 * Typically, configuring a level in a filter or on a logger will cause logging events of that level and those
041 * that are more specific to pass through the filter.
042 * A special level, {@link #ALL}, is guaranteed to capture all levels when used in logging configurations.
043 */
044 public final class Level implements Comparable<Level>, Serializable {
045
046 private static final long serialVersionUID = 1581082L;
047 private static final ConcurrentMap<String, Level> levels = new ConcurrentHashMap<String, Level>();
048
049 /**
050 * No events will be logged.
051 */
052 public static final Level OFF;
053
054 /**
055 * A severe error that will prevent the application from continuing.
056 */
057 public static final Level FATAL;
058
059 /**
060 * An error in the application, possibly recoverable.
061 */
062 public static final Level ERROR;
063
064 /**
065 * An event that might possible lead to an error.
066 */
067 public static final Level WARN;
068
069 /**
070 * An event for informational purposes.
071 */
072 public static final Level INFO;
073
074 /**
075 * A general debugging event.
076 */
077 public static final Level DEBUG;
078
079 /**
080 * A fine-grained debug message, typically capturing the flow through the application.
081 */
082 public static final Level TRACE;
083
084 /**
085 * All events should be logged.
086 */
087 public static final Level ALL;
088
089 static {
090 OFF = new Level("OFF", StandardLevel.OFF.intLevel());
091 FATAL = new Level("FATAL", StandardLevel.FATAL.intLevel());
092 ERROR = new Level("ERROR", StandardLevel.ERROR.intLevel());
093 WARN = new Level("WARN", StandardLevel.WARN.intLevel());
094 INFO = new Level("INFO", StandardLevel.INFO.intLevel());
095 DEBUG = new Level("DEBUG", StandardLevel.DEBUG.intLevel());
096 TRACE = new Level("TRACE", StandardLevel.TRACE.intLevel());
097 ALL = new Level("ALL", StandardLevel.ALL.intLevel());
098 }
099
100 /**
101 * @since 2.1
102 */
103 public static final String CATEGORY = "Level";
104
105 private final String name;
106 private final int intLevel;
107 private final StandardLevel standardLevel;
108
109 private Level(final String name, final int intLevel) {
110 if (name == null || name.isEmpty()) {
111 throw new IllegalArgumentException("Illegal null Level constant");
112 }
113 if (intLevel < 0) {
114 throw new IllegalArgumentException("Illegal Level int less than zero.");
115 }
116 this.name = name;
117 this.intLevel = intLevel;
118 this.standardLevel = StandardLevel.getStandardLevel(intLevel);
119 if (levels.putIfAbsent(name, this) != null) {
120 throw new IllegalStateException("Level " + name + " has already been defined.");
121 }
122 }
123
124 /**
125 * Gets the integral value of this Level.
126 *
127 * @return the value of this Level.
128 */
129 public int intLevel() {
130 return this.intLevel;
131 }
132
133 /**
134 * Gets the standard Level values as an enum.
135 *
136 * @return an enum of the standard Levels.
137 */
138 public StandardLevel getStandardLevel() {
139 return standardLevel;
140 }
141
142 /**
143 * Compares this level against the level passed as an argument and returns true if this level is the same or is less
144 * specific.T
145 *
146 * @param level
147 * The level to test.
148 * @return True if this level Level is less specific or the same as the given Level.
149 */
150 public boolean isLessSpecificThan(final Level level) {
151 return this.intLevel >= level.intLevel;
152 }
153
154 /**
155 * Compares this level against the level passed as an argument and returns true if this level is the same or is more
156 * specific.
157 *
158 * @param level
159 * The level to test.
160 * @return True if this level Level is more specific or the same as the given Level.
161 */
162 public boolean isMoreSpecificThan(final Level level) {
163 return this.intLevel <= level.intLevel;
164 }
165
166 @Override
167 @SuppressWarnings("CloneDoesntCallSuperClone")
168 public Level clone() throws CloneNotSupportedException {
169 throw new CloneNotSupportedException();
170 }
171
172 @Override
173 public int compareTo(final Level other) {
174 return intLevel < other.intLevel ? -1 : (intLevel > other.intLevel ? 1 : 0);
175 }
176
177 @Override
178 public boolean equals(final Object other) {
179 return other instanceof Level && other == this;
180 }
181
182 public Class<Level> getDeclaringClass() {
183 return Level.class;
184 }
185
186 @Override
187 public int hashCode() {
188 return this.name.hashCode();
189 }
190
191 /**
192 * Gets the symbolic name of this Level. Equivalent to calling {@link #toString()}.
193 *
194 * @return the name of this Level.
195 */
196 public String name() {
197 return this.name;
198 }
199
200 @Override
201 public String toString() {
202 return this.name;
203 }
204
205 /**
206 * Retrieves an existing Level or creates on if it didn't previously exist.
207 * @param name The name of the level.
208 * @param intValue The integer value for the Level. If the level was previously created this value is ignored.
209 * @return The Level.
210 * @throws java.lang.IllegalArgumentException if the name is null or intValue is less than zero.
211 */
212 public static Level forName(final String name, final int intValue) {
213 final Level level = levels.get(name);
214 if (level != null) {
215 return level;
216 }
217 try {
218 return new Level(name, intValue);
219 } catch (final IllegalStateException ex) {
220 // The level was added by something else so just return that one.
221 return levels.get(name);
222 }
223 }
224
225 /**
226 * Return the Level associated with the name or null if the Level cannot be found.
227 * @param name The name of the Level.
228 * @return The Level or null.
229 */
230 public static Level getLevel(final String name) {
231 return levels.get(name);
232 }
233
234 /**
235 * Converts the string passed as argument to a level. If the
236 * conversion fails, then this method returns {@link #DEBUG}.
237 *
238 * @param sArg The name of the desired Level.
239 * @return The Level associated with the String.
240 */
241 public static Level toLevel(final String sArg) {
242 return toLevel(sArg, Level.DEBUG);
243 }
244
245 /**
246 * Converts the string passed as argument to a level. If the
247 * conversion fails, then this method returns the value of
248 * <code>defaultLevel</code>.
249 *
250 * @param name The name of the desired Level.
251 * @param defaultLevel The Level to use if the String is invalid.
252 * @return The Level associated with the String.
253 */
254 public static Level toLevel(final String name, final Level defaultLevel) {
255 if (name == null) {
256 return defaultLevel;
257 }
258 final Level level = levels.get(name.toUpperCase(Locale.ENGLISH));
259 return level == null ? defaultLevel : level;
260 }
261
262 /**
263 * Return an array of all the Levels that have been registered.
264 * @return An array of Levels.
265 */
266 public static Level[] values() {
267 final Collection<Level> values = Level.levels.values();
268 return values.toArray(new Level[values.size()]);
269 }
270
271 /**
272 * Return the Level associated with the name.
273 * @param name The name of the Level to return.
274 * @return The Level.
275 * @throws java.lang.NullPointerException if the Level name is {@code null}.
276 * @throws java.lang.IllegalArgumentException if the Level name is not registered.
277 */
278 public static Level valueOf(final String name) {
279 if (name == null) {
280 throw new NullPointerException("No level name given.");
281 }
282 final String levelName = name.toUpperCase(Locale.ENGLISH);
283 if (levels.containsKey(levelName)) {
284 return levels.get(levelName);
285 }
286 throw new IllegalArgumentException("Unknown level constant [" + levelName + "].");
287 }
288
289 /**
290 * Returns the enum constant of the specified enum type with the specified name. The name must match exactly an
291 * identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
292 *
293 * @param enumType the {@code Class} object of the enum type from which to return a constant
294 * @param name the name of the constant to return
295 * @param <T> The enum type whose constant is to be returned
296 * @return the enum constant of the specified enum type with the specified name
297 * @throws java.lang.IllegalArgumentException if the specified enum type has no constant with the specified name,
298 * or the specified class object does not represent an enum type
299 * @throws java.lang.NullPointerException if {@code enumType} or {@code name} are {@code null}
300 * @see java.lang.Enum#valueOf(Class, String)
301 */
302 public static <T extends Enum<T>> T valueOf(final Class<T> enumType, final String name) {
303 return Enum.valueOf(enumType, name);
304 }
305
306 // for deserialization
307 protected Object readResolve() {
308 return Level.valueOf(this.name);
309 }
310 }
311