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      1 /*
      2  * Copyright 2001-2004 The Apache Software Foundation.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 // Contributors:  Kitching Simon <Simon.Kitching (at) orange.ch>
     18 //                Nicholas Wolff
     19 
     20 package org.apache.log4j;
     21 
     22 import java.io.IOException;
     23 import java.io.ObjectInputStream;
     24 import java.io.ObjectOutputStream;
     25 import java.io.ObjectStreamException;
     26 import java.io.Serializable;
     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> and
     32    <code>ALL</code>.
     33 
     34    <p>The <code>Level</code> class may be subclassed to define a larger
     35    level set.
     36 
     37    @author Ceki G&uuml;lc&uuml;
     38 
     39  */
     40 public class Level extends Priority implements Serializable {
     41 
     42     /**
     43      * TRACE level integer value.
     44      * @since 1.2.12
     45      */
     46     public static final int TRACE_INT = 5000;
     47 
     48     // match jboss' xlevel
     49     public static final int X_TRACE_INT = DEBUG_INT - 100;
     50 
     51     /**
     52        The <code>OFF</code> has the highest possible rank and is
     53        intended to turn off logging.  */
     54     final static public Level OFF = new Level(OFF_INT, "OFF", 0);
     55 
     56     /**
     57        The <code>FATAL</code> level designates very severe error
     58        events that will presumably lead the application to abort.
     59      */
     60     final static public Level FATAL = new Level(FATAL_INT, "FATAL", 0);
     61 
     62     /**
     63        The <code>ERROR</code> level designates error events that
     64        might still allow the application to continue running.  */
     65     final static public Level ERROR = new Level(ERROR_INT, "ERROR", 3);
     66 
     67     /**
     68        The <code>WARN</code> level designates potentially harmful situations.
     69     */
     70     final static public Level WARN = new Level(WARN_INT, "WARN", 4);
     71 
     72     /**
     73        The <code>INFO</code> level designates informational messages
     74        that highlight the progress of the application at coarse-grained
     75        level.  */
     76     final static public Level INFO = new Level(INFO_INT, "INFO", 6);
     77 
     78     /**
     79        The <code>DEBUG</code> Level designates fine-grained
     80        informational events that are most useful to debug an
     81        application.  */
     82     final static public 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      *  @since 1.2.12
     88       */
     89     public static final Level TRACE = new Level(TRACE_INT, "TRACE", 7);
     90 
     91     /**
     92        The <code>ALL</code> has the lowest possible rank and is intended to
     93        turn on all logging.  */
     94     final static public Level ALL = new Level(ALL_INT, "ALL", 7);
     95 
     96     /**
     97      * Serialization version id.
     98      */
     99     static final long serialVersionUID = 3491141966387921974L;
    100 
    101     /**
    102        Instantiate a Level object.
    103      */
    104     protected Level(int level, String levelStr, int syslogEquivalent) {
    105         super(level, levelStr, syslogEquivalent);
    106     }
    107 
    108     /**
    109        Convert the string passed as argument to a level. If the
    110        conversion fails, then this method returns {@link #DEBUG}.
    111     */
    112     public static Level toLevel(String sArg) {
    113         return (Level) toLevel(sArg, Level.DEBUG);
    114     }
    115 
    116     /**
    117       Convert an integer passed as argument to a level. If the
    118       conversion fails, then this method returns {@link #DEBUG}.
    119 
    120     */
    121     public static Level toLevel(int val) {
    122         return (Level) toLevel(val, Level.DEBUG);
    123     }
    124 
    125     /**
    126       Convert an integer passed as argument to a level. If the
    127       conversion fails, then this method returns the specified default.
    128     */
    129     public static Level toLevel(int val, Level defaultLevel) {
    130         switch (val) {
    131         case ALL_INT:
    132             return ALL;
    133         case DEBUG_INT:
    134             return Level.DEBUG;
    135         case INFO_INT:
    136             return Level.INFO;
    137         case WARN_INT:
    138             return Level.WARN;
    139         case ERROR_INT:
    140             return Level.ERROR;
    141         case FATAL_INT:
    142             return Level.FATAL;
    143         case OFF_INT:
    144             return OFF;
    145         case TRACE_INT:
    146             return Level.TRACE;
    147         default:
    148             return defaultLevel;
    149         }
    150     }
    151 
    152     /**
    153        Convert the string passed as argument to a level. If the
    154        conversion fails, then this method returns the value of
    155        <code>defaultLevel</code>.
    156     */
    157     public static Level toLevel(String sArg, Level defaultLevel) {
    158         if (sArg == null)
    159             return defaultLevel;
    160 
    161         String s = sArg.toUpperCase();
    162 
    163         if (s.equals("ALL"))
    164             return Level.ALL;
    165         if (s.equals("DEBUG"))
    166             return Level.DEBUG;
    167         if (s.equals("INFO"))
    168             return Level.INFO;
    169         if (s.equals("WARN"))
    170             return Level.WARN;
    171         if (s.equals("ERROR"))
    172             return Level.ERROR;
    173         if (s.equals("FATAL"))
    174             return Level.FATAL;
    175         if (s.equals("OFF"))
    176             return Level.OFF;
    177         if (s.equals("TRACE"))
    178             return Level.TRACE;
    179         return defaultLevel;
    180     }
    181 
    182     /**
    183      * Custom deserialization of Level.
    184      * @param s serialization stream.
    185      * @throws IOException if IO exception.
    186      * @throws ClassNotFoundException if class not found.
    187      */
    188     private void readObject(final ObjectInputStream s) throws IOException, ClassNotFoundException {
    189         s.defaultReadObject();
    190         level = s.readInt();
    191         syslogEquivalent = s.readInt();
    192         levelStr = s.readUTF();
    193         if (levelStr == null) {
    194             levelStr = "";
    195         }
    196     }
    197 
    198     /**
    199      * Serialize level.
    200      * @param s serialization stream.
    201      * @throws IOException if exception during serialization.
    202      */
    203     private void writeObject(final ObjectOutputStream s) throws IOException {
    204         s.defaultWriteObject();
    205         s.writeInt(level);
    206         s.writeInt(syslogEquivalent);
    207         s.writeUTF(levelStr);
    208     }
    209 
    210     /**
    211      * Resolved deserialized level to one of the stock instances.
    212      * May be overriden in classes derived from Level.
    213      * @return resolved object.
    214      * @throws ObjectStreamException if exception during resolution.
    215      */
    216     private Object readResolve() throws ObjectStreamException {
    217         //
    218         // if the deserizalized object is exactly an instance of Level
    219         //
    220         if (getClass() == Level.class) {
    221             return toLevel(level);
    222         }
    223         //
    224         // extension of Level can't substitute stock item
    225         //
    226         return this;
    227     }
    228 }