Apache Log4j provides the interface that applications should code to and provides the adapter components required for implementers to create a logging implementation.

Bytecode (Java 1.4) for Apache Log4j is provided in a JAR file like log4j-1.2.17.jar.

Source Code files for Apache Log4j are provided in both binary packge like log4j-1.2.17.zip and source package like log4j-1.2.17-sources.zip. You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j 1.2.17 below.

⏎ org/apache/log4j/helpers/UtilLoggingLevel.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.log4j.helpers;

import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Level;

/**
 * An extension of the Level class that provides support for java.util.logging
 * Levels.
 *
 *
 * @author Scott Deboy (sdeboy@apache.org)
 */

public class UtilLoggingLevel extends Level {

    /**
     * Serialization version id.
     */
    private static final long serialVersionUID = 909301162611820211L;

    /**
     * Numerical value for SEVERE.
     */
    public static final int SEVERE_INT = 22000;
    /**
     * Numerical value for WARNING.
     */
    public static final int WARNING_INT = 21000;

    //INFO level defined in parent as 20000..no need to redefine here
    
    /**
     * Numerical value for CONFIG.
     */
    public static final int CONFIG_INT = 14000;
    /**
     * Numerical value for FINE.
     */
    public static final int FINE_INT = 13000;
    /**
     * Numerical value for FINER.
     */
    public static final int FINER_INT = 12000;
    /**
     * Numerical value for FINEST.
     */
    public static final int FINEST_INT = 11000;
    /**
     * Numerical value for UNKNOWN.
     */
    public static final int UNKNOWN_INT = 10000;

    /**
     * SEVERE.
     */
    public static final UtilLoggingLevel SEVERE =
            new UtilLoggingLevel(SEVERE_INT, "SEVERE", 0);
    /**
     * WARNING.
     */
    public static final UtilLoggingLevel WARNING =
            new UtilLoggingLevel(WARNING_INT, "WARNING", 4);
    /**
     * INFO.
     */
    //note: we've aligned the int values of the java.util.logging INFO level with log4j's level
    public static final UtilLoggingLevel INFO =
            new UtilLoggingLevel(INFO_INT, "INFO", 5);
    /**
     * CONFIG.
     */
    public static final UtilLoggingLevel CONFIG =
            new UtilLoggingLevel(CONFIG_INT, "CONFIG", 6);
    /**
     * FINE.
     */
    public static final UtilLoggingLevel FINE =
            new UtilLoggingLevel(FINE_INT, "FINE", 7);
    /**
     * FINER.
     */
    public static final UtilLoggingLevel FINER =
            new UtilLoggingLevel(FINER_INT, "FINER", 8);
    /**
     * FINEST.
     */
    public static final UtilLoggingLevel FINEST =
            new UtilLoggingLevel(FINEST_INT, "FINEST", 9);

    /**
     * Create new instance.
     * @param level numeric value for level.
     * @param levelStr symbolic name for level.
     * @param syslogEquivalent Equivalent syslog severity.
     */
    protected UtilLoggingLevel(final int level,
                               final String levelStr,
                               final int syslogEquivalent) {
        super(level, levelStr, syslogEquivalent);
    }

    /**
     * Convert an integer passed as argument to a level. If the
     * conversion fails, then this method returns the specified default.
     * @param val numeric value.
     * @param defaultLevel level to be returned if no level matches
     * numeric value.
     * @return matching level or default level.
     */
    public static UtilLoggingLevel toLevel(final int val,
                               final UtilLoggingLevel defaultLevel) {
        switch (val) {
            case SEVERE_INT:
                return SEVERE;

            case WARNING_INT:
                return WARNING;

            case INFO_INT:
                return INFO;

            case CONFIG_INT:
                return CONFIG;

            case FINE_INT:
                return FINE;

            case FINER_INT:
                return FINER;

            case FINEST_INT:
                return FINEST;

            default:
                return defaultLevel;
        }
    }

    /**
     * Gets level matching numeric value.
     * @param val numeric value.
     * @return  matching level or UtilLoggerLevel.FINEST if no match.
     */
    public static Level toLevel(final int val) {
        return toLevel(val, FINEST);
    }

    /**
     * Gets list of supported levels.
     * @return  list of supported levels.
     */
    public static List getAllPossibleLevels() {
        ArrayList list = new ArrayList();
        list.add(FINE);
        list.add(FINER);
        list.add(FINEST);
        list.add(INFO);
        list.add(CONFIG);
        list.add(WARNING);
        list.add(SEVERE);
        return list;
    }

    /**
     * Get level with specified symbolic name.
     * @param s symbolic name.
     * @return matching level or Level.DEBUG if no match.
     */
    public static Level toLevel(final String s) {
        return toLevel(s, Level.DEBUG);
    }


    /**
     * Get level with specified symbolic name.
     * @param sArg symbolic name.
     * @param defaultLevel level to return if no match.
     * @return matching level or defaultLevel if no match.
     */
    public static Level toLevel(final String sArg,
                                final Level defaultLevel) {
        if (sArg == null) {
            return defaultLevel;
        }

        String s = sArg.toUpperCase();

        if (s.equals("SEVERE")) {
            return SEVERE;
        }

        //if(s.equals("FINE")) return Level.FINE;
        if (s.equals("WARNING")) {
            return WARNING;
        }

        if (s.equals("INFO")) {
            return INFO;
        }

        if (s.equals("CONFI")) {
            return CONFIG;
        }

        if (s.equals("FINE")) {
            return FINE;
        }

        if (s.equals("FINER")) {
            return FINER;
        }

        if (s.equals("FINEST")) {
            return FINEST;
        }
        return defaultLevel;
    }

}

⏎ org/apache/log4j/helpers/UtilLoggingLevel.java

Or download all of them as a single archive file:

File name: log4j-1.2.17-sources.jar
File size: 481200 bytes
Release date: 2012-05-06
Download 

⇒ Download and Install apache-log4j-1.2.15.zip

⇐ Download and Install log4j-1.2.17.zip

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