Apache Log4j Core Implementation provides the functional components of the logging system. Users are free to create their own plugins and include them in the logging configuration. Apache Log4j Core is a required module to use Apache Log4j.

Bytecode (Java 8) for Apache Log4j Core Implementation is provided in a separate JAR file like log4j-core-2.14.1.jar.

Source Code files for Apache Log4j API are provided in both binary packge like apache-log4j-2.14.1-bin.zip and source package like apache-log4j-2.14.1-src.zip. You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j Core Implementation 2.14.1 below.

⏎ org/apache/logging/log4j/core/net/Severity.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.logging.log4j.core.net;

import org.apache.logging.log4j.Level;

/**
 *  Severity values used by the Syslog system.
 *
 * <table summary="Syslog Severity Values">
 *     <tr>
 *         <th>Numerical Code</th>
 *         <th>Severity</th>
 *     </tr>
 *     <tr>
 *         <td>0</td>
 *         <td>Emergency: system is unusable</td>
 *     </tr>
 *     <tr>
 *         <td>1</td>
 *         <td>Alert: action must be taken immediately</td>
 *     </tr>
 *     <tr>
 *         <td>2</td>
 *         <td>Critical: critical conditions</td>
 *     </tr>
 *     <tr>
 *         <td>3</td>
 *         <td>Error: error conditions</td>
 *     </tr>
 *     <tr>
 *         <td>4</td>
 *         <td>Warning: warning conditions</td>
 *     </tr>
 *     <tr>
 *         <td>5</td>
 *         <td>Notice: normal but significant condition</td>
 *     </tr>
 *     <tr>
 *         <td>6</td>
 *         <td>Informational: informational messages</td>
 *     </tr>
 *     <tr>
 *         <td>7</td>
 *         <td>Debug: debug-level messages</td>
 *     </tr>
 * </table>
 */
public enum Severity {
    /** System is unusable. */
    EMERG(0),
    /** Action must be taken immediately. */
    ALERT(1),
    /** Critical conditions. */
    CRITICAL(2),
    /** Error conditions. */
    ERROR(3),
    /** Warning conditions. */
    WARNING(4),
    /** Normal but significant conditions. */
    NOTICE(5),
    /** Informational messages. */
    INFO(6),
    /** Debug level messages. */
    DEBUG(7);

    private final int code;

    Severity(final int code) {
        this.code = code;
    }

    /**
     * Returns the severity code.
     * @return The numeric value associated with the Severity.
     */
    public int getCode() {
        return this.code;
    }

    /**
     * Determine if the name matches this Severity.
     * @param name the name to match.
     * @return true if the name matches, false otherwise.
     */
    public boolean isEqual(final String name) {
        return this.name().equalsIgnoreCase(name);
    }

    /**
     * Returns the Severity for the specified Level.
     * @param level The Level.
     * @return The matching Severity, or DEBUG if there is no match.
     */
    public static Severity getSeverity(final Level level) {
        switch (level.getStandardLevel()) {
            case ALL:
                return DEBUG;
            case TRACE:
                return DEBUG;
            case DEBUG:
                return DEBUG;
            case INFO:
                return INFO;
            case WARN:
                return WARNING;
            case ERROR:
                return ERROR;
            case FATAL:
                return ALERT;
            case OFF:
                return EMERG;
        }
        return DEBUG;
    }
}

⏎ org/apache/logging/log4j/core/net/Severity.java

Or download all of them as a single archive file:

File name: log4j-core-2.14.1-sources.jar
File size: 1281358 bytes
Release date: 2021-03-06
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