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

Bytecode (Java 8) for Apache Log4j API is provided in a separate JAR file like log4j-api-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 API 2.14.1 below.

⏎ org/apache/logging/log4j/util/Chars.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.util;

/**
 * <em>Consider this class private.</em>
 */
public final class Chars {

    /** Carriage Return. */
    public static final char CR = '\r';

    /** Double Quote. */
    public static final char DQUOTE = '\"';

    /** Equals '='. */
    public static final char EQ = '=';

    /** Line Feed. */
    public static final char LF = '\n';

    /** NUL. */
	public static final char NUL = 0;

	/** Single Quote [']. */
    public static final char QUOTE = '\'';

    /** Space. */
    public static final char SPACE = ' ';

    /** Tab. */
    public static final char TAB = '\t';

    /**
     * Converts a digit into an upper-case hexadecimal character or the null character if invalid.
     *
     * @param digit a number 0 - 15
     * @return the hex character for that digit or '\0' if invalid
     */
    public static char getUpperCaseHex(final int digit) {
        if (digit < 0 || digit >= 16) {
            return '\0';
        }
        return digit < 10 ? getNumericalDigit(digit) : getUpperCaseAlphaDigit(digit);
    }

    /**
     * Converts a digit into an lower-case hexadecimal character or the null character if invalid.
     *
     * @param digit a number 0 - 15
     * @return the hex character for that digit or '\0' if invalid
     */
    public static char getLowerCaseHex(final int digit) {
        if (digit < 0 || digit >= 16) {
            return '\0';
        }
        return digit < 10 ? getNumericalDigit(digit) : getLowerCaseAlphaDigit(digit);
    }

    private static char getNumericalDigit(final int digit) {
        return (char) ('0' + digit);
    }

    private static char getUpperCaseAlphaDigit(final int digit) {
        return (char) ('A' + digit - 10);
    }

    private static char getLowerCaseAlphaDigit(final int digit) {
        return (char) ('a' + digit - 10);
    }

    private Chars() {
    }
}

⏎ org/apache/logging/log4j/util/Chars.java

Or download all of them as a single archive file:

File name: log4j-api-2.14.1-sources.jar
File size: 264773 bytes
Release date: 2021-03-06
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