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/util/NullOutputStream.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.util;

import java.io.IOException;
import java.io.OutputStream;

/**
 * Writes all data to the famous <b>/dev/null</b>.
 * <p>
 * This output stream has no destination (file/socket etc.) and all bytes written to it are ignored and lost.
 * </p>
 * Originally from Apache Commons IO.
 *
 * @since 2.3
 */
public class NullOutputStream extends OutputStream {

    private static final NullOutputStream INSTANCE = new NullOutputStream();

    /**
     * @deprecated Deprecated in 2.7: use {@link #getInstance()}.
     */
    @Deprecated
    public static final NullOutputStream NULL_OUTPUT_STREAM = INSTANCE;

    /**
     * Gets the singleton instance.
     *
     * @return the singleton instance.
     */
    public static NullOutputStream getInstance() {
        return INSTANCE;
    }

    private NullOutputStream() {
        // do nothing
    }

    /**
     * Does nothing - output to <code>/dev/null</code>.
     *
     * @param b
     *        The bytes to write
     * @param off
     *        The start offset
     * @param len
     *        The number of bytes to write
     */
    @Override
    public void write(final byte[] b, final int off, final int len) {
        // to /dev/null
    }

    /**
     * Does nothing - output to <code>/dev/null</code>.
     *
     * @param b
     *        The byte to write
     */
    @Override
    public void write(final int b) {
        // to /dev/null
    }

    /**
     * Does nothing - output to <code>/dev/null</code>.
     *
     * @param b
     *        The bytes to write
     * @throws IOException
     *         never
     */
    @Override
    public void write(final byte[] b) throws IOException {
        // to /dev/null
    }
}

⏎ org/apache/logging/log4j/core/util/NullOutputStream.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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