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/appender/rolling/action/GzCompressAction.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.appender.rolling.action;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Objects;
import java.util.zip.Deflater;
import java.util.zip.GZIPOutputStream;

/**
 * Compresses a file using GZ compression.
 */
public final class GzCompressAction extends AbstractAction {

    private static final int BUF_SIZE = 8192;

    /**
     * Source file.
     */
    private final File source;

    /**
     * Destination file.
     */
    private final File destination;

    /**
     * If true, attempt to delete file on completion.
     */
    private final boolean deleteSource;

    /**
     * GZIP compression level to use.
     *
     * @see Deflater#setLevel(int)
     */
    private final int compressionLevel;

    /**
     * Create new instance of GzCompressAction.
     *
     * @param source       file to compress, may not be null.
     * @param destination  compressed file, may not be null.
     * @param deleteSource if true, attempt to delete file on completion.  Failure to delete
     *                     does not cause an exception to be thrown or affect return value.
     * @param compressionLevel
     *                     Gzip deflater compression level.
     */
    public GzCompressAction(
            final File source, final File destination, final boolean deleteSource, final int compressionLevel) {
        Objects.requireNonNull(source, "source");
        Objects.requireNonNull(destination, "destination");

        this.source = source;
        this.destination = destination;
        this.deleteSource = deleteSource;
        this.compressionLevel = compressionLevel;
    }

    /**
     * Prefer the constructor with compression level.
     *
     * @deprecated Prefer {@link GzCompressAction#GzCompressAction(File, File, boolean, int)}.
     */
    @Deprecated
    public GzCompressAction(final File source, final File destination, final boolean deleteSource) {
        this(source, destination, deleteSource, Deflater.DEFAULT_COMPRESSION);
    }

    /**
     * Compress.
     *
     * @return true if successfully compressed.
     * @throws IOException on IO exception.
     */
    @Override
    public boolean execute() throws IOException {
        return execute(source, destination, deleteSource, compressionLevel);
    }

    /**
     * Compress a file.
     *
     * @param source       file to compress, may not be null.
     * @param destination  compressed file, may not be null.
     * @param deleteSource if true, attempt to delete file on completion.  Failure to delete
     *                     does not cause an exception to be thrown or affect return value.
     * @return true if source file compressed.
     * @throws IOException on IO exception.
     * @deprecated In favor of {@link #execute(File, File, boolean, int)}.
     */
    @Deprecated
    public static boolean execute(final File source, final File destination, final boolean deleteSource)
            throws IOException {
        return execute(source, destination, deleteSource, Deflater.DEFAULT_COMPRESSION);
    }

    /**
     * Compress a file.
     *
     * @param source       file to compress, may not be null.
     * @param destination  compressed file, may not be null.
     * @param deleteSource if true, attempt to delete file on completion.  Failure to delete
     *                     does not cause an exception to be thrown or affect return value.
     * @param compressionLevel
     *                     Gzip deflater compression level.
     * @return true if source file compressed.
     * @throws IOException on IO exception.
     */
    public static boolean execute(
            final File source,
            final File destination,
            final boolean deleteSource,
            final int compressionLevel) throws IOException {
        if (source.exists()) {
            try (final FileInputStream fis = new FileInputStream(source);
                 final OutputStream fos = new FileOutputStream(destination);
                 final OutputStream gzipOut = new ConfigurableLevelGZIPOutputStream(
                         fos, BUF_SIZE, compressionLevel);
                 // Reduce native invocations by buffering data into GZIPOutputStream
                 final OutputStream os = new BufferedOutputStream(gzipOut, BUF_SIZE)) {
                final byte[] inbuf = new byte[BUF_SIZE];
                int n;

                while ((n = fis.read(inbuf)) != -1) {
                    os.write(inbuf, 0, n);
                }
            }

            if (deleteSource && !source.delete()) {
                LOGGER.warn("Unable to delete {}.", source);
            }

            return true;
        }

        return false;
    }

    private static final class ConfigurableLevelGZIPOutputStream extends GZIPOutputStream {

        ConfigurableLevelGZIPOutputStream(OutputStream out, int bufSize, int level) throws IOException {
            super(out, bufSize);
            def.setLevel(level);
        }
    }

    /**
     * Capture exception.
     *
     * @param ex exception.
     */
    @Override
    protected void reportException(final Exception ex) {
        LOGGER.warn("Exception during compression of '" + source.toString() + "'.", ex);
    }

    @Override
    public String toString() {
        return GzCompressAction.class.getSimpleName() + '[' + source + " to " + destination
                + ", deleteSource=" + deleteSource + ']';
    }

    public File getSource() {
        return source;
    }

    public File getDestination() {
        return destination;
    }

    public boolean isDeleteSource() {
        return deleteSource;
    }
}

⏎ org/apache/logging/log4j/core/appender/rolling/action/GzCompressAction.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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