001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.appender.rolling.action;
018
019import java.io.BufferedOutputStream;
020import java.io.File;
021import java.io.FileInputStream;
022import java.io.FileOutputStream;
023import java.io.IOException;
024import java.util.zip.GZIPOutputStream;
025
026/**
027 * Compresses a file using GZ compression.
028 */
029public final class GzCompressAction extends AbstractAction {
030
031    private static final int BUF_SIZE = 8102;
032
033    /**
034     * Source file.
035     */
036    private final File source;
037
038    /**
039     * Destination file.
040     */
041    private final File destination;
042
043    /**
044     * If true, attempt to delete file on completion.
045     */
046    private final boolean deleteSource;
047
048    /**
049     * Create new instance of GzCompressAction.
050     *
051     * @param source       file to compress, may not be null.
052     * @param destination  compressed file, may not be null.
053     * @param deleteSource if true, attempt to delete file on completion.  Failure to delete
054     *                     does not cause an exception to be thrown or affect return value.
055     */
056    public GzCompressAction(final File source, final File destination, final boolean deleteSource) {
057        if (source == null) {
058            throw new NullPointerException("source");
059        }
060
061        if (destination == null) {
062            throw new NullPointerException("destination");
063        }
064
065        this.source = source;
066        this.destination = destination;
067        this.deleteSource = deleteSource;
068    }
069
070    /**
071     * Compress.
072     *
073     * @return true if successfully compressed.
074     * @throws IOException on IO exception.
075     */
076    @Override
077    public boolean execute() throws IOException {
078        return execute(source, destination, deleteSource);
079    }
080
081    /**
082     * Compress a file.
083     *
084     * @param source       file to compress, may not be null.
085     * @param destination  compressed file, may not be null.
086     * @param deleteSource if true, attempt to delete file on completion.  Failure to delete
087     *                     does not cause an exception to be thrown or affect return value.
088     * @return true if source file compressed.
089     * @throws IOException on IO exception.
090     */
091    public static boolean execute(final File source, final File destination, final boolean deleteSource)
092        throws IOException {
093        if (source.exists()) {
094            final FileInputStream fis = new FileInputStream(source);
095            final FileOutputStream fos = new FileOutputStream(destination);
096            final GZIPOutputStream gzos = new GZIPOutputStream(fos);
097            final BufferedOutputStream os = new BufferedOutputStream(gzos);
098            final byte[] inbuf = new byte[BUF_SIZE];
099            int n;
100
101            while ((n = fis.read(inbuf)) != -1) {
102                os.write(inbuf, 0, n);
103            }
104
105            os.close();
106            fis.close();
107
108            if (deleteSource && !source.delete()) {
109                LOGGER.warn("Unable to delete " + source.toString() + '.');
110            }
111
112            return true;
113        }
114
115        return false;
116    }
117
118
119    /**
120     * Capture exception.
121     *
122     * @param ex exception.
123     */
124    @Override
125    protected void reportException(final Exception ex) {
126        LOGGER.warn("Exception during compression of '" + source.toString() + "'.", ex);
127    }
128
129    @Override
130    public String toString() {
131        return GzCompressAction.class.getSimpleName() + '[' + source + " to " + destination //
132                + ", deleteSource=" + deleteSource + ']';
133    }
134}