com.petpet.c3po.gatherer.FileExtractor.java Source code

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Here is the source code for com.petpet.c3po.gatherer.FileExtractor.java

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/*******************************************************************************
 * Copyright 2013 Petar Petrov <me@petarpetrov.org>
 * 
 * Licensed 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 com.petpet.c3po.gatherer;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.GZIPInputStream;

import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.ArchiveInputStream;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

// Thanks to: https://gist.github.com/johnkil/4345164
/**
 * Extracts different archive files with apache commons compress.
 * 
 * @author Petar Petrov <me@petarpetrov.org>
 * 
 */
public class FileExtractor {

    /**
     * Default logger.
     */
    private static final Logger LOG = LoggerFactory.getLogger(FileExtractor.class);

    /**
     * The buffer size used for IO operations.
     */
    private static final int BUFFER_SIZE = 8 * 1024;

    /**
     * Extracts the given archive file to the given destination folder.
     * 
     * @param src
     *          the file to extract.
     * @param dst
     *          the destination folder.
     */
    public static void extract(String src, String dst) {

        ArchiveInputStream is = getStream(src);
        extract(is, new File(dst));

    }

    /**
     * Unpack data from the stream to specified directory.
     * 
     * @param in
     *          stream with tar data
     * @param outputDir
     *          destination directory
     * @return true in case of success, otherwise - false
     */
    private static void extract(ArchiveInputStream in, File outputDir) {
        try {
            ArchiveEntry entry;
            while ((entry = in.getNextEntry()) != null) {
                // replace : for windows OS.
                final File file = new File(outputDir, entry.getName().replaceAll(":", "_"));

                if (entry.isDirectory()) {

                    if (!file.exists()) {
                        file.mkdirs();
                    }

                } else {
                    file.getParentFile().mkdirs();
                    BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(file), BUFFER_SIZE);

                    try {

                        IOUtils.copy(in, out);
                        out.flush();

                    } finally {
                        try {
                            out.close();

                        } catch (IOException e) {
                            LOG.debug("An error occurred while closing the output stream for file '{}'. Error: {}",
                                    file, e.getMessage());
                        }
                    }
                }
            }

        } catch (IOException e) {
            LOG.debug("An error occurred while handling archive file. Error: {}", e.getMessage());
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    LOG.debug("An error occurred while closing the archive stream . Error: {}", e.getMessage());
                }
            }
        }
    }

    /**
     * Obtains an apache compress {@link ArchiveInputStream} to the given archive
     * file.
     * 
     * @param src
     *          the archive file.
     * @return the stream.
     */
    private static ArchiveInputStream getStream(String src) {
        FileInputStream fis = null;
        ArchiveInputStream is = null;

        try {

            fis = new FileInputStream(src);

            if (src.endsWith(".zip")) {

                is = new ZipArchiveInputStream(fis);

            } else {

                boolean zip = src.endsWith(".tgz") || src.endsWith(".gz");
                InputStream imp = (zip) ? new GZIPInputStream(fis, BUFFER_SIZE)
                        : new BufferedInputStream(fis, BUFFER_SIZE);
                is = new TarArchiveInputStream(imp, BUFFER_SIZE);

            }

        } catch (IOException e) {
            LOG.warn("An error occurred while obtaining the stream to the archive '{}'. Error: {}", src,
                    e.getMessage());
        }
        return is;
    }
}