org.formic.util.Extractor.java Source code

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Here is the source code for org.formic.util.Extractor.java

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/**
 * Formic installer framework.
 * Copyright (C) 2005 - 2010  Eric Van Dewoestine
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package org.formic.util;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import java.util.Enumeration;

import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;

/**
 * Handles extraction of zip resources.
 *
 * @author Eric Van Dewoestine
 */
public class Extractor {
    /**
     * Reads an archive from the classpath and extracts it to the specified
     * destination.
     *
     * @param resource The resource representing the archive.
     * @param dest The destination to extract the archive to.
     */
    public static void extractResource(String resource, File dest) throws IOException {
        File archive = File.createTempFile(FilenameUtils.getBaseName(resource),
                "." + FilenameUtils.getExtension(resource));
        Extractor.readArchive(resource, archive);
        Extractor.extractArchive(archive, dest, null);

        // delete temp archive.
        archive.delete();
    }

    /**
     * Reads an archive from the classpath and writes it to the specified
     * destination.
     *
     * @param resource The resource representing the archive.
     * @param dest The destination to write the archive to.
     */
    public static void readArchive(String resource, File dest) throws IOException {
        FileOutputStream out = null;
        InputStream in = null;
        try {
            out = new FileOutputStream(dest);
            in = Extractor.class.getResourceAsStream(resource);

            if (in == null) {
                throw new IOException("Resource not found: " + resource);
            }

            IOUtils.copy(in, out);

            in.close();
            out.close();
        } finally {
            IOUtils.closeQuietly(in);
            IOUtils.closeQuietly(out);
        }
    }

    /**
     * Extracts the specified archive to the supplied destination.
     *
     * @param archive The archive to extract.
     * @param dest The directory to extract it to.
     */
    public static void extractArchive(File archive, File dest, ArchiveExtractionListener listener)
            throws IOException {
        ZipFile file = null;
        try {
            file = new ZipFile(archive);

            if (listener != null) {
                listener.startExtraction(file.size());
            }

            Enumeration entries = file.entries();
            for (int ii = 0; entries.hasMoreElements(); ii++) {
                ZipEntry entry = (ZipEntry) entries.nextElement();
                if (!entry.isDirectory()) {
                    // create parent directories if necessary.
                    String name = dest + "/" + entry.getName();
                    if (name.indexOf('/') != -1) {
                        File dir = new File(name.substring(0, name.lastIndexOf('/')));
                        if (!dir.exists()) {
                            dir.mkdirs();
                        }
                    }

                    if (listener != null) {
                        listener.startExtractingFile(ii, entry.getName());
                    }

                    FileOutputStream out = new FileOutputStream(name);
                    InputStream in = file.getInputStream(entry);

                    IOUtils.copy(in, out);

                    in.close();
                    out.close();

                    if (listener != null) {
                        listener.finishExtractingFile(ii, entry.getName());
                    }
                }
            }
        } finally {
            try {
                file.close();
            } catch (Exception ignore) {
            }
        }

        if (listener != null) {
            listener.finishExtraction();
        }
    }

    /**
     * Listener that can be notified of significant events when extracting an
     * archive.
     */
    public static interface ArchiveExtractionListener {
        /**
         * Invoked just before beginning to extract files.
         *
         * @param count The number of files to be extracted.
         */
        public void startExtraction(int count);

        /**
         * Invoked after all files have been extracted.
         */
        public void finishExtraction();

        /**
         * Invoked when the supplied file is to be extracted.
         *
         * @param index The index of the file within the archive.
         * @param file The file name.
         */
        public void startExtractingFile(int index, String file);

        /**
         * Invoked when the supplied file has been completely extracted.
         *
         * @param index The index of the file within the archive.
         * @param file The file name.
         */
        public void finishExtractingFile(int index, String file);
    }
}