es.ucm.fdi.util.archive.TarFormat.java Source code

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Here is the source code for es.ucm.fdi.util.archive.TarFormat.java

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/**
 * AC - A source-code copy detector
 *
 *     For more information please visit:  http://github.com/manuel-freire/ac
 *
 * ****************************************************************************
 *
 * This file is part of AC, version 2.0
 *
 * AC 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 3 of the License,
 * or (at your option) any later version.
 *
 * AC 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 AC.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * TarFormat.java
 *
 * Created on September 18, 2006, 6:33 PM
 *
 */

package es.ucm.fdi.util.archive;

import es.ucm.fdi.util.FileUtils;
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;

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

/**
 *
 * @author mfreire
 */
public class TarFormat implements ArchiveFormat {

    private static final byte[] tarMagic = new byte[] { 0x75, 0x73, 0x74 };
    private static final int tarMagicOffset = 257;

    private static final byte[] gzMagic = new byte[] { 0x1f, (byte) 0x8b };

    public String getArchiveExtensions() {
        return "(.*\\.tar)|(.*\\.gz)|(.*\\.tgz)";
    }

    public ArrayList<String> list(File source) throws IOException {

        ArrayList<String> paths = new ArrayList<String>();
        try (InputStream is = getTarInputStream(source);
                TarArchiveInputStream tis = new TarArchiveInputStream(is)) {
            for (TarArchiveEntry e; (e = tis.getNextTarEntry()) != null; /**/) {
                String name = FileUtils.toCanonicalPath(e.getName());
                if (e.isDirectory()) {
                    continue;
                }
                paths.add(name);
            }
        }
        return paths;
    }

    public void expand(File source, File destDir) throws IOException {

        try (InputStream is = getTarInputStream(source);
                TarArchiveInputStream tis = new TarArchiveInputStream(is)) {
            byte[] b = new byte[512];
            for (TarArchiveEntry e; (e = tis.getNextTarEntry()) != null; /**/) {

                // backslash-protection: zip format expects only 'fw' slashes
                //System.err.println("Found entry: "+e.getName());
                String name = FileUtils.toCanonicalPath(e.getName());

                if (e.isDirectory()) {
                    //log.debug("\tExtracting directory "+e.getName());
                    File dir = new File(destDir, name);
                    dir.mkdirs();
                    continue;
                }

                //System.err.println("\tExtracting file "+name);
                File outFile = new File(destDir, name);
                if (!outFile.getParentFile().exists()) {
                    outFile.getParentFile().mkdirs();
                }

                try (FileOutputStream fos = new FileOutputStream(outFile)) {
                    int len;
                    while ((len = tis.read(b)) != -1) {
                        fos.write(b, 0, len);
                    }
                }
            }
        }
    }

    private InputStream getTarInputStream(File tarFile) throws IOException {
        boolean isTar = FileUtils.startMatches(new FileInputStream(tarFile), tarMagic, tarMagicOffset);
        boolean isGz = isTar ? false : FileUtils.startMatches(new FileInputStream(tarFile), gzMagic, 0);

        if (isTar) {
            return new FileInputStream(tarFile);
        } else if (isGz) {
            try (InputStream is = new GZIPInputStream(new FileInputStream(tarFile))) {
                isTar = FileUtils.startMatches(is, tarMagic, tarMagicOffset);
            }
            if (!isTar) {
                throw new IOException("Archive is Gz, but does not contain a Tar");
            }
            return new GZIPInputStream(new FileInputStream(tarFile));
        } else {
            throw new IOException("Archive is neither Tar nor Gz");
        }
    }

    public void create(ArrayList<File> sources, File destFile, File baseDir) throws IOException {
        throw new UnsupportedOperationException("Cannot create TAR files... yet");
    }

    public int compressedSize(InputStream is) throws IOException {
        throw new UnsupportedOperationException("Fast RAR compressed size calculation not supported");
    }

    public boolean extractOne(File source, String path, File dest) throws IOException {

        try (InputStream is = getTarInputStream(source);
                TarArchiveInputStream tis = new TarArchiveInputStream(is)) {
            byte[] b = new byte[512];
            for (TarArchiveEntry e; (e = tis.getNextTarEntry()) != null; /**/) {

                // backslash-protection: zip format expects only 'fw' slashes
                //System.err.println("Found entry: "+e.getName());
                String name = FileUtils.toCanonicalPath(e.getName());

                if (!name.equals(path) || e.isDirectory()) {
                    continue;
                }

                //System.err.println("\tExtracting file "+name);
                if (!dest.getParentFile().exists()) {
                    dest.getParentFile().mkdirs();
                }

                try (FileOutputStream fos = new FileOutputStream(dest)) {
                    int len;
                    while ((len = tis.read(b)) != -1) {
                        fos.write(b, 0, len);
                    }
                    return true;
                }
            }
        }
        return false;
    }
}