com.bahmanm.karun.Utils.java Source code

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Here is the source code for com.bahmanm.karun.Utils.java

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/*
 * Karun, a package manager for ArchLinux based on 'pacman'.
 * Copyright (C) 2011  Bahman Movaqar
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.
 */
package com.bahmanm.karun;

import java.awt.Frame;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;
import org.apache.commons.compress.archivers.ArchiveException;
import org.apache.commons.compress.archivers.ArchiveInputStream;
import org.apache.commons.compress.archivers.ArchiveStreamFactory;
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
import org.apache.commons.compress.utils.IOUtils;

/**
 * Utils
 *
 * @author Bahman Movaqar (Bahman AT BahmanM.com)
 */
public class Utils {

    /**
     * Copies srcPath to destPath.
     * 
     * @param srcPath Path to source file
     * @param destPath Path to destination file
     * @throws FileNotFoundException
     * @throws IOException 
     */
    public synchronized static void copyFile(String srcPath, String destPath)
            throws FileNotFoundException, IOException {
        FileInputStream in = new FileInputStream(srcPath);
        FileOutputStream out = new FileOutputStream(destPath);
        IOUtils.copy(in, out);
        in.close();
        out.close();
    }

    /**
     * Extracts a gzip'ed tar archive.
     * 
     * @param archivePath Path to archive
     * @param destDir Destination directory
     * @throws IOException 
     */
    public synchronized static void extractTarGz(String archivePath, File destDir)
            throws IOException, ArchiveException {
        // copy
        File tarGzFile = File.createTempFile("karuntargz", "", destDir);
        copyFile(archivePath, tarGzFile.getAbsolutePath());

        // decompress
        File tarFile = File.createTempFile("karuntar", "", destDir);
        FileInputStream fin = new FileInputStream(tarGzFile);
        BufferedInputStream bin = new BufferedInputStream(fin);
        FileOutputStream fout = new FileOutputStream(tarFile);
        GzipCompressorInputStream gzIn = new GzipCompressorInputStream(bin);
        final byte[] buffer = new byte[1024];
        int n = 0;
        while (-1 != (n = gzIn.read(buffer))) {
            fout.write(buffer, 0, n);
        }
        bin.close();
        fin.close();
        gzIn.close();
        fout.close();

        // extract
        final InputStream is = new FileInputStream(tarFile);
        ArchiveInputStream ain = new ArchiveStreamFactory().createArchiveInputStream("tar", is);
        TarArchiveEntry entry = null;
        while ((entry = (TarArchiveEntry) ain.getNextEntry()) != null) {
            OutputStream out;
            if (entry.isDirectory()) {
                File f = new File(destDir, entry.getName());
                f.mkdirs();
                continue;
            } else
                out = new FileOutputStream(new File(destDir, entry.getName()));
            IOUtils.copy(ain, out);
            out.close();
        }
        ain.close();
        is.close();
    }

    /**
     * Pops up a dialog containing useful information from exception such as
     * stack trace.
     * 
     * @param parent Parent component
     * @param ex Exception
     */
    public static void showExceptionDialog(Frame parent, Exception ex) {
        String topic = "";
        if (ex instanceof IOException)
            topic = "An I/O error occured.";
        else
            topic = "An error occured.";
        topic += "  [" + ex.getClass().getName() + "]";
        if (ex.getMessage() != null)
            topic += "\n" + ex.getMessage();

        StackTraceElement[] stackTrace = ex.getStackTrace();
        String stacktraceStr = "";
        for (int i = 0; i < stackTrace.length; i++)
            stacktraceStr += stackTrace[i] + "\n";

        ExceptionDialog edialog = new ExceptionDialog(parent, true, topic, stacktraceStr);
        edialog.setVisible(true);
    }

    /**
     * Creates a temporary directory.
     * 
     * @return Temporary directory
     */
    public static File createTempDir() throws IOException {
        //final File sysTempDir = new File(System.getProperty("java.io.tmpdir"));
        File newTempDir;
        final int maxAttempts = 9;
        int attemptCount = 0;
        do {
            attemptCount++;
            if (attemptCount > maxAttempts) {
                throw new IOException("Failed to create a unique temporary directory.");
            }
            String dirName = UUID.randomUUID().toString();
            newTempDir = new File("/tmp/karun/", dirName);
        } while (newTempDir.exists());

        if (newTempDir.mkdirs()) {
            return newTempDir;
        } else {
            throw new IOException("Failed to create temporary directory named " + newTempDir.getAbsolutePath());
        }
    }
}