Zip.java

//----------------------------------------------------------------------------//
//                                                                            //
//                                   Z i p                                    //
//                                                                            //
//----------------------------------------------------------------------------//
// <editor-fold defaultstate="collapsed" desc="hdr">                          //
//  Copyright © Hervé Bitteur and others 2000-2013. All rights reserved.      //
//  This software is released under the GNU General Public License.           //
//  Goto http://kenai.com/projects/audiveris to report bugs or suggestions.   //
//----------------------------------------------------------------------------//
// </editor-fold>
package omr.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;

/**
 * Class {@code Zip} is a convenient utility that provides both
 * writing and reading from a file which is transparently compressed
 * in Zip.
 *
 * @author Hervé Bitteur
 */
public class Zip
{
    //~ Constructors -----------------------------------------------------------

    private Zip ()
    {
    }

    //~ Methods ----------------------------------------------------------------
    //--------------------//
    // createInputStream //
    //-------------------//
    /**
     * Create a InputStream on a given file, by looking for a zip
     * archive whose path is the file path with ".zip" appended,
     * and by reading the first entry in this zip file.
     *
     * @param file the file (with no zip extension)
     *
     * @return a InputStream on the zip entry
     */
    public static InputStream createInputStream (File file)
    {
        try {
            String path = file.getCanonicalPath();

            //ZipFile zf = new ZipFile(path + ".zip");
            ZipFile zf = new ZipFile(path);

            for (Enumeration<?> entries = zf.entries();
                    entries.hasMoreElements();) {
                ZipEntry entry = (ZipEntry) entries.nextElement();

                return zf.getInputStream(entry);
            }
        } catch (FileNotFoundException ex) {
            System.err.println(ex.toString());
            System.err.println(file + " not found");
        } catch (IOException ex) {
            System.err.println(ex.toString());
        }

        return null;
    }

    //--------------------//
    // createOutputStream //
    //-------------------//
    /**
     * Create a OutputStream on a given file, transparently compressing the data
     * to a Zip file whose name is the provided file path, with a ".zip"
     * extension added.
     *
     * @param file the file (with no zip extension)
     *
     * @return a OutputStream on the zip entry
     */
    public static OutputStream createOutputStream (File file)
    {
        try {
            String path = file.getCanonicalPath();
            FileOutputStream fos = new FileOutputStream(path + ".zip");
            ZipOutputStream zos = new ZipOutputStream(fos);
            ZipEntry ze = new ZipEntry(file.getName());
            zos.putNextEntry(ze);

            return zos;
        } catch (FileNotFoundException ex) {
            System.err.println(ex.toString());
            System.err.println(file + " not found");
        } catch (Exception ex) {
            System.err.println(ex.toString());
        }

        return null;
    }

    //--------------//
    // createReader //
    //--------------//
    /**
     * Create a Reader on a given file, by looking for a zip archive whose path
     * is the file path with ".zip" appended, and by reading the first entry in
     * this zip file.
     *
     * @param file the file (with no zip extension)
     *
     * @return a reader on the zip entry
     */
    public static Reader createReader (File file)
    {
        try {
            String path = file.getCanonicalPath();

            ZipFile zf = new ZipFile(path + ".zip");

            for (Enumeration<?> entries = zf.entries();
                    entries.hasMoreElements();) {
                ZipEntry entry = (ZipEntry) entries.nextElement();
                InputStream is = zf.getInputStream(entry);

                return new InputStreamReader(is);
            }
        } catch (FileNotFoundException ex) {
            System.err.println(ex.toString());
            System.err.println(file + " not found");
        } catch (IOException ex) {
            System.err.println(ex.toString());
        }

        return null;
    }

    //--------------//
    // createWriter //
    //--------------//
    /**
     * Create a Writer on a given file, transparently compressing the data to a
     * Zip file whose name is the provided file path, with a ".zip" extension
     * added.
     *
     * @param file the file (with no zip extension)
     *
     * @return a writer on the zip entry
     */
    public static Writer createWriter (File file)
    {
        try {
            String path = file.getCanonicalPath();
            FileOutputStream fos = new FileOutputStream(path + ".zip");
            ZipOutputStream zos = new ZipOutputStream(fos);
            ZipEntry ze = new ZipEntry(file.getName());
            zos.putNextEntry(ze);

            return new OutputStreamWriter(zos);
        } catch (FileNotFoundException ex) {
            System.err.println(ex.toString());
            System.err.println(file + " not found");
        } catch (Exception ex) {
            System.err.println(ex.toString());
        }

        return null;
    }
}