com.celements.photo.utilities.Unzip.java Source code

Introduction

Here is the source code for com.celements.photo.utilities.Unzip.java

Source

/*
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This 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 software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package com.celements.photo.utilities;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.xpn.xwiki.XWikiException;

public class Unzip {
    private static final int BUFFER = 1024;

    private static Log mLogger = LogFactory.getFactory().getInstance(Unzip.class);

    public Unzip() {
    }

    /**
     * Extracts the specified file from a given zip archive.
     * 
     * @param zipFile byte array representation of a zip archive.
     * @param filename Name of the file which should be extracted.
     * @return A ByteArrayOutputStream of the extractes file.
     * @throws XWikiException
     * @throws IOException
     */
    public ByteArrayOutputStream getFile(byte[] zipFile, String filename) throws XWikiException, IOException {
        return findAndExtractFile(filename, getZipInputStream(zipFile));
    }

    private ByteArrayOutputStream findAndExtractFile(String filename, ZipInputStream zipIn) throws IOException {
        ByteArrayOutputStream out = null;

        for (ZipEntry entry = zipIn.getNextEntry(); zipIn.available() > 0; entry = zipIn.getNextEntry()) {
            if (!entry.isDirectory() && entry.getName().equals(filename)) {
                // read the data and write it to the OutputStream
                int count;
                byte[] data = new byte[BUFFER];
                out = new ByteArrayOutputStream();
                BufferedOutputStream byteOut = new BufferedOutputStream(out, BUFFER);
                while ((count = zipIn.read(data, 0, BUFFER)) != -1) {
                    byteOut.write(data, 0, count);
                }
                byteOut.flush();
                break;
            }
        }

        zipIn.close();
        return out;
    }

    /**
     * Get a List of names of all files contained in the zip file.
     * 
     * @param zipFile byte array of the zip file.
     * @return List of all filenames (and directory names - ending with a file seperator) contained in the zip file.
     */
    public List<String> getZipContentList(byte[] zipFile) {
        String fileSep = System.getProperty("file.separator");
        List<String> contentList = new ArrayList<String>();
        ZipInputStream zipStream = getZipInputStream(zipFile);

        try {
            while (zipStream.available() > 0) {
                ZipEntry entry = zipStream.getNextEntry();
                if (entry != null) {
                    String fileName = entry.getName();
                    if (entry.isDirectory() && !fileName.endsWith(fileSep)) {
                        fileName += fileSep;
                    }
                    contentList.add(fileName);
                }
            }
        } catch (IOException e) {
            mLogger.error(e);
        }

        return contentList;
    }

    /*
     * Get a ZiInputStream for the specified file.
     * 
     * @param srcFile byte array representation of a zip file.
     * @return A ZipInputStream for the file.
     */
    private ZipInputStream getZipInputStream(byte[] srcFile) {
        ByteArrayInputStream in = new ByteArrayInputStream(srcFile);
        return new ZipInputStream(new BufferedInputStream(in));
    }
}