org.ecoinformatics.seek.datasource.EcogridZippedDataCacheItem.java Source code

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Here is the source code for org.ecoinformatics.seek.datasource.EcogridZippedDataCacheItem.java

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/*
 * Copyright (c) 2004-2010 The Regents of the University of California.
 * All rights reserved.
 *
 * '$Author: welker $'
 * '$Date: 2010-05-05 22:21:26 -0700 (Wed, 05 May 2010) $' 
 * '$Revision: 24234 $'
 * 
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the above
 * copyright notice and the following two paragraphs appear in all copies
 * of this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 * THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
 * CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
 * ENHANCEMENTS, OR MODIFICATIONS.
 *
 */

package org.ecoinformatics.seek.datasource;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

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

/**
 * This class represents a zip data object. When the object downloaded, it will
 * be unzipped into a sub cache directory
 * 
 * @author Jing Tao
 * 
 */

public class EcogridZippedDataCacheItem extends EcogridCompressedDataCacheItem {
    private static Log log;
    static {
        log = LogFactory.getLog("org.ecoinformatics.seek.datasource.EcogridZippedDataCacheItem");
    }

    /**
     * Default constructor
     */
    public EcogridZippedDataCacheItem() {
        super();
    }

    /**
     * Constructor
     * 
     * @param refresh
     *            if the compressed file need be uncompressed again even already
     *            has umpressed before
     */
    public EcogridZippedDataCacheItem(boolean refresh) {
        super(refresh);
    }

    /**
     * This method overwirtes the super class. It is specified to unzip a zip
     * file
     * 
     * @throws Exception
     */
    public void unCompressCacheItem() throws Exception {
        if (unCompressedCacheItemDir != null) {
            log.debug("At unCompressCacheItem method in Zip ojbect");
            ZipFile zipFile = new ZipFile(getAbsoluteFileName());
            Enumeration enu = zipFile.entries();
            // go though every zip entry
            byte[] array = new byte[300 * 1024];
            while (enu.hasMoreElements()) {
                ZipEntry entry = (ZipEntry) enu.nextElement();
                // write zipEntry to a local file in
                // Cachedir/unzip/mlocatFilename/
                String name = entry.getName();
                if (name != null) {
                    log.debug("Zip entry name is " + name);
                    File unzipFile = new File(unCompressedCacheItemDir, name);
                    FileOutputStream fileWriter = new FileOutputStream(unzipFile);
                    InputStream fileReader = zipFile.getInputStream(entry);
                    int len;
                    while ((len = fileReader.read(array)) >= 0) {
                        fileWriter.write(array, 0, len);
                    }
                    fileReader.close();
                    fileWriter.close();
                }
            }
            unCompressedFileList = unCompressedCacheItemDir.list();
        }

    }

}