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

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Here is the source code for org.ecoinformatics.seek.datasource.EcogridGZippedDataCacheItem.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.FileInputStream;
import java.io.FileOutputStream;
import java.util.zip.GZIPInputStream;

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

/**
 * This class reprents a gzipped cache item, it will run gunzip to uncompressed
 * this data object
 * 
 * @author Jing Tao
 * 
 */
public class EcogridGZippedDataCacheItem extends EcogridCompressedDataCacheItem {
    private static Log log;
    static {
        log = LogFactory.getLog("org.ecoinformatics.seek.datasource.EcogridGZippedDataCacheItem");
    }

    /**
     * Default constructor for this object
     */
    public EcogridGZippedDataCacheItem() {
        super();
    }

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

    /**
     * This method overwrite the super class - EcogridCompressedDataCacheItem.
     * It specifys the gunzip method to uncompress the file. The new ungzip file
     * will be the the cacheitem file name without the file extension. An file
     * location will be the cachedata/unzip/cacheitemname/ If this is tar file
     * too, we will untar it after ungzip it.
     * 
     * @throws Exception
     */
    public void unCompressCacheItem() throws Exception {
        if (unCompressedFilePath != null) {
            log.debug("At unCompressCacheItem method in Zip ojbect");
            // read the gzip file and ungzip it
            GZIPInputStream gZipFileReader = new GZIPInputStream(new FileInputStream(getFile()));
            String unGZipFileName = removeFileExtension(getAbsoluteFileName());
            String unGZipFilePath = unCompressedFilePath + File.separator + unGZipFileName;
            log.debug("The unGzip aboslute file path is " + unGZipFilePath);
            File unGzipFile = new File(unGZipFilePath);
            FileOutputStream fileWriter = new FileOutputStream(unGzipFile);
            byte[] array = new byte[3000 * 1024];
            int len;
            while ((len = gZipFileReader.read(array)) >= 0) {
                fileWriter.write(array, 0, len);
            }
            gZipFileReader.close();
            fileWriter.close();
            // if this is a tar file too, will untar it.
            if (getIsTarFile()) {
                if (unCompressedFilePath != null) {
                    log.debug("untar the file after ungzip");
                    EcogridTarArchivedDataCacheItem.extractTarFile(unGZipFilePath, unCompressedCacheItemDir);
                }
            }
            unCompressedFileList = unCompressedCacheItemDir.list();
        }
    }

    /*
     * Given a file name, this method will remove file extension. If no file
     * extension the given string will be returned.
     */
    private String removeFileExtension(String fileName) {
        String newFileName = null;
        if (fileName != null) {
            int lastDotIndex = fileName.lastIndexOf(".");
            if (lastDotIndex != -1) {
                newFileName = fileName.substring(0, lastDotIndex);
            } else {
                newFileName = fileName;
            }
        }
        log.debug("The ungzip file name will be " + newFileName);
        return newFileName;
    }

}