net.ulno.jpunch.util.Util.java Source code

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Here is the source code for net.ulno.jpunch.util.Util.java

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/***************************************************************************
 *   Filename: Util.java
 *   Author: artjom.lind@ut.ee
 ***************************************************************************
 *   Copyright (C) 2009 by Ulrich Norbisrath
 *   devel@mail.ulno.net
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library 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 Library General Public
 *   License along with this program; if not, write to the
 *   Free Software Foundation, Inc.,
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 ***************************************************************************
 *   Description:
 *   For handling the serialization and compression
 ***************************************************************************/
package net.ulno.jpunch.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.StreamCorruptedException;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import org.apache.commons.codec.binary.Base64;

/**
 * For handling the serialization and compression
 * @author artjom.lind@ut.ee
 *
 */
public abstract class Util {
    /**
     * Serializes Object into byte array.
     * @throws IOException 
     */
    public static byte[] serializeObject(Object obj) throws IOException {
        ByteArrayOutputStream os = new ByteArrayOutputStream();

        ObjectOutput oo;
        oo = new ObjectOutputStream(os);
        oo.writeObject(obj);

        return os.toByteArray();
    }

    /**
     * Deserializes Object from byte array.
     * @throws IOException 
     * @throws StreamCorruptedException 
     * @throws ClassNotFoundException 
     */
    public static Object deserializeObject(byte[] serializedObj)
            throws StreamCorruptedException, IOException, ClassNotFoundException {
        InputStream is = new ByteArrayInputStream(serializedObj);
        ObjectInput oi;
        oi = new ObjectInputStream(is);
        return oi.readObject();
    }

    public static byte[] zip(byte[] data) throws IOException {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        GZIPOutputStream gz = new GZIPOutputStream(os);
        gz.write(data);
        gz.finish();
        return os.toByteArray();
    }

    public static byte[] unzip(byte[] data) throws IOException {
        InputStream is = new ByteArrayInputStream(data);
        GZIPInputStream gz = new GZIPInputStream(is);
        List<Byte> l = new ArrayList<Byte>();
        while (gz.available() != 0)
            l.add((byte) gz.read());
        // last byte is unnecessary (it is -1)
        byte[] uncmp = new byte[l.size() - 1];
        for (int i = 0; i < l.size() - 1; i++)
            uncmp[i] = l.get(i);
        return uncmp;
    }

    /**
     * Encodes byte array into String.
     */
    public static String encode(byte[] bytes) {
        return new String(Base64.encodeBase64(bytes));
    }

    /**
     * Decodes byte array from String.
     */
    public static byte[] decode(String str)
    //   throws MessageCreateException
    {
        return Base64.decodeBase64(str.getBytes());
    }

    /**
     * Returns transfer speed,
     * computed using start/stop time stamps in milliseconds and
     * transfered amount of data in bytes  
     * 
     * @param start
     * @param stop
     * @param size
     * @return
     */
    public static double getTransferSpeed(long start, long stop, int size) {
        long time = stop - start;
        double secs = time * 1.0 / 1000;
        double kbytes = size * 1.0 / 1024;
        return kbytes / secs;
    }

    public static String getTransferStat(long start, long stop, int size) {
        long time = stop - start;
        double secs = time * 1.0 / 1000;
        double kbytes = size * 1.0 / 1024;
        double speed = kbytes / secs;
        StringBuffer sb = new StringBuffer();
        sb.append("\nTransfer Statistics:\n");
        sb.append(String.format("\tTransfer completed in [%s] sec\n", secs));
        sb.append(String.format("\tTransfered size is [%s] %s\n", kbytes >= 1024 ? kbytes / 1024 : kbytes,
                kbytes >= 1024 ? "mbytes" : "kbytes"));
        sb.append(String.format("\tAverage speed is [%s] kbytes/s\n", speed));
        return sb.toString();
    }
}