Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*   Copyright (C) 2015 Marius C. Silaghi
 Author: Marius Silaghi: msilaghi@fit.edu
 Florida Tech, Human Decision Support Systems Laboratory
    
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published by
 the Free Software Foundation; either the current version 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 Affero General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.              */

import java.math.BigInteger;

import java.util.ArrayList;

public class Main {
    public final static BigInteger BN127 = new BigInteger("127");

    /**
     * This is based on bit shifting (using base128()).
     * Returns array of bytes.
     * @param val
     * @return
     */
    public static byte[] toBase_128(BigInteger val) {
        ArrayList<Integer> al = base128(val);
        byte[] result = new byte[al.size()];
        for (int k = 0; k < result.length; k++)
            result[k] = al.get(k).byteValue();
        ;
        return result;
    }

    /**
     * Convert to base 128 (bigendian), using shifts.
     * @param val
     * @return
     */
    public static ArrayList<Integer> base128(BigInteger val) {
        ArrayList<Integer> result = new ArrayList<Integer>();
        int part = val.and(BN127).intValue();
        val = val.shiftRight(7);
        result.add(0, new Integer(part));
        while (!val.equals(BigInteger.ZERO)) {
            part = val.and(BN127).intValue();
            val = val.shiftRight(7);
            part += 128;
            result.add(0, new Integer(part));
        }
        ;
        return result;
    }
}