Java ByteBuffer Set readBitset(ByteBuffer bb, int numbytes)

Description

Reads a series of bytes from the given buffer, turning them into a little-endian bit-set.

License

Creative Commons License

Parameter

Parameter	Description
bb	ByteBuffer to read from
numbytes	Number of bytes to read.

Return

A new BitSet with the correct areas set/unset

Declaration

public static BitSet readBitset(ByteBuffer bb, int numbytes) 

Method Source Code

//package com.java2s;
/**/*from   w  w  w  . j a va 2s.c  om*/
 * Copyright (C) 2011 Darien Hager
 *
 * This code is part of the "HL2Parse" project, and is licensed under
 * a Creative Commons Attribution-ShareAlike 3.0 Unported License. For
 * either a summary of conditions or the full legal text, please visit:
 *
 * http://creativecommons.org/licenses/by-sa/3.0/
 *
 * Permissions beyond the scope of this license may be available
 * at http://technofovea.com/ .
 */

import java.nio.ByteBuffer;

import java.util.BitSet;

public class Main {
    /**
     * Reads a series of bytes from the given buffer, turning them into a
     * little-endian bit-set. The ByteBuffer's position is advanced appropriately.
     *
     * Thus the three-byte series of  10000001,00001000,00000000 has set flags
     * at positions 0,7, and 11
     * @param bb ByteBuffer to read from
     * @param numbytes Number of bytes to read.
     * @return A new BitSet with the correct areas set/unset
     */
    public static BitSet readBitset(ByteBuffer bb, int numbytes) {
        byte[] barr = new byte[numbytes];

        bb.get(barr);
        BitSet ret = new BitSet(numbytes * 8);

        for (int i_byte = 0; i_byte < barr.length; i_byte++) {
            for (int i = 0; i < 8; i++) {
                int idx = i_byte * 8 + i;
                boolean isSet = (barr[i_byte] & (1 << i)) > 0;
                ret.set(idx, isSet);
            }
        }
        return ret;
    }
}

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