Half-baked BitSet using byte[] rather than long[]

gistfile1.java

package com.mozilla.telemetry;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;


/**
 * Half-baked bitset using ints rather than longs
 */
public class PseudoBitSet {

    private byte[] bytes;
    
    public PseudoBitSet(int numBits) {
        bytes = new byte[(int)Math.ceil((double)numBits / 8.0d)];
        System.out.println("words.length: " + bytes.length);
    }
    
    public void setBit(int bitIndex) {
        System.out.println("Bit index: " + bitIndex);
        if (bitIndex < 0) {
            throw new IllegalArgumentException("Invalid bit index");
        }
        
        int byteIdx = (int)Math.floor((double)bitIndex / 8.0d);
        if (byteIdx > bytes.length) {
            throw new IllegalArgumentException("Bit index overflow");
        }
        
        System.out.println("Using byte index: " + byteIdx);
        int bitIdx = bitIndex - (byteIdx * 8);
        System.out.println("Using modified bit index: " + bitIdx);
        bytes[byteIdx] |= (1 << bitIdx);
    }
    
    public byte[] toBytes() {
        return bytes;
    }
    
    public byte[] toLittleEndianBytes() {
        ByteBuffer buf = ByteBuffer.allocate(bytes.length);
        buf.put(bytes);
        return buf.order(ByteOrder.LITTLE_ENDIAN).array();
    }
    
    public String toLittleEndianBinaryString() {
        StringBuilder sb = new StringBuilder();
        for (byte b : this.toLittleEndianBytes()) {
            sb.append(byteToLittleEndianBinaryString(b)).append(" ");
        }
        
        return sb.toString();
    }
    
    public static String byteToLittleEndianBinaryString(byte n) {
        StringBuilder sb = new StringBuilder("00000000");
        for (int bit = 7; bit >= 0; bit--) {
            if (((n >> bit) & 1) > 0) {
                sb.setCharAt(bit, '1');
            }
        }
        return sb.toString();
    }
    
    public static void main(String[] args) {
        PseudoBitSet pbs = new PseudoBitSet(16);
        pbs.setBit(0);
        pbs.setBit(6);
        pbs.setBit(11);
        System.out.println("Little Endian Bit String Representation: " + pbs.toLittleEndianBinaryString());
    }
    
}