public BitField(int mask) 
{
        _mask = mask;
        int count       = 0;
        int bit_pattern = mask;
        if (bit_pattern != 0)
        {
            while ((bit_pattern & 1) == 0)
            {
                count++;
                bit_pattern  > >= 1;
            }
        }
        _shift_count = count;
}

Create a BitField instance

Parameters:

mask - the mask specifying which bits apply to this BitField. Bits that are set in this mask are the bits that this BitField operates on

 public int clear(int holder) 
{
        return holder & ~_mask;
}

Clear the bits.

 public byte clearByte(byte holder) 
{
        return ( byte ) clear(holder);
}

Clear the bits.

 public short clearShort(short holder) 
{
        return ( short ) clear(holder);
}

Clear the bits.

 public int getRawValue(int holder) 
{
        return (holder & _mask);
}

Obtain the value for the specified BitField, unshifted

 public short getShortRawValue(short holder) 
{
        return ( short ) getRawValue(holder);
}

Obtain the value for the specified BitField, unshifted

 public short getShortValue(short holder) 
{
        return ( short ) getValue(holder);
}

Obtain the value for the specified BitField, appropriately shifted right, as a short. Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits)

 public int getValue(int holder) 
{
        return getRawValue(holder)  > > _shift_count;
}

Obtain the value for the specified BitField, appropriately shifted right. Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits)

 public boolean isAllSet(int holder) 
{
        return (holder & _mask) == _mask;
}

Are all of the bits set or not? This is a stricter test than isSet, in that all of the bits in a multi-bit set must be set for this method to return true

 public boolean isSet(int holder) 
{
        return (holder & _mask) != 0;
}

Is the field set or not? This is most commonly used for a single-bit field, which is often used to represent a boolean value; the results of using it for a multi-bit field is to determine whether *any* of its bits are set

 public int set(int holder) 
{
        return holder | _mask;
}

Set the bits.

 public int setBoolean(int holder,
    boolean flag) 
{
        return flag ? set(holder)
                    : clear(holder);
}

Set a boolean BitField

 public byte setByte(byte holder) 
{
        return ( byte ) set(holder);
}

Set the bits.

 public byte setByteBoolean(byte holder,
    boolean flag) 
{
        return flag ? setByte(holder)
                    : clearByte(holder);
}

Set a boolean BitField

 public short setShort(short holder) 
{
        return ( short ) set(holder);
}

Set the bits.

 public short setShortBoolean(short holder,
    boolean flag) 
{
        return flag ? setShort(holder)
                    : clearShort(holder);
}

Set a boolean BitField

 public short setShortValue(short holder,
    short value) 
{
        return ( short ) setValue(holder, value);
}

Replace the bits with new values.

 public int setValue(int holder,
    int value) 
{
        return (holder & ~_mask) | ((value < <  _shift_count) & _mask);
}

Replace the bits with new values.