If I have an integer that I'd like to perform bit manipulation on, how can I load it into a java.util.BitSet
? How can I convert it back to an int or long? I'm not so concerned about the size of the BitSet
-- it will always be 32 or 64 bits long. I'd just like to use the set()
, clear()
, nextSetBit()
, and nextClearBit()
methods rather than bitwise operators, but I can't find an easy way to initialize a bit set with a numeric type.
The following code creates a bit set from a long value and vice versa:
public class Bits {
public static BitSet convert(long value) {
BitSet bits = new BitSet();
int index = 0;
while (value != 0L) {
if (value % 2L != 0) {
bits.set(index);
}
++index;
value = value >>> 1;
}
return bits;
}
public static long convert(BitSet bits) {
long value = 0L;
for (int i = 0; i < bits.length(); ++i) {
value += bits.get(i) ? (1L << i) : 0L;
}
return value;
}
}
EDITED: Now both directions, @leftbrain: of cause, you are right