Converting a binary number to a list of integers

Question

I need to convert a binary number to a list of the values of the bit possitions that make up that number. I.e. 1 = 1; 3=2,1; 7=1,2,4.
Does anyone know of Java API functions that could accomplish this, I couldn't find any, or a function that can do this?

Answer 1

This reminds me of my programming homework assignments...
There are some very efficient ways to do this - but I can't remember them off the top of my head. I can guarantee they will have been posted several hundred times before. This will work:
class BitMask {
    private byte mask = 1;
    public void printBitFields(int a) {
     System.out.print(a + " =");
     for(i = 0 ; (a & Integer.MAX_VALUE) != 0 ; i++) {
         if((a & mask) == 1)
          System.out.print(" " + ((int) java.lang.Math.pow(2,i)));
         a >>= 1;
     System.out.println();
    public final static void main(String args[]) {
     BitMask bm = new BitMask();
     bm.print(1);
     bm.print(18);
     bm.print(19); // etc...
}