二进制序列有多少个1

public static int count(int n){
		if(n<0 || n>255){
			return -1;
		}
		int count = 0;
		while(n>0){
			int temp = n & 1;
			if(temp == 1){
				count++;
			}
			n = n >>> 1;
		}
		return count;
	}