My beautiful code----feel bad code smell (a serial code review later)

boolean fisrt=true;
for(int i=1;i<=FLAG;i++){
????????? if(fisrt&&((int)Math.pow(2, i)&carrier.getFlags())!=0){
????????????? sb.append(flag[i-1]);
????????????? fisrt=false;
????????? }else if(((int)Math.pow(2, i)&carrier.getFlags())!=0&&!fisrt){
????????????? sb.append("? ,?? "+flag[i-1]);
????????? }
? }

?

?

?

a few days later:

??? private? String getFlagString(int flags) {
??????? StringBuilder sb = new StringBuilder();
??????? String separator = "? , ";
??????? for (CarrierFlagType c : CarrierFlagType.values()) {
??????????? if ((CarrierFlagType.getCarrierTypeValue(c) & flags) != 0) {
??????????????? sb.append(c + separator);
??????????? }
??????? }
??????? if (sb.length() > 0)
??????????? sb.delete(sb.length() - separator.length(), sb.length() - 1);
??????? return sb.toString();

??? }