int sLen = s.length();
int goalLen = goal.length();

if(sLen != goalLen) {
  return false;
}

s = s + s;
final char goalFirstChar = goal.charAt(0);

for(int i = 0; i < goalLen; ++i) {

  if(s.charAt(i) == goalFirstChar) {

    int j = 0;

    while(++j < goalLen && s.charAt(i + j) == goal.charAt(j));

    if(j == goalLen) {
      return true;
    }
  }
}

return false;