code: private List<String> splitSimhash(Long simhash) {
  		final int bitNum = this.bitNum;
  		final int fracBitNum = this.fracBitNum;
  
  		final List<String> ls = new ArrayList<String>();
  		final StringBuilder sb = new StringBuilder();
  		for (int i = 0; i < bitNum; i++) {
  			sb.append(simhash >> i & 1);
  			if ((i + 1) % fracBitNum == 0) {
  				ls.add(sb.toString());
  				sb.setLength(0);
  			}
  		}
  		return ls;
  	}
docs: 将simhash分成n段
  
  @param simhash Simhash值
  @return N段Simhash