code: public static double similar(String strA, String strB) {
  		String newStrA, newStrB;
  		if (strA.length() < strB.length()) {
  			newStrA = removeSign(strB);
  			newStrB = removeSign(strA);
  		} else {
  			newStrA = removeSign(strA);
  			newStrB = removeSign(strB);
  		}
  		// 用较大的字符串长度作为分母，相似子串作为分子计算出字串相似度
  		int temp = Math.max(newStrA.length(), newStrB.length());
  		int temp2 = longestCommonSubstring(newStrA, newStrB).length();
  		return NumberUtil.div(temp2, temp);
  	}
docs: 计算相似度
  
  @param strA 字符串1
  @param strB 字符串2
  @return 相似度