如何判别字段中是否包含了emojicon表情以及过滤相关内容

<span style="font-family: Arial, Helvetica, sans-serif;">过滤该表情</span>

public static String filterEmoji(String source) {
  if (!containsEmoji(source)) {
   return source;// 如果不包含，直接返回
  }
  
  StringBuilder buf = null;
  int len = source.length();
  for (int i = 0; i < len; i++) {
   char codePoint = source.charAt(i);
   if (!isEmojiCharacter(codePoint)) {
    if (buf == null) {
     buf = new StringBuilder(source.length());
    }
    buf.append(codePoint);
   } else {
   }
  }
  if (buf == null) {
   return "";
  } else {
   if (buf.length() == len) {// 这里的意义在于尽可能少的toString，因为会重新生成字符串
    buf = null;
    return source;
   } else {
    return buf.toString();
   }
  }
 }
 

// 判别是否包含Emoji表情
 private static boolean containsEmoji(String str) {
  int len = str.length();
  for (int i = 0; i < len; i++) {
   if (isEmojiCharacter(str.charAt(i))) {
    return true;
   }
  }
  return false;
 }
 
 private static boolean isEmojiCharacter(char codePoint) {
        return !((codePoint == 0x0) ||
                (codePoint == 0x9) ||
                (codePoint == 0xA) ||
                (codePoint == 0xD) ||
                ((codePoint >= 0x20) && (codePoint <= 0xD7FF)) ||
                ((codePoint >= 0xE000) && (codePoint <= 0xFFFD)) ||
                ((codePoint >= 0x10000) && (codePoint <= 0x10FFFF)));
    }