java 过滤表情符号

/**
 * 过滤表情符号
 * @create by ldw on 2016-10-25
 * @param str
 * @return str(去掉表情符号的字符串)
 * @version 1.0
 * */
public String filter(String str) {
    if (str.trim().isEmpty()) {
        return str;
    }
    String pattern = "[\ud83c\udc00-\ud83c\udfff]|[\ud83d\udc00-\ud83d\udfff]|[\u2600-\u27ff]";
    String reStr = "";
    Pattern emoji = Pattern.compile(pattern);
    Matcher emojiMatcher = emoji.matcher(str);
    str = emojiMatcher.replaceAll(reStr);
    return str;
}