try {
     //編碼
    String encodeStr = URLDecoder.decode("字符串", StandardCharsets.UTF_8.name());
    //解碼
    String decodeStr = URLDecoder.decode(encodeStr, StandardCharsets.UTF_8.name());
} catch (UnsupportedEncodingException e) {
    e.printStackTrace();
}

public class EmojiUtils {

    /**
     * 對(duì)emoji表情單獨(dú)編碼
     */
    public static String escape(String src){
        //1.得到代碼點(diǎn)數(shù)量，也即是實(shí)際字符數(shù)，注意和length()的區(qū)別
        //舉例：
        //一個(gè)emoji表情是一個(gè)字符，codePointCount()是1，length()是2。
        //但是遇到過一個(gè)emoji表情居然帶著空格符號(hào)，結(jié)果它的codePointCount()是2，length()也是2，實(shí)際上單獨(dú)拎emoji來說，它的length()應(yīng)該說是1才對(duì)了。
        //推測(cè)這就是它們是否屬于增補(bǔ)字符范圍內(nèi)，length=2的是增補(bǔ)字符，length=1的不是。
        int cpCount = src.codePointCount(0, src.length());

        //2.得到字符串的第一個(gè)代碼點(diǎn)index，和最后一個(gè)代碼點(diǎn)index
        //舉例：比如3個(gè)emoji表情，那么它的cpCount=3；firCodeIndex=0；lstCodeIndex=4
        //因?yàn)槊總€(gè)emoji表情length()是2，所以第一個(gè)是0-1，第二個(gè)是2-3，第三個(gè)是4-5
        int firCodeIndex = src.offsetByCodePoints(0, 0);
        int lstCodeIndex = src.offsetByCodePoints(0, cpCount - 1);

        StringBuilder sb = new StringBuilder();
        int index = firCodeIndex;
        while (index<=lstCodeIndex){
            //3.獲得代碼點(diǎn)，判斷是否是emoji表情
            //注意，codePointAt(int) 這個(gè)int對(duì)應(yīng)的是codeIndex
            //舉例:3個(gè)emoji表情，取第3個(gè)emoji表情，index應(yīng)該是4
            int codepoint = src.codePointAt(index);
            if (!isEmojiCharacter(codepoint)) {
                sb.append((char) codepoint);
            }else{
                try {
                    //4.對(duì)emoji表情UTF-8編碼，判斷是否是增補(bǔ)字符范圍內(nèi)
                    int length = Character.isSupplementaryCodePoint(codepoint)? 2 : 1;
                    String encoderStr = URLEncoder.encode(src.substring(index,index + length), "UTF-8");
                    sb.append(encoderStr);
                } catch (UnsupportedEncodingException e) {

                }
            }
            //4.確定指定字符（Unicode代碼點(diǎn)）是否在增補(bǔ)字符范圍內(nèi)。
            //因?yàn)槌吮砬?，還有些特殊字符也是在增補(bǔ)字符方位內(nèi)的。
            index += Character.isSupplementaryCodePoint(codepoint)? 2 : 1;
        }
        return sb.toString();
    }
    
    /**
     * 過濾掉emoji表情
     * @param src
     * @return
     */
    public static String filter(String src) {
        if (src == null) {
            return null;
        }
        //得到codePointCount
        int cpCount = src.codePointCount(0, src.length());
        int firCodeIndex = src.offsetByCodePoints(0, 0);
        int lstCodeIndex = src.offsetByCodePoints(0, cpCount - 1);
        StringBuilder sb = new StringBuilder(src.length());
        for (int index = firCodeIndex; index <= lstCodeIndex;) {
            //遍歷每個(gè)codePoint
            int codepoint = src.codePointAt(index);
            if (!isEmojiCharacter(codepoint)) {
                System.err.println("codepoint:" + Integer.toHexString(codepoint));
                sb.append((char) codepoint);
            }
            index += ((Character.isSupplementaryCodePoint(codepoint)) ? 2 : 1);

        }
        return sb.toString();
    }


    /**
     * 是否是Emoji表情
     */
    private static boolean isEmojiCharacter(int codePoint) {
        return (codePoint >= 0x2600 && codePoint <= 0x27BF) // 雜項(xiàng)符號(hào)與符號(hào)字體
                || codePoint == 0x303D || codePoint == 0x2049 || codePoint == 0x203C
                || (codePoint >= 0x2000 && codePoint <= 0x200F)//
                || (codePoint >= 0x2028 && codePoint <= 0x202F)//
                || codePoint == 0x205F //
                || (codePoint >= 0x2065 && codePoint <= 0x206F)//
                /* 標(biāo)點(diǎn)符號(hào)占用區(qū)域 */
                || (codePoint >= 0x2100 && codePoint <= 0x214F)// 字母符號(hào)
                || (codePoint >= 0x2300 && codePoint <= 0x23FF)// 各種技術(shù)符號(hào)
                || (codePoint >= 0x2B00 && codePoint <= 0x2BFF)// 箭頭A
                || (codePoint >= 0x2900 && codePoint <= 0x297F)// 箭頭B
                || (codePoint >= 0x3200 && codePoint <= 0x32FF)// 中文符號(hào)
                || (codePoint >= 0xD800 && codePoint <= 0xDFFF)// 高低位替代符保留區(qū)域
                || (codePoint >= 0xE000 && codePoint <= 0xF8FF)// 私有保留區(qū)域
                || (codePoint >= 0xFE00 && codePoint <= 0xFE0F)// 變異選擇器
                || codePoint >= 0x10000; // Plane在第二平面以上的，char都不可以存，全部都轉(zhuǎn)
    }
}