/*
     * 中文轉unicode編碼
     */
    public static String gbEncoding(final String gbString) {
        char[] utfBytes = gbString.toCharArray();
        String unicodeBytes = "";
        for (int i = 0; i < utfBytes.length; i++) {
            String hexB = Integer.toHexString(utfBytes[i]);
            
 
if (hexB.length() <= 2) {
                hexB = "00" + hexB;
            }
            unicodeBytes = unicodeBytes + "\\u" + hexB;
        }
        return unicodeBytes;
    }
    /*
     * unicode編碼轉中文
     */
    public static String decodeUnicode(final String dataStr) {
        int start = 0;
        
 
int end = 0;
        final StringBuffer buffer = new StringBuffer();
        while (start > -1) {
            end = dataStr.indexOf("\\u", start + 2);
            String charStr = "";
            if (end == -1) {
                charStr = dataStr.substring(start + 2, dataStr.length());
            } 
 
else {
                charStr = dataStr.substring(start + 2, end);
            }
            char letter = (char) Integer.parseInt(charStr, 16); // 16進位制parse整形字串。
            buffer.append(new Character(letter).toString());
            start = end;
        }
        return buffer.toString();
    }

原文連結：https://www.cnblogs.com/boluoboluo/p/6504641.html