16进制转ascii，转字符串

    /**
     * 16进制转化为字母
     * @param hex  要转化的16进制数，用逗号隔开
     *         如：53,68,61,64,6f,77
     * @return
     */
    public static String hex2Str(String hex) {
        StringBuilder sb = new StringBuilder();
        String[] split = hex.split(",");
        for (String str : split) {
            int i = Integer.parseInt(str, 16);
            sb.append((char)i);
        }
        return sb.toString();
    }

/**
     * 字符串中每个字母转化为16进制
     * @param letter
     * @return
     */
    public static String str2Hex(String letter) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < letter.length(); i++) {
            char c = letter.charAt(i);
            sb.append(Integer.toHexString(c));
            sb.append(", ");
        }
        sb.deleteCharAt(sb.length() - 2);
        return sb.toString();
    }