Java比较有用的进制转换API函数

/**
     * 十六进制字符串装十进制
     * 
     * @param hex
     *            十六进制字符串
     * @return 十进制数值
     */
    public static int hexStringToAlgorism(String hex) {
        hex = hex.toUpperCase();
        int max = hex.length();
        int result = 0;
        for (int i = max; i > 0; i--) {
            char c = hex.charAt(i - 1);
            int algorism = 0;
            if (c >= '0' && c <= '9') {
                algorism = c - '0';
            } else {
                algorism = c - 55;
            }
            result += Math.pow(16, max - i) * algorism;
        }
        return result;
    }

/**
     * 十六进制转字符串
     * 
     * @param hexString
     *            十六进制字符串
     * @param encodeType
     *            编码类型4：Unicode，2：普通编码
     * @return 字符串
     */
    public static String hexStringToString(String hexString, int encodeType) {
        String result = "";
        int max = hexString.length() / encodeType;
        for (int i = 0; i < max; i++) {
            char c = (char) ZhcvActivity.hexStringToAlgorism(hexString
                    .substring(i * encodeType, (i + 1) * encodeType));
            result += c;
        }
        return result;
    }