package cn.cnnic.ops.udf;public class GetChineseFromPunycode {    static int TMIN = 1;    static int TMAX = 26;    static int BASE = 36;    static int INITIAL_N = 128;    static int INITIAL_BIAS = 72;    static int DAMP = 700;    static int SKEW = 38;    static char DELIMITER = '-';    static String PUNY_PREFIX = "xn--";    static char DOT = '.';    static String SPLIT_DOT = "\\.";    public static void main(String[] args) {        String str = "xn--fiq7iz9az60bsyah94knxag3d.xn--fiqs8s";        GetChineseFromPunycode gpfc = new GetChineseFromPunycode();        System.out.println(gpfc.evaluate(str));    }    public String evaluate(String txt) {        String strResult = txt.toString().trim();        try {            strResult = fromPunycodeToChinese(txt.toString().trim());        } catch (Exception e) {            e.printStackTrace();        }        return strResult;    }    /**     *      * @param input     * @return     * @throws Exception     */    public static String fromPunycodeToChineseUnit(String input) throws Exception {        int n = INITIAL_N;        int i = 0;        int bias = INITIAL_BIAS;        StringBuilder output = new StringBuilder();        int d = input.lastIndexOf(DELIMITER);        if (d > 0) {            for (int j = 0; j < d; j++) {                char c = input.charAt(j);                if (!isBasic(c)) {                    throw new Exception("BAD_INPUT");                }                output.append(c);            }            d++;        } else {            d = 0;        }        while (d < input.length()) {            int oldi = i;            int w = 1;            for (int k = BASE;; k += BASE) {                if (d == input.length()) {                    throw new Exception("BAD_INPUT");                }                int c = input.charAt(d++);                int digit = codepoint2digit(c);                if (digit > (Integer.MAX_VALUE - i) / w) {                    throw new Exception("OVERFLOW");                }                i = i + digit * w;                int t;                if (k <= bias) {                    t = TMIN;                } else if (k >= bias + TMAX) {                    t = TMAX;                } else {                    t = k - bias;                }                if (digit < t) {                    break;                }                w = w * (BASE - t);            }            bias = adapt(i - oldi, output.length() + 1, oldi == 0);            if (i / (output.length() + 1) > Integer.MAX_VALUE - n) {                throw new Exception("OVERFLOW");            }            n = n + i / (output.length() + 1);            i = i % (output.length() + 1);            output.insert(i, (char) n);            i++;        }        return output.toString();    }    /**     *      * @param delta     * @param numpoints     * @param first     * @return     */    public static int adapt(int delta, int numpoints, boolean first) {        if (first) {            delta = delta / DAMP;        } else {            delta = delta / 2;        }        delta = delta + (delta / numpoints);        int k = 0;        while (delta > ((BASE - TMIN) * TMAX) / 2) {            delta = delta / (BASE - TMIN);            k = k + BASE;        }        return k + ((BASE - TMIN + 1) * delta) / (delta + SKEW);    }    /**     *      * @param c     * @return     */    public static boolean isBasic(char c) {        return c < 0x80;    }    /**     *      * @param d     * @return     * @throws Exception     */    public static int digit2codepoint(int d) throws Exception {        if (d < 26) {            // 0..25 : 'a'..'z'            return d + 'a';        } else if (d < 36) {            // 26..35 : '0'..'9';            return d - 26 + '0';        } else {            throw new Exception("BAD_INPUT");        }    }    /**     *      * @param c     * @return     * @throws Exception     */    public static int codepoint2digit(int c) throws Exception {        if (c - '0' < 10) {            // '0'..'9' : 26..35            return c - '0' + 26;        } else if (c - 'a' < 26) {            // 'a'..'z' : 0..25            return c - 'a';        } else {            throw new Exception("BAD_INPUT");        }    }    /**     *      * @param input     * @return     * @throws Exception     */    public static String fromPunycodeToChinese(String input) throws Exception {        if (input == null || input.equalsIgnoreCase("")) {            return "";        } else if (input.indexOf(DOT) < 0) {            if (input.startsWith(PUNY_PREFIX)) {                return fromPunycodeToChineseUnit(input.substring(PUNY_PREFIX.length()));            } else {                return input;            }        } else if (input.indexOf(DOT) > 0) {            String[] arr = input.split(SPLIT_DOT);            String result = "";            for (int index = 0; index < arr.length; index++) {                if (arr[index].startsWith(PUNY_PREFIX)) {                    result += fromPunycodeToChineseUnit(arr[index].substring(PUNY_PREFIX.length())) + ".";                } else {                    result += arr[index] + ".";                }            }            return result.substring(0, result.length() - 1);        }        return input;    }}

 

【参考】http://blog.csdn.net/a19881029/article/details/18262671