package com.net.util;import java.security.MessageDigest;/** * MD5签名工具类 * @author zhangdi * */public class MD5Util {    private static String byteArrayToHexString(byte b[]) {        StringBuffer resultSb = new StringBuffer();        for (int i = 0; i < b.length; i++)            resultSb.append(byteToHexString(b[i]));        return resultSb.toString();    }    private static String byteToHexString(byte b) {        int n = b;        if (n < 0)            n += 256;        int d1 = n / 16;        int d2 = n % 16;        return hexDigits[d1] + hexDigits[d2];    }    public static String MD5Encode(String origin, String charsetname) {        String resultString = null;        try {            resultString = new String(origin);            MessageDigest md = MessageDigest.getInstance("MD5");            if (charsetname == null || "".equals(charsetname))                resultString = byteArrayToHexString(md.digest(resultString                        .getBytes()));            else                resultString = byteArrayToHexString(md.digest(resultString                        .getBytes(charsetname)));        } catch (Exception exception) {        }        return resultString;    }    private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5",            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };}