微信支付验证或签名失败的原因剖析及三种解决途径

set java_OPTS=-Xms128m -Xmx512m -XX:MaxPermSize=256m -Dfile.encoding=utf-8 -Dsun.jnu.encoding=utf-8

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" };

}