Hint: Java生成的签名的工具类

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SignUtil
{

	public final static String SHA_256 = "SHA-256";
	public final static String SHA_1 = "SHA-1";
	public final static String MD5 = "MD5";

	/**
	 * 对字符串加密,加密算法使用MD5,SHA-1,SHA-256,默认使用SHA-256
	 * @param encName 加密类型
	 * @param strSrc 要加密的字符串
	 */
	public static String encrypt(String encName, Object... strSrc)
	{
		String strDes = null;
		if (strSrc != null)
		{
			try
			{
				if (encName == null || encName.length() == 0)
				{
					encName = SHA_256;
				}
				MessageDigest md = MessageDigest.getInstance(encName);
				for (Object o : strSrc)
				{
					if (o instanceof byte[])
					{
						md.update((byte[]) o);
					}
					else if (o instanceof String)
					{
						md.update(((String) o).getBytes());
					}
					else if (o != null)
					{
						md.update(String.valueOf(o).getBytes());
					}
				}
				byte[] d = md.digest();
				strDes = bytes2Hex(d); // to HexString
			}
			catch (NoSuchAlgorithmException e)
			{
				// e.printStackTrace();
			}
		}
		return strDes;
	}

	/* ------------------------------------------------------- */

	protected static final char[] HEX_DIGITS = "0123456789abcdef".toCharArray();
	protected static final char[] HEX_DIGITS_UPPER = "0123456789ABCDEF".toCharArray();

	private static String _bytes2Hex(byte[] bts, char[] hexDigits)
	{
		char[] o = new char[bts.length + bts.length];
		for (int i = 0, j = 0; i < bts.length; i++)
		{
			byte b = bts[i];
			o[j++] = hexDigits[(b & 0xf0) >> 4];
			o[j++] = hexDigits[b & 0x0f];
		}
		return new String(o);
	}

	public static String bytes2Hex(byte[] bts)
	{
		return _bytes2Hex(bts, HEX_DIGITS);
	}

	public static String bytes2HexUpper(byte[] bts)
	{
		return _bytes2Hex(bts, HEX_DIGITS);
	}

	/* ------------------------------------------------------- */

	public static String genSign_PkReq(String msg)
	{
		return genSign_PkReq(msg.getBytes());
	}

	public static String genSign_PkReq(byte[] data)
	{
		return encrypt(MD5, "SDK", data, "YINGXIONG-2015");
	}

	public static String genSign_PkResp(String msg)
	{
		return genSign_PkResp(msg.getBytes());
	}

	public static String genSign_PkResp(byte[] data)
	{
		return encrypt(MD5, "YINGXIONG-2015", data, "DKS");
	}

	public static String genSign_AuthSign(String msg, String key)
	{
		return encrypt(MD5, "SDK", msg, key);
	}
}