转载至

注意转载原作者的代码是有误的
private static String toMd5(byte[] bytes) {
		try {
			MessageDigest algorithm = MessageDigest.getInstance("MD5");
			algorithm.reset();
			algorithm.update(bytes);
			return toHexString(algorithm.digest(), "");
		} catch (NoSuchAlgorithmException e) {
		  	Log.v("he--------------------------------ji", "toMd5(): " + e);
			throw new RuntimeException(e);
			// 05-20 09:42:13.697: ERROR/hjhjh(256):
			// 5d5c87e61211ab7a4847f7408f48ac
		}
}

private static String toHexString(byte[] bytes, String separator) {
		StringBuilder hexString = new StringBuilder();
		for (byte b : bytes) {
			hexString.append(Integer.toHexString(0xFF & b)).append(separator);
		}
		return hexString.toString();
}


很不幸的是，原作者的md5算法是有误的。在与python作md5对称的时候，发现有时候会少一位(31)，在网上查找到的资料stackoverflow

正确的
private static String toMd5(byte[] bytes) {
		try {
			MessageDigest algorithm = MessageDigest.getInstance("MD5");
			algorithm.reset();
			algorithm.update(bytes);
			return toHexString(algorithm.digest(), "");
		} catch (NoSuchAlgorithmException e) {
		  	Log.v("he--------------------------------ji", "toMd5(): " + e);
			throw new RuntimeException(e);
			// 05-20 09:42:13.697: ERROR/hjhjh(256):
			// 5d5c87e61211ab7a4847f7408f48ac
		}
}
private static String toHexString(byte[] bytes, String separator) {
	StringBuilder hexString = new StringBuilder();
	for (byte b : bytes) {
		String hex = Integer.toHexString(0xFF & b);
		if(hex.length()==1){
			hexString.append('0');
		}
		hexString.append(hex).append(separator);
	}
	return hexString.toString();
}