how to send a byte array

I have a byte array that is a Message digest. I don't want to convert it to string and pull back the array on the other end.

Can I send the byte array using output stream. If I do so, does it work in case of a post(if the jsp is invoked by a post).

When you submit a request, whether it be a post or a get, all request params must be strings.

Perhaps a little more info on what and why you are doing this might help.

when I convert the byte array to string, i can access the value on the other end as a string. When I convert that back to byte array using string.getBytes() I am not able to replicate the byte array.

OK, that's a straight-forward Java issue, so I'm going to move this to the Java in General(intermediate) forum. I suggest you post your conversion code so we can figure out what is wrong with it. (Please use the UBB code tags to preserve the formatting).

Without seeing the conversion code first I would have to ask what type of encoding you are using when you do a string.getBytes() - is it the same as the encoding you started with?

When you make strings out of bytes in Java a lot of strange character encoding issues happen behind the scenes. One suggestion to be able not to worry about this would be to Base64 Encode/Decode the data.

Unfortunately, to my knowledge, there's no Base64Encoder/Decoder included in the standard Java API, but if I'm not mistaken there's an implementation included in the JDK (1.4) in the sun.misc packages:

sun.misc.BASE64Encoder
sun.misc.BASE64Decoder

Otherwise there's an implementation on SourceForge:
http://iharder.sourceforge.net/base64/

I begin with encoding with base64 like this:
raw = sha.digest(secureKey.getBytes("UTF-8"));

And then I create a string from 'raw' so that I can send using a post using raw.toString();

on the other end, I do the following:
byte[] actualSignature =(request.getParameter("secureMessage").trim()).getBytes("UTF-8");

I get totally different value from the byte array I started with.

Originally posted by Mattias Arthursson:
When you make strings out of bytes in Java a lot of strange character encoding issues happen behind the scenes. One suggestion to be able not to worry about this would be to Base64 Encode/Decode the data.

Unfortunately, to my knowledge, there's no Base64Encoder/Decoder included in the standard Java API, but if I'm not mistaken there's an implementation included in the JDK (1.4) in the sun.misc packages:

sun.misc.BASE64Encoder
sun.misc.BASE64Decoder

Otherwise there's an implementation on SourceForge:
http://iharder.sourceforge.net/base64/

I know we can do Base64Encoding. The problem is, it creates a string that is always the same. To propagate across as a security key, if I sent the actual byte array, it looks different for a hacker each time(since for same key the message digest byte array looks different for each invokation)

I know we can do Base64Encoding. The problem is, it creates a string that is always the same.

If Base64 encoding creates a string that is "always the same" then you MUST be starting with the same input every time.
Converting to and from strings with getBytes, etc is always going to be a disaster with random binary data because String conversion involve some assumptions about encoding. The sequence of envents:

byte[] -> base64encode -> (a string in ASCII chars) -> base64decode -> byte[]
is safe with respect to the string being transmitted, read, etc.
Bill