converting an array of bytes into a (usable) string

[carpeliam]

I have an array of bytes, and I want to convert this into a string containing just the characters A-Z, a-z, and 0-9. I'm wondering what the recommended way to do this might be. I'm sure there are many ways to do it, But I'm looking for the best possible way, and I also don't want to reinvent the wheel.

I'm using jdk1.4, if that makes a difference. Thanks Liam Morley
lmorley@gdc.wpi.edu
"light the deep, and bring silence to the world.
light the world, and bring depth to the silence."

 

[daniel135]

String has a handy constructor just for that:
String(byte[] bytes)
Constructs a new String by decoding the specified array of bytes using the platform's default charset.

For future reference:

http://java.sun.com/j2se/1.4/docs/api/index.html

 

[carpeliam]

thank you for your reply. the problem with that is, certain characters (like "/&quot are within the default charset which I can't handle.

Eventually, this string will wind up within a URL in the form

myurl.com/page.html?var=ABCabc123

, which is why I need to restrict the charset.

I've come up with a few ideas.[ol][li]there are 62 (26 x 2 + 10) characters that fall within my character set. convert the char value of each byte into a number between 1 and 62, and use that as the index for an array (where the array[0] = 'A', array[26] = 'a', array[52] = '0', etc).[/li][li]Construct a new java.nio.charset.Charset. This would only work within 1.4, So I'm not terribly excited about doing that from a portability standpoint (As this is open-source code which will be run/compiled by others). I like it simply because it makes sense to use the String(byte[] bytes, String charsetName) constructor approach.[/li][li]either disregard or generate new values for offending bytes. Disregarding is bad (who knows, I might get an empty string back), and who knows how long it might take to generate new values.[/li][/ol]I'm not a huge fan of any of these plans.. If it wasn't deprecated, I'd use something like String(byte[] ascii, int hibyte).

I'm getting the bytes from SecureRandom. Is there any way to limit the output on that? Or is there a better way of generating a random string of numbers and letters?

Thanks again for your time. Liam Morley
lmorley@gdc.wpi.edu
"light the deep, and bring silence to the world.
light the world, and bring depth to the silence."

 

[carpeliam]

I came up with a solution. I remembered that servlet container session id's have much the same charset.. so I did a little research on how they are constructed. In case you're curious, it seems to be as follows:

java.net.URLEncoder.encode(new java.rmi.server.UID().toString())

thanks in any case. Liam Morley
lmorley@gdc.wpi.edu
"light the deep, and bring silence to the world.
light the world, and bring depth to the silence."