problem with utf-8 encoding

i deploying application on tomcat server and i use to download file servlet wich calling procedure is

its working fine but, its not returning correct file name when i have non latin alphabet
but when i adding this "response.setCharacterEncoding("UTF-8");"
i getting error "Exception Details: java.nio.charset.MalformedInputException
Input length = 1"
anybody can help me? why i getting error when i adding encodding utf-8?

Can you please UseCodeTags next time? It makes your code so much easier to read.

This isn't the fix to your problem, but you have a bug in your file reading code:

Irakli Bliadze wrote:

That check should be > -1 instead of > 0. 0 is a valid return value of InputStream.read, it just means there's no data available right now. There is only one value that indicates there is no more data and that's -1.

thanks for advice about codeTag i didn't knew it.
and put >-1 instead of >0 but result is same error