[exim] transport filter with know charset encoding

Hi,

is there anychance, that a transportfilter gets knowlage about the
messages charset before it is processed ?

Background:

java needs to know the charset in which data is delivered via stdin
before it opens stdin.
usually it checks the system $LANG, which indicates UTF8.

But, if you write a filter in java and our message is encoded in
iso-8859-1, but your system charset is utf8,
the message has garbled umlauts ( all non ascii chars like üöäß etc. ).

BUT.. if the program knows the mail charset ahead of opening stdin, it
can set the correct encoding and it works.

I am afraid, that it's now exims job to know the message encoding, right
? :(

hmm.. pdf talks about $mime_charset and content-type... but thats seems
not to be set for the entire message..

(Maybe someone know the problem and has dealt with it in java already)

Marius