Hi,

Do you know of an 'incremental' archive format that would be suited for an  
outputstream?

In other words, is there any archive format that can hold open the existing
entries and allow to append them in an interlaced fashion? (an
incrementally updating archive?)

Let me explain.

Let's say I have 2 types (A nd B) of csv data to send.
A1.csv, A2.csv, A3.csv
B1.csv, B2.csv, B3.csv

I want to write to a stream an archive format that will contain 2 entries
(A and B) where A is the contatenation of A1+A2+A3, and B is the
contatenation of B1+B2+B3.

Now, imagine a zip file. It is easy enough to create a new zip entry A, and
push all A1, A2, A3 files in sequence, and create a second zip entry B and
push B1, B2, B3.

But here is the problem: the sequence is rolling (like a log4j file-size-
rolling appender) and by the time I finished pushing A3, B1 be have rolled
off. I want to push A1 B1, A2 B2, A3 B3.

So, I cannot use java's zipfile, at least not that I know of, to "append
existing entry" instead of putNextEntry().

Something smart like gzip (where you can concatenate independant gzip files
and they become a valid single gzip file) only for multiple entries (that
gzip doesn't have) would be great!

Thanks.