4206909 - adding Z_SYNC_FLUSH support to deflaters

[Martin Buchholz]

The obvious alternative to built-in zlib
in the jdk is jzlib

http://www.jcraft.com/jzlib/

a pure-java implementation of zlib
under an apparently GPL-compatible license
that does support flush modes.
Some people are using it for that reason.

Non-scientific benchmarks at Google suggest
it is twice as slow as JDK Deflater,
so we may not want to throw out C zlib just yet.

Martin