Does anyone know of a Java implementation of the PPMD compression algorithm?
I have not been able to find a Java implementation, but there is a C# implementation at http://users.senet.com.au/~mjbone/Compression.html that is about 4k lines of code. I'm not going to ask if anyone feels like porting it to Java...
I was using for the same implementation, and couldn't find any. But I found that 7zip gives the source code of their ppmd implementation just in C++, not in java (at least, until now).
I used system call's to 7zip do compress the data I need, using the command-line version of 7zip.
Please see http://www.example-code.com/java/ppmd.asp and libraries to be found in here http://www.chilkatsoft.com/java.asp
If you are looking for very fast compression, you may also try the java implementation of Google Snappy found here: http://code.google.com/p/snappy/
Snappy is used widely within Google.
There seems to be a commercial closed source PPMd implementation here. I have not tried it, nor do I know anything else about it or the company producing it, so I do not know if it is compatible with the 7-zip version of the algorithm. It does not seem to be a pure Java implementation though - it's probably using native calls in the background.