My Java application is currently using ZIP as a project file format. The project files contain a few XML files and many image and sound files.
The project files are getting pretty big, and since I can’t find a way with the java.util.zip classes to write to a ZIP file without recreating it, my file saves are becoming very slow. So for example, if I just want to update one XML file, I need to rewrite the entire ZIP.
Is there some other Java ZIP library that will allow me to do random writes to a ZIP file?
I know switching to something like SQLite solves the random write issue. Would using SQLite just to write XML, Sound and Images as blobs be an appropriate use?
I suppose I could come up with my own file format and use RandomAccessFile but then there would be a lot of bookkeeping I’d have to write.
Update…
My file format is very much like Office Open XML. It is a ZIP file containing XML and other resources.
Someone must have solved the problem of how to do random writes to update a ZIP file. Does anyone know how?
There exist so-called single-file virtual file systems, that let you create file-based containers and provide file-system like structure and APIs. One of the samples is SolFS (it has C-written core with JNI wrapper) and some other C- and Delphi-written solutions (I don’t remember their names at the moment). I guess there exist similar native Java solutions as well.