compression

I am developing an android application which requires to decompress an AES-256 encrypted zip files, is there any libraries out there that I can use to accomplish that? I am greatly appreciative of any guidance or help. zip4j , java library to handle Zip files (Open source, Apache License v2.0). http://www.lingala.net/zip4j/ Create, Add, Extract, Update, Remove files from a Zip file Read/Write password protected Zip files Supports AES 128/256 Encryption Supports Standard Zip Encryption You can download binary, sources and examples. I ended up using an external library at http://code.google.com

I'm writing some scripts that are using the HTML 5 file API in FireFox 3.6. I got some deflated (compressed) files, and I need to inflate (uncompress) them. I found a few scripts while googling, but none of them have tests. So I'm a bit reluctant to use them. My question is: Browsers can inflate. Can I somehow piggyback on the inflation by forging A XHR request? Or piggyback in any other way? Keep in mind, the script is currently FireFox 3.6 exclusive. It can't be an extension, though, I want it to be a regular webpage. Alternatively , are there any scripts that you know of that has tests

I'm creating Python software that compresses files/folders... How would I create a section of the code that asks for the user input of the folder location and then compresses it. I currently have the code for a single file but not a folder full of files. Please explain in detail how to do this. The code to compress a folder in to tar file is: import tarfile tar = tarfile.open("TarName.tar.gz", "w:gz") tar.add("folder/location", arcname="TarName") tar.close() It works for me. Hope that works for you too. GZip doesn't do compression of folders/directories, only single files. Use the zipfile

I was wondering whether SVN actually compresses the binary content on the server during Commits? I know that the binary store the diffgrams for comparison and versioning but wondered whether a new file commited would occupy the same volume on the server as it does on the client pc? I believe so. From here: http://svn.apache.org/repos/asf/subversion/trunk/INSTALL * libz (REQUIRED for client and server) Subversion uses zlib for compressing binary differences. These diff streams are used everywhere -- over the network, in the repository, and in the client's working copy. Yes, Subversion

It's well known that GZIP or DEFLATE (or any compression mechanism) can increase file size sometimes. Is there a maximum (either percentage or constant) that a file can be increased? What is it? If a file is X bytes, and I'm going to gzip it, and I need to budget for file space in advance - what's the worst case scenario? UPDATE: There are two overheads: GZIP adds a header, typically 18 bytes but essentially arbitrarily long. What about DEFLATE? That can expand content by a multiplicative factor, which I don't know. Does anyone know what it is? gzip will add a header and trailer of at least 18

I am using the following code to extract a zip file in Java. import java.io.*; import java.util.zip.*; class testZipFiles { public static void main(String[] args) { try { String filename = "C:\\zip\\includes.zip"; testZipFiles list = new testZipFiles( ); list.getZipFiles(filename); } catch (Exception e) { e.printStackTrace(); } } public void getZipFiles(String filename) { try { String destinationname = "c:\\zip\\"; byte[] buf = new byte[1024]; ZipInputStream zipinputstream = null; ZipEntry zipentry; zipinputstream = new ZipInputStream( new FileInputStream(filename)); zipentry = zipinputstream