Blackberry - Programmatically extract/open zip file

Question

I have looked online with mixed results, but is there a way to programmatically extract a zip file on the BB? Very basic my app will display different encrypted file types, and those files are delivered in a zip file. My idea was to have the user browse to the file on their SDCard, select it, and I extract what i need as a stream from the file. is this possible?

Answer 1

Use GZIPInputStream

Example:

 try
 {
  InputStream inputStream = httpConnection.openInputStream();
  GZIPInputStream gzis = new GZIPInputStream(inputStream);
  StringBuffer sb = new StringBuffer();

  char c;
  while ((c = (char)gzis.read()) != -1)
  {
   sb.append(c);
  }

  String data = sb.toString();

  gzis.close();
 }
 catch(IOException ioe)
 {
 }

Answer 2

Just two things:

• In BB API there are only GZip and ZLib support, and no multiple files compression support, so it's not possible to compress several files and extract only one of them.
• Up to my experience, such functionality will fly on simulator, but may be really performance-killing on real device

See How to retrieve data from a attached zip file in Blackberry application?

PS Actually you can implement custom multi-entries stream and parse it after decompress, but that seems to be useless, if you want this archive format to be supported in other applications.

Answer 3

Hello, I have a problem like this: I just want to extract a .zip file. Can we use the GZipInputStream to extract it or GZipInputStream is only for .gz file. Any hel would be great!