Dealing with GZIP Content

So .... Long time no see eh?
Oh well there are many reasons for that but truth is "you don't care about that".
Let's jump then into this post topic, which is ZIPED content.

As you may or may not know web servers can send you the content you are requesting in a compress way. Main reason for this is, of course, cause you save bandwidth.
Problem being, you have to deal with that content.
As it turns out you usually come across this when you are creating some sort of HTTP client to consume something and when you try to print the data you can no read it (this is what happened to me).

Easiest way to know for sure that the server is doing this is, checking the following HTTP header:

Content-Encoding: gzip 

This tells you that the "content" has been "gziped", quite obvious rigtht?

Now lets talk about code, how do I deal with this.
Well if you are a smart chap and you are using Jersey Client, this is how:


import com.sun.jersey.api.client.filter.GZIPContentEncodingFilter;

List<ClientFilter> clientFilters = new ArrayList<ClientFilter>();
clientFilters.add(new GZIPContentEncodingFilter(false));

if (clientFilters != null) {
  for (ClientFilter clientFilter : clientFilters) {
      client.addFilter(clientFilter);
  }
}

As you can imagine the client is the Jersey Client, and basically what this code does is to add a filter.
For Jersey filters are plugin of code that in the end knows how to do certain stuff with the payload you send.
In this case this filter "GZIPContentEncodingFilter" knows how to add the HTTP header I showed you before BUT ALSO, it knows how to zip the payload you're seeing.

Now that I've showed you how to handle this with Jersey I've also thought it'll be a good idea to show you just how to decode and encode any content in the same way, and this is how:

Decode: 
InputStream io = (InputStream) someInputStreamYouHad;
String payload = new String(IOUtils.toByteArray(new GZIPInputStream(io)));


Encode:

OutputStream os = new ByteArrayOutputStream();
OutputStream realOs = new GZIPOutputStream(os);
      
realOs.write(payload.getBytes());
realOs.close();
payload = os.toString();

And that's it, hope it helps you/me.