String manipulation of a http response using Arduino
I had a look at the documentation, and it seems that you get the HTTP response from the Ethernet library, but you need to extract the information by other means.

I see two possibilities: (a) you parse the answer using C/C++ standard functions, or (b) you use a library created by somebody else. I found two libraries that may help you: this and this. Have a look at them and tell us how it goes with them.