Python or Java?

Im very new to arduino, so Im a kind of a newbie but i have this project in mind.
My plan is to threw a website (example facebook, twitter) beable to controll my arduino by sending a message (for example !on).
The problem is that i dont have a wifi shield so i did some research and i found that you can use Java or python to read a website and then send information to the Arduino.

So my questions is should i learn Python or Java?

If you don't know either of them Python will probably be easier.

Java programs run on the Java Virtual Machine (JVM) which means they should be portable to any PC that can run the JVM. If, for whatever reason, you need to be able to use the JVM you don't actually have to use Java. I do my PC programming using JRuby which runs on the JVM but doesn't look anything like Java. JRuby and Python are probably equally easy to use. I just prefer the Ruby language.

Just to complete the picture (and sorry for any confusion) there is also Ruby (without the J) which doesn't use the JVM and isn't easily portable between different systems. Most Ruby code will also run on JRuby but JRuby can also use features of the Java system, for example to create desktop GUIs.

Writing a website with JRuby (or Ruby) and an add-on called Sinatra is very simple. You may have heard of Ruby on Rails (which is a very clever concept for web applications). Sinatra is for smaller projects and is easier to get to grips with.

Of course if you already know some other PC language you can probably use that.