Activity restart on rotation Android

In my Android application, when I rotate the device (slide out the keyboard) then my Activity is restarted (onCreate is called). Now, this is probably how it's supposed to be, but I do a lot of initial setting up in the onCreate method, so I need either:

1. Put all the initial setting up in another function so it's not all lost on device rotation or
2. Make it so onCreate is not called again and the layout just adjusts or
3. Limit the app to just portrait so that onCreate is not called.

• There is a rather complete explanation on how to retain long-running asynchronous tasks during activity configuration changes in this blog post too! - Adrian Monk
• This is not a direct answer as others have answered already, but I invite you to have a look at LogLifeCycle to understand what happens in your android apps regarding to life cycles. - Snicolas
• This is what happens when android screen rotates. - Ajit Singh