Installation and Configuration of JAVA Development Kit (JDK)
Just in case you install Android Studio and its SDK Tools separately, you need to setup JDK as shown below:
Installation and Configuration of JAVA Development Kit (JDK)
Download java on the following link:
http://www.oracle.com/technetwork/java/javase/downloads/index.html
The above link will download all your necessary JAVA files. It will show all the ways to download and configure the JAVA setup.