I installed Android Studio but it was giving me error that I need to install JDK but JDK was already installed. Then I realized it is asking to install 64bit version of JDK.
I add a similar problem on Linux. In my case my JAVA_HOME env was pointing to the JRE HOME instead of the JDK HOME.
On my linux system I had done:
sabayon ~ # eselect java-vm list
Available Java Virtual Machines:
[1] icedtea-bin-8
[2] oracle-jdk-bin-1.8
[3] oracle-jre-bin-1.8 system-vm
sabayon ~ # eselect java-vm set system 2
And then Android Studio started like a charm. Download and install the SDK.