Installing android studio is a pain in the Ass, and installing it dependencies is a level up to that. The most complex among those is the JDK one.
Below are the steps to achieve so.
# install (open) jdk 8
sudo apt-get install -y openjdk-8-jdk
# update java compiler and set to 1.8
sudo update-alternatives --config javac
# update java runtime (optional)
sudo update-alternatives --config java
# Also set $JAVA_HOME and $PATH to your .bashrc (optional)
echo 'export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64' >> ~/.bashrc echo 'export PATH="$PATH:$JAVA_HOME/bin' >> ~/.bashrc
# load in current bash session