...
You will also need a Java 8 installation on your machine and have your JAVA_HOME and PATH point to the new installation. Java 8 can be downloaded and installed from the Oracle website.
For e.g., I have the following on my Mac machine's .bash_profile:
...
On Windows the environment variables have to be set up differently, refer to this stackoverflow question to see how it can be done.
...
A free version of IntelliJ (Community Edition) can be downloaded and installed from the Jetbrains website.
Step 4: Your first project