aaron@Server:~$ sudo apt install openjdk-9-jdk
[sudo] password for aaron: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
openjdk-9-jdk is already the newest version (9~b114-0ubuntu1).
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 openjdk-9-jdk : Depends: openjdk-9-jdk-headless (= 9~b114-0ubuntu1) but it is not going to be installed
                 Recommends: libxt-dev but it is not going to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).
aaron@Server:~$