Quick guide to download and install OpenJDK 9 on Ubuntu. - OpenJDK Community Version
OpenJDK is the short form of Open Java Development Kit similar to Oracle's Java Development Kit used to develop Java Applications. Main difference between Oracle JDK and OpenJDK is that OpenJDK is free for all while Oracle Java Development Kit or Oracle JDK requires commercial license. For more details refer openjdk vs oracle jdk
If you want to know more about OpenJDK, you can go through Open Java Development Kit Quick guide.
Note: To uninstall previously installed OpenJDK please refer Uninstall openJDK ubuntu
Open jdk 9 download:
Go to https://jdk.java.net/archive/ and download the OpenJDK 9 tar distribution jdk-9+181_linux-x64_ri.zip. Here is the quick lik to download the OpenJDK 9 tar file jdk-9+181_linux-x64_ri.zip
Ubuntu Java 9 Install - To Install OpenJDK 9 Java Runtime, Enter the below command on Ubuntu command line.
$ sudo apt-get install openjdk-9-jre
$ sudo apt-get install openjdk-9-jdk
Once the above steps are successfully completed , we need to set the "JAVA_HOME" and "PATH" environment variables. Enter the following commands to set your environment variables. Make sure that your environment variables point to a valid installation of JDK on your Ubuntumachine.
Once the OpenJDK 9 Download and installation is complete, we can verify the installed OpenJDK 9 version using below Command.
Go to Ubuntu prompt and type java -version
The above command prints the OpenJDK 9 version you installed.
$ java --version openjdk 9 OpenJDK Runtime Environment (build 9-ea+18-Ubuntu-1) OpenJDK 64-Bit Server VM (build 9ea+18-Ubuntu-1, mixed mode, sharing)
Note: Here is the list of OpenJDK known-issues OpenJDK Known Issues
Here are the ubuntu openjdk packages you might be interested in!
Ubuntu package openjdk-8-jdk
Ubuntu package openjdk-9-jdk
Ubuntu package openjdk-11-jdk
Ubuntu package openjdk-13-jdk
Ubuntu package openjdk-14-jdk
Ubuntu package openjdk-15-jdk
If you are looking out for earlier OpenJDK versions, go to OpenJDK Archive