You will be able to install the JDK or the Java version 9 development environment on Linux Ubuntu as well as most distributions derived from Debian, such as Linux Mint. Note that since March 2018, only the 64-bit version of Java 9 can be implemented in Ubuntu.
Step 1. Open a terminal
Open menu ⋮⋮⋮ and expand it, then click on the icon symbolizing the terminal
You also have the option of simultaneously pressing the shortcut keys Alt + Ctrl + T
Step 2. Remove the versions of Java already installed on your system
This is very important, because if you don't, the procedure described here will have no effect:
- type sudo apt-get purge openjdk - \ *;
- press the Enter key;
- if prompted by the system, enter your password;
- press O if prompted, then press Enter on your keyboard.
Step 3. Enter the Java install command
Type sudo apt-get install software-properties-common and press Enter on your keyboard.
Step 4. Remove all versions of Java already installed
Type sudo apt autoremove and press Enter, then wait for your old environment to be completely uninstalled from your system. This will have the double advantage of freeing up space on your hard drive and avoiding any risk of interference during the installation of Java.
The uninstallation process may take several minutes
Step 5. Update the list of packages to install
Type sudo apt-get update and press Enter to ensure that the list of software packages in the Ubuntu repository on your system is fully updated.
Step 6. Navigate to the Oracle software repository
Type sudo add-apt-repository ppa: webupd8team / java in your terminal and press Enter on your keyboard.
Step 7. Press the Enter key again when prompted
When you see the message displayed at the bottom of the terminal window Press [ENTER] to continue or Ctrl-c to cancel adding the repository, press the Enter key on your keyboard.
Step 8. Download the Java installer
Type sudo apt-get install oracle-java9-installer and press Enter. When prompted, type o then press Enter again. The download of the Java 9 installer will begin. At this point, you will see a confirmation dialog in your terminal.
Step 9. Read and accept the software license terms
Press the Enter key once on your keyboard to continue, then use the left arrow key to select Yes and press the Enter key again.
Step 10. Wait for the Java download to finish
Be patient, because the process will take about 20 minutes. Wait for the command prompt in your name to reappear in the terminal to continue.
Step 11. Set Java 9 as the default version
Type sudo apt-get install oracle-java9-set-default and press Enter on your keyboard, then enter your password if prompted.
Step 12. Check the installed version of Java
Type java --version in your terminal and press the Enter key on your keyboard. If everything went as expected, you should see the following text displayed:
java version "9, 0.4"
Step 13. Update your package lists again
Type sudo apt-get update and press Enter. This will have no effect other than ensuring that the Java package lists as well as those of other software that are installed on your PC will remain up to date. The installation of the Java 9 development environment is now complete and you will be able to exit your terminal when the package list update is complete.