Live Chat Software by Kayako
How To Install Java on Ubuntu with Apt-Get
Posted by Thang Le Toan on 04 September 2016 05:50 AM
As a lot of articles and programs require to have Java installed, this article will guide you through the process of installing and managing different versions of Java.
Installing default JRE/JDK
This is the recommended and easiest option. This will install OpenJDK 6 on Ubuntu 12.04 and earlier and on 12.10+ it will install OpenJDK 7.
Installing Java with
Then, check if Java is not already installed:
If it returns "The program java can be found in the following packages", Java hasn't been installed yet, so execute the following command:
This will install the Java Runtime Environment (JRE). If you instead need the Java Development Kit (JDK), which is usually needed to compile Java applications (for example Apache Ant, Apache Maven, Eclipse and IntelliJ IDEA execute the following command:
That is everything that is needed to install Java.
All other steps are optional and must only be executed when needed.
Installing OpenJDK 7 (optional)
To install OpenJDK 7, execute the following command:
This will install the Java Runtime Environment (JRE). If you instead need the Java Development Kit (JDK), execute the following command:
Installing Oracle JDK (optional)
The Oracle JDK is the official JDK; however, it is no longer provided by Oracle as a default installation for Ubuntu.
You can still install it using apt-get. To install any version, first execute the following commands:
Then, depending on the version you want to install, execute one of the following commands:
Oracle JDK 6
This is an old version but still in use.
Oracle JDK 7
This is the latest stable version.
Oracle JDK 8
This is a developer preview, the general release is scheduled for March 2014. This external article about Java 8 may help you to understand what it's all about.
Managing Java (optional)
When there are multiple Java installations on your Droplet, the Java version to use as default can be chosen. To do this, execute the following command:
It will usually return something like this if you have 2 installations (if you have more, it will of course return more):
You can now choose the number to use as default. This can also be done for the Java compiler (
It is the same selection screen as the previous command and should be used in the same way. This command can be executed for all other commands which have different installations. In Java, this includes but is not limited to:
Setting the "JAVA_HOME" environment variable
To set the
It returns something like:
The path of the installation is for each:
Copy the path from your preferred installation and then edit the file
In this file, add the following line (replacing YOUR_PATH by the just copied path):
That should be enough to set the environment variable. Now reload this file:
Test it by executing:
If it returns the just set path, the environment variable has been set successfully. If it doesn't, please make sure you followed all steps correctly.