Installing Java with apt-get is easy. First, update the package index:
$ sudo apt-get update
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:
$ sudo apt-get install python-software-properties $ sudo add-apt-repository ppa:webupd8team/java $ sudo apt-get updateThen, 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.$ sudo apt-get install oracle-java6-installerOracle JDK 7
This is the latest stable version.$ sudo apt-get install oracle-java7-installerOracle JDK 8
This is a developer preview, the general release is scheduled for March 2014.$ sudo apt-get install oracle-java8-installerManaging Java (optional)
To do this, if there are multiple Java installations execute the following command:
$ sudo update-alternatives --config javaIt will usually return something like this if you have 2 installations (if you havemore, it will of course return more):There are 2 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ------------------------------------------------------------ * 0 /usr/lib/jvm/java-7-oracle/jre/bin/java 1062 auto mode 1 /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java 1061 manual mode 2 /usr/lib/jvm/java-7-oracle/jre/bin/java 1062 manual mode Press enter to keep the current choice[*], or type selection number: You can now choose the number to use as default. This can also be done for the Java compiler (javac):$ sudo update-alternatives --config javacIt 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: keytool, javadoc and jarsigner.
