Use Apt-get to install ORACLE-JDK on Ubuntu

2. Installing default JRE/JDK

   sudo apt-get update
   sudo apt-get install Default-jre
   sudo apt-get install DEFAULT-JDK

4. Installing Oracle JDK

   sudo apt-get install python-software-properties
   sudo add-apt-repository Ppa:webupd8team/java
   sudo apt-get update

   Oracle JDK 6 (older version)
   sudo apt-get install Oracle-java6-installer
   Oracle JDK 7 (newer stable version)
   sudo apt-get install Oracle-java7-installer
   Oracle JDK 8 (latest preview version)
   sudo apt-get install Oracle-java8-installer

6. Managing Java

   sudo update-alternatives--config Java has 2 candidates that can be used to replace Java (providing/usr/bin/java).

   Select Path Priority state

   * 0/usr/lib/jvm/java-7-oracle/jre/bin/java 1072 Auto mode
   1/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java 1071 Manual Mode
   2/usr/lib/jvm/java-7-oracle/jre/bin/java 1072 Manual Mode
   To maintain the current value [*], press ENTER, or type the number you selected:
   (I pressed the carriage return, did not change)
   sudo update-alternatives--config javac
   Ibid.

8. Setting the "java_home" environment variable This command allows you to see the JAVA installation path:

   sudo update-alternatives--config Java determines the path according to the option set, I am using the default first, so path is:

   "/usr/lib/jvm/java-7-oracle"
   sudo vim/etc/environment
   At the end of the file add:

   Java_home= "/usr/lib/jvm/java-7-oracle"

Save exit (: Wq), enter in Terminal:

source /etc/environment

Then enter:
Echo $JAVA _home
If the output is the same as our setup, it means that we have successfully installed it, and then you can look at the Java version:

java -version

Use Apt-get to install ORACLE-JDK on Ubuntu