How to install Oracle Java in Linux

Check to see if your Ubuntu Linux operating system architecture is 32-bit or 64-bit, open up a terminal and run the following command below.
getconf LONG_BIT

It will print the exact number 32 or 64.

Download the Oracle Java JDK/JRE for Linux. Make sure you select the correct compressed binaries for your system architecture 32-bit or 64-bit (which end in tar.gz).
For example, if you are on Ubuntu Linux 32-bit operating system download 32-bit Oracle Java binaries.
For example, if you are on Ubuntu Linux 64-bit operating system download 64-bit Oracle Java binaries.

Important Information: 64-bit Oracle Java binaries do not work on 32-bit Ubuntu Linux operating systems, you will receive multiple system error messages, if you attempt to install 64-bit Oracle Java on 32-bit Ubuntu Linux.

Copy the Oracle Java binaries into the /usr/local/java directory. In most cases, the Oracle Java binaries are downloaded to: /home/"your_user_name"/Downloads.

32-bit Oracle Java on 32-bit Ubuntu Linux installation instructions:
Type/Copy/Paste: cd /home/"your_user_name"/Downloads
Type/Copy/Paste: sudo cp -r jdk-7u40-linux-i586.tar.gz /usr/local/java
Type/Copy/Paste: sudo cp -r jre-7u40-linux-i586.tar.gz /usr/local/java
Type/Copy/Paste: cd /usr/local/java

64-bit Oracle Java on 64-bit Ubuntu Linux installation instructions:
Type/Copy/Paste: cd /home/"your_user_name"/Downloads
Type/Copy/Paste: sudo cp -r jdk-7u40-linux-x64.tar.gz /usr/local/java
Type/Copy/Paste: sudo cp -r jre-7u40-linux-x64.tar.gz /usr/local/java
Type/Copy/Paste: cd /usr/local/java

Unpack the compressed Java binaries, in the directory /usr/local/java
32-bit Oracle Java on 32-bit Ubuntu Linux installation instructions:
Type/Copy/Paste: sudo tar xvzf jdk-7u40-linux-i586.tar.gz
Type/Copy/Paste: sudo tar xvzf jre-7u40-linux-i586.tar.gz

64-bit Oracle Java on 64-bit Ubuntu Linux installation instructions:
Type/Copy/Paste: sudo tar xvzf jdk-7u40-linux-x64.tar.gz
Type/Copy/Paste: sudo tar xvzf jre-7u40-linux-x64.tar.gz

Double-check your directories. At this point, you should have two uncompressed binary directories in /usr/local/java for the Java JDK/JRE listed as:
Type/Copy/Paste: ls -a
jdk1.7.0_40
jre1.7.0_40

Edit the system PATH file /etc/profile and add the following system variables to your system path. Use vi, gedit or any other text editor, as root, open up /etc/profile.
Type/Copy/Paste: sudo gedit /etc/profile
or
Type/Copy/Paste: sudo vi /etc/profile

Scroll down to the end of the file using your arrow keys and add the following lines below to the end of your /etc/profile file:
Type/Copy/Paste:

export JAVA_HOME=/usr/local/java/jdk1.7.0_40
export PATH=$PATH:$JAVA_HOME/bin

Save the /etc/profile file and exit.

Reload your system wide PATH /etc/profile by typing the following command:
Type/Copy/Paste: . /etc/profile
Note your system-wide PATH /etc/profile file will reload after reboot of your Ubuntu Linux system

Test to see if Oracle Java was installed correctly on your system. Run the following commands and note the version of Java:

A successful installation of 32-bit Oracle Java will display:
Type/Copy/Paste: java -version
This command displays the version of java running on your system
You should receive a message which displays:
java version "1.7.0_40"
Java(TM) SE Runtime Environment (build 1.7.0_40-b40)
Java HotSpot(TM) Server VM (build 23.1-b03, mixed mode)
Type/Copy/Paste: javac -version
This command lets you know that you are now able to compile Java programs from the terminal.
You should receive a message which displays:
javac 1.7.0_40

A successful installation of Oracle Java 64-bit will display:
Type/Copy/Paste: java -version
This command displays the version of java running on your system
You should receive a message which displays:
java version "1.7.0_40"
Java(TM) SE Runtime Environment (build 1.7.0_40-b40)
Java HotSpot(TM) 64-Bit Server VM (build 23.6-b04, mixed mode)
Type/Copy/Paste: javac -version
This command lets you know that you are now able to compile Java programs from the terminal.
You should receive a message which displays:
javac 1.7.0_40

Congratulations, you just installed Oracle Java on your Linux system. Now reboot your Ubuntu Linux system. Afterwards, your system will be fully configured for running and developing Java programs. Later on you may want to try compiling and running your own Java programs by following this article How to Create your First Java Program on Ubuntu Linux