Introduction
Java is a programming technology originally developed by Sun Microsystems and later acquired by Oracle. Oracle Java is a proprietary implementation for Java that is free to download and use for commercial use, but not to redistribute, therefore it is not included in a officially maintained repository.
There are many reasons why you would want to install Oracle Java over OpenJDK. In this tutorial, we will not discuss the differences between the above mentioned implementations.
Assumptions
This tutorial assumes that you have an account with DigitalOcean, as well as a Droplet running Debian 7 or Ubuntu 12.04 or above. You will need root privileges (via sudo) to complete the tutorial.
You will need to know whether you are running a 32 bit or a 64 bit OS:
i46614161@i46614161:/usr/local/java/jdk1.8.0_05$ uname -m i686
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x86_64: 64 bit kernel
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i686: 32 bit kernel
Downloading Oracle Java JDK
Using your web browser, go to the Oracle Java SE (Standard Edition) website and decide which version you want to install:
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JDK: Java Development Kit. Includes a complete JRE plus tools for developing, debugging, and monitoring Java applications.
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Server JRE: Java Runtime Environment. For deploying Java applications on servers. Includes tools for JVM monitoring and tools commonly required for server applications.
In this tutorial we will be installing the JDK Java SE Development Kit 8 x64 bits. Accept the license and copy the download link into your clipboard. Remember to choose the right tar.gz (64 or 32 bits). Use wget to download the archive into your server:
wget --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u5-b13/jdk-8u5-linux-i586.tar.gz
Oracle does not allow downloads without accepting their license, therefore we needed to modify the header of our request. Alternatively, you can just download the compressed file using your browser and manually upload it using a SFTP/FTP client.
Always get the latest version from Oracle‘s website and modify the commands from this tutorial accordingly to your downloaded file.
Or U can visit the website directly and download the tar.gz file do not visa the command .
Installing Oracle JDK
In this section, you will need sudo privileges:
sudo sudo mkdir -p /usr/local/java
cd /home/"your_user_name"/Downloads
sudo cp -r jdk-8u5-linux-i586.tar.gz /usr/local/java/
cd /usr/local/java
sudo tar xvzf jdk-8u5-linux-i586.tar.gz
Setting Oracle JDK as the default JVM
In our case, the java executable is located under /usr/local/java/jdk1.8.0_05/bin/java . To set it as the default JVM in your machine run:
sudo update-alternatives --install /usr/bin/java java /usr/local/java/jdk1.8.0_05/bin/java 100
sudo update-alternatives --install /usr/bin/javac javac /usr/local/java/jdk1.8.0_05/bin/javac 100
Verify your installation
Verify that java has been successfully configured by running:
update-alternatives --display java
update-alternatives --display javac
The output should look like this:
java - auto mode link currently points to /usr/local/java/jdk1.8.0_05/bin/java /usr/local/java/jdk1.8.0_05/bin/java - priority 100 Current ‘best‘ version is ‘/usr/local/java/jdk1.8.0_05/bin/java‘.
javac - auto mode link currently points to /usr/local/java/jdk1.8.0_05/bin/javac /usr/local/java/jdk1.8.0_05/bin/javac - priority 100 Current ‘best‘ version is ‘/usr/local/java/jdk1.8.0_05/bin/javac‘.
Another easy way to check your installation is:
java -version
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