Updated: May 29, 2020 by Unity
How to Download and Install Oracle JAVA 8 on Ubuntu 18.04 LTS Manually.
Table of Contents
Introduction
Java 8 Features:
Prerequisites
Step 1: Download Oracle Java 8
Step 2: Copy downloaded Setup and Extract
Step 3: Install Oracle Java 8 on ubuntu with Alternatives
Step 4: Verify Update Alternatives
Step 5: Setting the JAVA_HOME and JRE_HOME Environment Variables
Step 6: Verify Java Version
Conclusion
Related Articles:
Introduction
Java is a set of software and specifications developed at Sun Microsystems. There are two tyes of Java Platforms are JDK (Java Development Kit) and JRE (Java Runtime Environment). Both are helpful for deploying applications on servers and debugging, JVM monitoring,developing.
Java是由Sun Microsystems 开发的一组软件和规范。Java平台有两种类型，分别是JDK(Java开发工具包)和JRE(Java运行时环境)两者都有助于在服务器上部署应用程序及调试, JVM监视, 开发
Java 8 Features:
To know more detailed features go through this link.
Prerequisites
- Ubuntu Server 18.04 LTS
- SSH access with sudo privileges
To check Ubuntu version:
$ uname -a
OR
$ cat /etc/os-release
Output
NAME="Ubuntu"
VERSION="18.04.3 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.3 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic
Follow the below steps to Install Oracle Java 8 on Ubuntu Manually using command line.
Step 1: Download Oracle Java 8
Generally Oracle will not allow to download directly without accepting their licences. We have to create one account in Oracle java website by your personal or official mail. After accepting licence download the application from browser to local machine.
This link takes you to the Oracle home website Oracel Java SRE.
Once you opened above link goto “JAVA SE Development Kit 8u251” section, download “jdk-8u251-linux-x64.tar.gz” setup for Ubuntu click on “Accept License Agreement” Check Box.
After downloading into local machine, using SCP/SFTP/FTP transfer the file from local machine to Ubuntu server.
**Step 2: Copy downloaded Setup and Extract **
Create a directory /opt/jdk
$ sudo mkdir -p /opt/jdk
Copy the tar file from the directory copied from local machine to server to /opt/jdk folder and execute below command:
$ sudo cp -rf /home/unity/jdk-8u251-linux-x64.tar.gz /opt/jdk/
$ cd /opt/jdk
$ sudo tar -zxvf jdk-8u251-linux-x64.tar.gz
**Step 3: Install Oracle Java 8 on ubuntu with Alternatives **
Use update-alternatives command to configure java on your system
$ sudo update-alternatives --install /usr/bin/java java /opt/jdk/jdk1.8.0_251/bin/java 100
$ sudo update-alternatives --install /usr/bin/javac javac /opt/jdk/jdk1.8.0_251/bin/javac 100
$ sudo update-alternatives --install /usr/bin/jar jar /opt/jdk/jdk1.8.0_251/bin/jar 100
After executing above command it shows below output:
Output:
update-alternatives: using /opt/jdk/jdk1.8.0_251/bin/java to provide /usr/bin/java (java) in auto mode
update-alternatives: using /opt/jdk/jdk1.8.0_251/bin/javac to provide /usr/bin/javac (javac) in auto mode
update-alternatives: using /opt/jdk/jdk1.8.0_251/bin/jar to provide /usr/bin/jar (jar) in auto mode
Note : Its not particularly o/p if you have installed open jdk before
Step 4: Verify **Update Alternatives **
Enter below command shows output:
$ sudo update-alternatives --display java
java - manual mode
link best version is /usr/lib/jvm/java-13-oracle/bin/java
link currently points to /opt/jdk/jdk-13.0.2/bin/java
link java is /usr/bin/java
slave java.1.gz is /usr/share/man/man1/java.1.gz
/opt/jdk/jdk-12.0.2/bin/java - priority
/opt/jdk/jdk-13.0.2/bin/java - priority 1
/opt/jdk/jdk1.8.0_241/bin/java - priority 100
/usr/lib/jvm/java-13-oracle/bin/java - priority 1091
slave java.1.gz: /usr/lib/jvm/java-13-oracle/man/man1/java.1.gz
To change for alternative mode:
$ sudo update-alternatives --config java
It prompts for selecting by 0,1,2..so choose accordingly:
Output
There are 4 choices for the alternative java (providing /usr/bin/java).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/lib/jvm/java-13-oracle/bin/java 1091 auto mode
1 /opt/jdk/jdk-12.0.2/bin/java 2 manual mode
* 2 /opt/jdk/jdk-13.0.2/bin/java 1 manual mode
3 /opt/jdk/jdk1.8.0_241/bin/java 100 manual mode
4 /usr/lib/jvm/java-13-oracle/bin/java 1091 manual mode
Press <enter> to keep the current choice[*], or type selection number: 3
update-alternatives: using /opt/jdk/jdk1.8.0_241/bin/java to provide /usr/bin/java (java) in manual mode
Step 5: Setting the JAVA_HOME and JRE_HOME Environment Variables
To define the enviroment variable:
$ sudo vim /etc/environment
Paste the below variable on the file:
JAVA_HOME=/opt/jdk/jdk1.8.0_251
JRE_HOME=/opt/jdk/jdk1.8.0_251/jre
To check variables defined:
$ source /etc/environment
$ echo $JAVA_HOME
Output
/opt/jdk/jdk1.8.0_251
$ sudo apt-get update
Step 6: Verify Java Version
To check the java version:
$ java -version
Output
java version "1.8.0_251"
If you seeing output like above then we have successfully set up the Java 8 on Ubuntu.
Conclusion
In this article, We have downloaded Oracle Java 8 from official site, installed using command line, configured JAVA_HOME and JRE_HOME, verified installed version.
How to Download and Install Oracle JAVA 8 on Ubuntu 18.04/16.04 LTS