In this article, We are going to perform How to Download and Install Oracle JAVA 8 on CentOS 7 Manually or any cloud VM instance like Amazon EC2, Azure VM, Google Compute Engine with preinstalled CentOS 7.

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 8 Features:

Java 8 provides following features,

• ForEach() method
• Functional interfaces
• Base64 Encode Decode
• Parallel array sorting
• Nashorn JavaScript Engine,
• Parallel Array Sorting
• Type and Repating Annotations
• java.lang and java.util Packages

To know more detailed features go through this link.

Prerequisites

• CentOS 7 with Minimal Installation
• SSH access with sudo privileges

To check CentOS version:

$ uname -a

OR

$ cat /etc/os-release

Output:

$ cat /etc/os-release
NAME="CentOS Linux"
VERSION="7 (Core)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="7"
PRETTY_NAME="CentOS Linux 7 (Core)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:7"
HOME_URL="https://www.centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7"
CENTOS_MANTISBT_PROJECT_VERSION="7"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="7"

Follow the below steps to Install Oracle Java 8 on CentOS 7 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 8u231” section, click on “Accept License Agreement” Radio button and download “jdk-8u231-linux-x64.tar.gz” setup for CentOS 7

After downloading into local machine,using SCP/SFTP/FTP transfer the file from local machine to CentOS 7 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/sivasai/jdk-8u231-linux-x64.tar.gz /opt/jdk/

$ cd /opt/jdk/

$ sudo tar -zxf jdk-8u231-linux-x64.tar.gz

Now unarchived the file and check the content by long-list:

# ls

Output:

$ ls

jdk1.8.0_231 jdk-8u231-linux-x64.tar.gz

Step 3: Install Oracle Java 8 on CentOS 7 with Alternatives

$ sudo update-alternatives --install /usr/bin/java java /opt/jdk/jdk1.8.0_231/bin/java 100

update-alternatives: using /opt/jdk/jdk1.8.0_231/bin/java to provide /usr/bin/java (java) in auto mode

Note : Its not particularly o/p if you have installed open jdk before

Step 4: Verify Update Alternatives

$ sudo update-alternatives --display java

java - auto mode
  link best version is /opt/jdk/jdk1.8.0_231/bin/java
  link currently points to /opt/jdk/jdk1.8.0_231/bin/java
  link java is /usr/bin/java
/opt/jdk/jdk1.8.0_231/bin/java - priority 100
/opt/jdk/jdk1.8.0_231/bin/javac - priority 100

$ sudo update-alternatives --config java

$ sudo update-alternatives --config java

There are 3 programs which provide 'java'.

  Selection    Command
-----------------------------------------------
*+ 1           java-1.8.0-openjdk.x86_64 (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/jre/bin/java)
   2           java-1.7.0-openjdk.x86_64 (/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.191-2.6.15.4.el7_5.x86_64/jre/bin/java)
   3           /opt/jdk/jdk1.8.0_231/bin/java

Enter to keep the current selection[+], or type selection number: 3

Step 5: Setting the JAVA_HOME and JRE_HOME Environment Variables

$ sudo  nano /etc/environment

JAVA_HOME=/opt/jdk/jdk1.8.0_231
JRE_HOME=/opt/jdk/jdk1.8.0_231/jre

$ source /etc/environment

$ echo $JAVA_HOME

/opt/jdk/jdk1.8.0_231

$ sudo yum update

$ java -version

$ java -version

java version "1.8.0_231"
Java(TM) SE Runtime Environment (build 1.8.0_231-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.231-b11, mixed mode)