java tutorial - How to install Java on Linux - java programming - learn java - java basics - java for beginners

Install JAVA on Linux Systems

  • The Java can be installed and running on same computer as well as it’s possible to have different version of JDK and JRE at the same time on a machine, actually there are abundant of applications that requires Java-jre (Java Runtime Environment) and those who are developer required Java-sdk (Software Development Kit).
  • Many of Linux distribution comes under additional version of Java known as OpenJDK (not the one developed by Sun Microsystems and then acquired by Oracle Corporation).
  • The OpenJDK is open source implementation of Java application.

Steps to Install Java in Linux

Step 1

  • Before installing Java, make sure to initial verify the version of installed Java.
# java -version
java version "1.7.0_75"
OpenJDK Runtime Environment (IcedTea 2.5.4) (7u75-2.5.4-2)
OpenJDK 64-Bit Server VM (build 24.75-b04, mixed mode)
  • It’s clear from the output above that the installed version of Java is OpenJDK 1.7.0_75.

Step 2

  • Make a directory where you want to install Java. For global access (for all users) install it preferably in the directory /opt/java. /opt/java.
# mkdir /opt/java && cd /opt/java

Step 3

  • Now download Java (JDK) 8u45 source tarball files for your system architecture by going to official Java download page.
  • For reference, we have provided the source tarball file-names, please select and download these under mentioned files only.
jdk-8u45-linux-i586.tar.gz		[For 32-bit Systems]
jdk-8u45-linux-x64.tar.gz		[For 64-bit Systems]
  • Otherwise, you may use wget command to download files directly into the /opt/java directory as shown below.
--------------- For 32-bit Systems ---------------
# cd /opt/java
# wget --no-cookies --no-check-certificate --header "Cookie:; oraclelicense=accept-securebackup-cookie" ""
--------------- For 64-bit Systems --------------
# cd /opt/java
# wget --no-cookies --no-check-certificate --header "Cookie:; oraclelicense=accept-securebackup-cookie" ""

Step 4

  • Once file has been downloaded, you may extract the tarball using tar command as shown below.
# tar -zxvf jdk-8u45-linux-i586.tar.gz		[For 32-bit Systems]
# tar -zxvf jdk-8u45-linux-x64.tar.gz		[For 64-bit Systems]

Step 5

  • From that point onwards, move to the already extracted directory and to utilize command update-alternatives then to inform system where java as well as its executables are installed.
# cd jdk1.8.0_45/
# update-alternatives --install /usr/bin/java java /opt/java/jdk1.8.0_45/bin/java 100  
# update-alternatives --config java
 Update java alternatives

Learn Java - Java tutorial - Update java alternatives - Java examples - Java programs

Step 6

  • System to update javac alternatives as,
# update-alternatives --install /usr/bin/javac javac /opt/java/jdk1.8.0_45/bin/javac 100
# update-alternatives --config javac
 Update javac alternatives

Learn Java - Java tutorial - Update javac alternatives 1 - Java examples - Java programs

Step 7

  • Likewise, update jar alternatives as:
# update-alternatives --install /usr/bin/jar jar /opt/java/jdk1.8.0_45/bin/jar 100
# update-alternatives --config jar
 Update Jar Alternatives

Learn Java - Java tutorial - Update Jar Alternatives - Java examples - Java programs

Step 8

  • Now you have to setting up Java Environment Variables.
# export JAVA_HOME=/opt/java/jdk1.8.0_45/	
# export JRE_HOME=/opt/java/jdk1.8.0._45/jre 	
# export PATH=$PATH:/opt/java/jdk1.8.0_45/bin:/opt/java/jdk1.8.0_45/jre/bin
 Set Java Path

Learn Java - Java tutorial - Set Java Path - Java examples - Java programs

Step 9

  • Presently you can check the Java version another time, to confirm.
# java -version
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)
  • Optional: If you are not using OpenJDK (open source implementation of java), you may eliminate it as:
# apt-get remove openjdk-*

Enable Java Support in Firefox

Step 10

  • To enable Java 8 JDK 8u45 Support in Firefox, you require running the following commands to allow Java module for Firefox.

On Debian, Ubuntu and Mint

--------------- For 32-bit Systems ---------------
# update-alternatives --install /usr/lib/mozilla/plugins/ /opt/java/jdk1.8.0_45/jre/lib/i386/ 20000
--------------- For 64-bit Systems ---------------
# update-alternatives --install /usr/lib/mozilla/plugins/ /opt/java/jdk1.8.0_45/jre/lib/amd64/ 20000

On RHEL, CentOS and Fedora

--------------- For 32-bit Systems ---------------
# alternatives --install /usr/lib/mozilla/plugins/ /opt/java/jdk1.8.0_45/jre/lib/i386/ 20000
--------------- For 64-bit Systems ---------------
# alternatives --install /usr/lib/mozilla/plugins/ /opt/java/jdk1.8.0_45/jre/lib/amd64/ 20000

Step 11

  • Finally verify the Java support by restart the Firefox and enter about:plugins on the address bar. You will get similar to below screen.
 Java support in firefox

Learn Java - Java tutorial - Java support in firefox - Java examples - Java programs

Related Searches to How to install Java on Linux