By default, all Linux distributions comes with openjdk preinstalled. If you want to install and use Oracle Java JDK/JRE on your system, Just follow the steps below. In this tutorial, let us see how to install and configure latest Oracle Java JDK on CentOS 6.5 server, although It should work on other RPM based distributions such as RHEL 6.x, Scientific Linux 6.x and Fedora etc.
First of all, update your server.
yum install update
Then, search for if any older JDK versions are installed in your system.
rpm -qa | grep -E '^open[jre|jdk]|j[re|dk]'
Sample output:
java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.i686
eject-2.1.5-17.el6.i686
perl-Object-Accessor-0.34-136.el6.i686
java-1.7.0-openjdk-1.7.0.45-2.4.3.4.el6_5.i686
openjpeg-libs-1.3-10.el6_5.i686
Check for already installed Java:
java -version
Sample output:
java version "1.7.0_45"
OpenJDK Runtime Environment (rhel-2.4.3.4.el6_5-i386 u45-b15)
OpenJDK Client VM (build 24.45-b08, mixed mode, sharing)
As you see in the above output, Java 1.6 and java 1.7 have been installed on my server. So, I removed both of them using the following commands:
yum remove java-1.6.0-openjdk
yum remove java-1.7.0-openjdk
Download And Install Oracle Java JDK
At the time of writing this tutorial, the latest Java JDK version is JDK 8u5 . First, let us download the latest Java version.
Go to the Oracle Java download page and download the required version depending upon your distribution architecture.
As I use 32bit CentOS server, I have downloaded the 32bit rpm package.
Then, go the directory where you’ve downloaded the jdk package and run the following command to install it.
rpm -ivh jdk-8u5-linux-i586.rpm
Sample output:
Preparing... ########################################### [100%] 1:jdk ########################################### [100%] Unpacking JAR files...
rt.jar...
jsse.jar...
charsets.jar...
tools.jar...
localedata.jar...
jfxrt.jar...
plugin.jar...
javaws.jar...
deploy.jar...
Check Java version
Now, check for the installed JDK version in your system using command:
java -version
Sample output:
java version "1.8.0_05"
Java(TM) SE Runtime Environment (build 1.8.0_05-b13)
Java HotSpot(TM) Client VM (build 25.5-b02, mixed mode, sharing)
As you see above, latest java 1.8 has been installed.
What if I didn’t remove the old JDK versions from my system?
As I mentioned before, make sure you have removed all old JDK versions from your system. If you didn’t remove the older versions from your server before installing latest JDK version, you should tell your system, from where java should be executed.
By default, the JDK 1.8.x will be installed in /usr/java/jdk1.8.0_05/ location. In order to tell our system, from where java should be executed, we need to run the following commands one by one.
alternatives --install /usr/bin/java java /usr/java/jdk1.8.0_05/jre/bin/java 20000 alternatives --install /usr/bin/jar jar /usr/java/jdk1.8.0_05/bin/jar 20000 alternatives --install /usr/bin/javac javac /usr/java/jdk1.8.0_05/bin/javac 20000 alternatives --install /usr/bin/javaws javaws /usr/java/jdk1.8.0_05/jre/bin/javaws 20000 alternatives --set java /usr/java/jdk1.8.0_05/jre/bin/java alternatives --set jar /usr/java/jdk1.8.0_05/bin/jar alternatives --set javac /usr/java/jdk1.8.0_05/bin/javac alternatives --set javaws /usr/java/jdk1.8.0_05/jre/bin/javaws
All done. Let us check the alternatives.
ls -lA /etc/alternatives/
Sample output:
lrwxrwxrwx. 1 root root 29 May 9 16:40 jar -> /usr/java/jdk1.8.0_05/bin/jar lrwxrwxrwx. 1 root root 34 May 9 16:39 java -> /usr/java/jdk1.8.0_05/jre/bin/java lrwxrwxrwx. 1 root root 31 May 9 16:41 javac -> /usr/java/jdk1.8.0_05/bin/javac lrwxrwxrwx. 1 root root 36 May 9 16:41 javaws -> /usr/java/jdk1.8.0_05/jre/bin/javaws
That’s it. Now check for the java version using command:
java -version
Sample output:
java version "1.8.0_05"
Java(TM) SE Runtime Environment (build 1.8.0_05-b13)
Java HotSpot(TM) Client VM (build 25.5-b02, mixed mode, sharing)
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