How to manually install a new java path to the alternatives java group? How to upgrade Linux java from java version "1.6.0_24" to java version "1.8.0_121"

Step 1 : Check the already installed JAVA in Linux.


Step 2: Command  >>  java -version


[in my case -- java version "1.6.0_24"
OpenJDK Runtime Environment (IcedTea6 1.11.1) (rhel-1.45.1.11.1.el6-x86_64)
                     OpenJDK 64-Bit Server VM (build 20.0-b12, mixed mode) ]


Step 3: Command  >>  which java

                     [ /usr/bin/java - in all linux its same - its bin file for java ]


Step 4: Command >>   cd /usr/lib/jvm

[ to check libraries of already installed java ]



Step 5: Download new JAVA from oracle


 Use this Link: http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
     
jdk-8u121-linux-x64.tar.gz



Step 6: move this file to     /usr/lib/java/  location {optional}

            command >>     mv jdk-8u121-linux-x64.tar.gz  /usr/lib/java
                         


Step 7: command to extract >>   tar -xvzf jdk-8u121-linux-x64.tar.gz

                                             

Step 8: Command >>

  update-alternatives --install "/usr/bin/java" "java" /usr/lib/java/jdk1.8.0_121/bin/java 1

[where,

/usr/bin/java -- its bin file for java to install

/usr/lib/java/jdk1.8.0_121/bin/java -- New JDK bin

1 is for priority ]


Step 9: Command >>  update-alternatives --set java /usr/lib/java/jdk1.8.0_121/bin/java

                 



Step 10: check the version   command >>  java -version


Step 11 :  command >>  whereis java



Using alternatives, check if changes have taken effect and finally confirm the java version on system.

Step 12 : command >>   alternatives --config java

---------------------------------------------------------------------------------------------------------------
[You can also change the selection of java in System]
                 
Output:

There are 3 programs which provide 'java'.

Selection    Command
-----------------------------------------------
*  1           /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/java
  2           /java/jdk1.8.0_121/bin/java
+ 3            /usr/lib/java/jdk1.8.0_121/bin/java

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


       

Reference DOC link: https://access.redhat.com/solutions/1161843



Thanks to all.