Unix: how to install java

sudo apt-get updatesudo apt-get install openjdk-7-jdk

Verification:   Java -version

or

For each host in cluster:


cd /usr/java/jdk1.7.0_67-cloudera/
Use alternatives command to install java. alternatives command is available in chkconfig package:


alternatives --install /usr/bin/java java /usr/java/jdk1.7.0_67-cloudera/bin/java 2

alternatives --config java

     There is 1 program that provides 'java'.

     Selection    Command

     -----------------------------------------------

     *+ 1           /usr/java/jdk1.8.0_31/bin/java

     Enter to keep the current selection[+], or type selection number:
enter 1 and press enter.

Setup javac and jar commands path using alternatives:


alternatives --install /usr/bin/jar jar /usr/java/jdk1.7.0_67-cloudera/bin/jar 2

alternatives --install /usr/bin/javac javac /usr/java/jdk1.7.0_67-cloudera/bin/javac 2

alternatives --set jar  /usr/java/jdk1.7.0_67-cloudera/bin/jar

alternatives --set javac /usr/java/jdk1.7.0_67-cloudera/bin/javac
Set the Java environment variables using following commands:


export JAVA_HOME=/usr/java/jdk1.7.0_67-cloudera

export JRE_HOME=/usr/java/jdk1.7.0_67-cloudera/jre

export PATH=$PATH:/usr/java/jdk1.7.0_67-cloudera/bin:/usr/java/jdk1.7.0_67-cloudera/jre/bin

Check the installed version of java using following command:


java –version