Installing JDK on Linux

We can install JDK with the binary file (.tar.gz).

We need to make directory, where we need to install Java. For global access for all users, preferably in the directory /usr/java

mkdir /usr/java && cd /usr/java

We can download Java (JDK) 9 from Java Download

For reference, We can download the Source tarball file-name with given below
#jdk-9.0.4_linux-x64_bin.tar.gz

Alternatively, we can download with wget command as given below in to /usr/java

# cd /usr/java
# wget --no-cookies --no-check-certificate --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/9.0.4+11/c2514751926b4512b076cc82f959763f/jdk-9.0.4_linux-x64_bin.tar.gz

Extract tarball wite given below
#tar -zxvf jdk-9.0.4_linux-x64_bin.tar.gz
Use update-alternatives command to change the Java environment path
cd /usr/java/jdk-9.0.4/
For Java to select default 
# update-alternatives --install /usr/bin/java java /usr/java/jdk-9.0.4/bin/java 100  
# update-alternatives --config java
For Javac to select default
# update-alternatives --install /usr/bin/javac javac /usr/java/jdk-9.0.4/bin/javac 100
# update-alternatives --config javac

Similarly, update jar alternatives as

# update-alternatives –install /usr/bin/jar jar /opt/java/jdk-9.0.4/bin/jar 100

# update-alternatives –config jar

Setting up Java Environment Variables

# export JAVA_HOME=/opt/java/jdk-9.0.4/
# export JRE_HOME=/opt/java/jdk-9.0.4/jre
# export PATH=$PATH:/opt/java/jdk-9.0.4/bin:/opt/java/jdk-9.0.4/jre/bin

To Check java version from the linux

# java -version

java version "9.0.4"
Java(TM) SE Runtime Environment (build 9.0.4+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.4+11, mixed mode)