How to Install Java 9 JDK on Linux Systems

Java is a collection of software better known for it’s cross platform availability was developed by Sun Microsystems in 1995. Java platform is used by millions of applications and websites (specially used in banking sites) due to its fast, secure and reliable nature. Today, Java is everywhere, from desktops to data-centers, game consoles to scientific computers, mobile phones to the Internet, etc…

There are more than one version of Java can be installed and running on same computer and also it’s possible to have different version of JDK and JRE simultaneously 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).

A lots of Linux distribution comes with other version of Java called OpenJDK (not the one developed by Sun Microsystems and acquired by Oracle Corporation). OpenJDK is an open source implementation of Java application.

Latest stable release of Java version is 9.0.4.

Install Java 9 in Linux

1. Before installing Java, make sure to first 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.

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

# mkdir /opt/java && cd /opt/java

3. Now it’s time to download Java (JDK) 9 source tarball files for your system architecture by going to official Java download page.

For reference, we have provided the source tarball file-name, please select and download these below mentioned file only.


Alternatively, you may use wget command to download file directly into the /opt/java directory as shown below.

# cd /opt/java
# wget --no-cookies --no-check-certificate --header "Cookie: oraclelicense=accept-securebackup-cookie"

4. Once file has been downloaded, you may extract the tarball using tar command as shown below.

# tar -zxvf jdk-9.0.4_linux-x64_bin.tar.gz

5. Next, move to the extracted directory and use command update-alternatives to tell system where java and its executables are installed.

# cd jdk-9.0.4/
# update-alternatives --install /usr/bin/java java /opt/java/jdk-9.0.4/bin/java 100  
# update-alternatives --config java
Update Java Alternatives
Update Java Alternatives

6. Tell system to update javac alternatives as:

# update-alternatives --install /usr/bin/javac javac /opt/java/jdk-9.0.4/bin/javac 100
# update-alternatives --config javac
Update Javac Alternatives
Update Javac Alternatives

7. 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
Update Jar Alternatives
Update Jar Alternatives

8. 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
Set Java Environment Variables
Set Java Environment Variables

9. Now You may verify the Java version again, to confirm.

# 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)

Suggested: If you are not using OpenJDK (open source implementation of java), you may remove it as:

# yum remove openjdk-*      [On CentOs/RHEL]
# apt-get remove openjdk-*  [On Debian/Ubuntu]

Enable Java Support in Firefox

10. To enable Java 9 JDK Support in Firefox, you need to run following commands to enable Java module for Firefox.

On Debian, Ubuntu and Mint
# update-alternatives --install /usr/lib/mozilla/plugins/ /opt/java/jdk-9.0.4/lib/ 20000
On RHEL, CentOS and Fedora
# alternatives --install /usr/lib/mozilla/plugins/ /opt/java/jdk-9.0.4/lib/ 20000

11. Now verify the Java support by restarting Firefox and enter about:plugins on the address bar. You will get similar to below screen.

Java 8 Support in Firefox
Java 8 Support in Firefox

That’s all for now. Hope this post of mine will help you in setting oracle Java, the easiest way. I would like to know your view on this. Keep connected, Stay tuned! Like and share us and help us get spread.

A Passionate GNU/Linux Enthusiast and Software Developer with over a decade in the field of Linux and Open Source technologies.

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45 thoughts on “How to Install Java 9 JDK on Linux Systems”

  1. Hello, I am a lack experience engineer. please explain to me what is the meaning of 20000 at the end of the sentence, I could not find that at oracle official website.

    # update-alternatives --install /usr/lib/mozilla/plugins/ /opt/java/jdk-9.0.4/lib/ 20000
  2. I get this error when write # java -version

    Error occurred during initialization of VM
    java/lang/NoClassDefFoundError: java/lang/Object

  3. wget –no-cookies –no-check-certificate –header “Cookie:; oraclelicense=accept-securebackup-cookie” “”

    above command giving error
    HTTP request sent, awaiting response… 404 Not Found
    2017-09-10 21:53:31 ERROR 404: Not Found.

    Please explain

  4. Hi Guys, Here I am writing some simple steps to install JAVA JDK AND JRE on Linux systems.

    First download jdk-8u112-linux-x64.tar.gz and jre-8u112-linux-x64.tar.gz

    Note: Here I am sharing my Java installation instructions, which I have done in my Linux system using root user account or sudo privileges will also work.

    1. Switch to root user.

    amit@Deepin:~$sudo -i
    [sudo] password for amit: *******  
    {after this you will reach into root privileged}

    2. Create one folder where you would like to copy your both JDK and JRE software, In my case I place my software in /usr/local/java directory.

    So after downloading go into downloading directory folder mostly it will be: /home/amit/Downloads – in your case username will be yours.

    root@Deepin:~# cd /home/amit/Downloads
    root@Deepin:~# ls    
    jre-8u112-linux-x64.tar.gz	jdk-8u112-linux-x64.tar.gz

    3. Now copy both jdk and jre into your desire system location:

    root@Deepin:~# mkdir /usr/local/java
    root@Deepin:~#cp jre-8u112-linux-x64.tar.gz /usr/local/java
    root@Deepin:~#cp jdk-8u112-linux-x64.tar.gz /usr/local/java

    4. Extract the content of both files.

    root@Deepin:~#cd /usr/local/java
    root@Deepin:~#tar zxvf jre-8u112-linux-x64.tar.gz
    root@Deepin:~#tar zxvf jdk-8u112-linux-x64.tar.gz

    Verify the contents

    jdk1.8.0_112 	jdk-8u112-linux-x64.tar.gz
    jre1.8.0_112 	jre-8u112-linux-x64.tar.gz

    5. Now set tha Java environment variables.

    root@Deepin:~# gedit /etc/profile

    At the bottom you just copy and paste below lines.

    unset _JAVA_OPTIONS
    export JAVA_HOME
    export JRE_HOME
    export PATH
    Else, if only JDK installation Require
    unset _JAVA_OPTIONS
    export JAVA_HOME
    export JRE_HOME
    export PATH

    Now just save and close page:

    6. After this perform some commands in terminal.

    root@Deepin:~# update-alternatives --install "/usr/bin/java" "java" /usr/local/java/jre1.8.0_112/bin/java" 1
    root@Deepin:~# update-alternatives --install "/usr/bin/javac" "javac" /usr/local/java/jdk1.8.0_112/bin/javac" 1
    root@Deepin:~# update-alternatives --install "/usr/bin/javaws" "javaws" /usr/local/java/jre1.8.0_112/bin/javaws" 1
    root@Deepin:~# update-alternatives --set java /usr/local/java/jre1.8.0_112/bin/java
    root@Deepin:~# update-alternatives --set javac /usr/local/java/jdk1.8.0_112/bin/javac
    root@Deepin:~# update-alternatives --set javaws /usr/local/java/jre1.8.0_112/bin/javaws
    root@Deepin:~# . /etc/profile

    7. Finally, you can check java version, JAVA HOME, and JRE Home. PATH.

    root@Deepin:~# echo $HOME

    root@Deepin:~# echo $PATH

    root@Deepin:~# echo $JAVA_HOME
    root@Deepin:~# echo $JRE_HOME
    root@Deepin:~# java -version
    java version "1.8.0_112"
    Java(TM) SE Runtime Environment (build 1.8.0_112-b15)
    Java HotSpot(TM) 64-Bit Server VM (build 25.112-b15, mixed mode)


    • yes because he wrote export command in wrong way, you should write it as :
      export PATH=/opt/java/jdk1.8.0_45/bin:/opt/java/jdk1.8.0_45/jre/bin

      then you will notice that the new version installed


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