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javalinuxubuntujava-9

How to config Java 9 in Ubuntu

JDK 9 reached yesterday，and I downloaded the jdk-9_linux-x64_bin.tar.gz.

directory

xx@xx:/usr/lib/jvm/jdk-9$ ls

bin  conf  include  jmods  legal  lib README.html  release

It and java8 are very different. I like to configure the same as java8,

export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_25  
export JRE_HOME=${JAVA_HOME}/jre  
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib  
export PATH=${JAVA_HOME}/bin:$PATH

But java9 has no jre. So I configured it like that (Add these in the .bashrc file)

export JAVA_HOME=/usr/lib/jvm/java-9 
export CLASSPATH=.:$JAVA_HOME/lib
export PATH=$JAVA_HOME/bin:$PATH

and run source ~/.bashrc

But java version is still no change. My operating system is Ubuntu 14.04.3.

Did i do anything wrong?

Solution

  • Installation and Configuration of JDK9 is step by step given below:

    Install JDK9 in Ubuntu:

    sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java9-installer

    Make it as default:

    sudo apt-get install oracle-java9-set-default

    Changed in .bashrc, /etc/environment and also set default using

    3 sections to change java configuration.

    .bashrc:

    export JAVA_HOME=/usr/lib/jvm/java-9-oracle
export PATH=$JAVA_HOME/bin:$PATH

    /ect/environment:

    JAVA_HOME="/usr/lib/jvm/java-9-oracle"
PATH=$PATH:$JAVA_HOME/bin

    Then run the following command and set

    sudo update-alternatives --config java

sudo update-alternatives --config javac

    Then run the command

    source /etc/environment

    Check in terminal:

    java -version
echo $JAVA_HOME
which java
which javac

    Issue#1:

    Execute "source /etc/environment" in every shell where you want the variables to be updated:

    $ source /etc/environment

    Resource Link: https://stackoverflow.com/a/5994031

    Issue#2:

    Just write JAVA_HOME="/usr/lib/jvm/java-9-oracle" on your /etc/environment, without the "export"

    /etc/environment is supposed to contain a set of environment variables given as key=value pairs. It is not a shell script, so you can't use shell commands such as export in it.

    Resource Link:

    How to properly set JAVA_HOME in /etc/environment

    Issue#3:

    To check if java is properly installed:

    $ which java

$ which javac

    You should get similar output:

    /usr/bin/java

    Resource Link: https://stackoverflow.com/a/23124805

    Issue#4:

    To remove Oracle JDK completely, run the commands below:

    Completely remove criteria:

    sudo apt-get remove oracle-java9-installer
sudo apt-get remove --auto-remove oracle-java9-installer
sudo apt-get purge oracle-java9-installer
sudo apt-get purge --auto-remove oracle-java9-installer

    Resource Link:

    https://www.howtoinstall.co/en/ubuntu/trusty/tomcat7?action=remove