OS / Ubuntu16.04 / Uncategorized

Uninstalling JAVA from Ubuntu

  1. Remove all the Java related packages (Sun, Oracle, OpenJDK, IcedTea plugins, GIJ):
    dpkg-query -W -f='${binary:Package}\n' | grep -E -e '^(ia32-)?(sun|oracle)-java' -e '^openjdk-' -e '^icedtea' -e '^(default|gcj)-j(re|dk)' -e '^gcj-(.*)-j(re|dk)' -e '^java-common' | xargs sudo apt-get -y remove
    sudo apt-get -y autoremove
  2. Purge config files:
    dpkg -l | grep ^rc | awk '{print($2)}' | xargs sudo apt-get -y purge
  3. Remove Java config and cache directory:
    sudo bash -c 'ls -d /home/*/.java' | xargs sudo rm -rf
  4. Remove manually installed JVMs:
    sudo rm -rf /usr/lib/jvm/*
  5. Remove Java entries, if there is still any, from the alternatives:
    for g in ControlPanel java java_vm javaws jcontrol jexec keytool mozilla-javaplugin.so orbd pack200 policytool rmid rmiregistry servertool tnameserv unpack200 appletviewer apt extcheck HtmlConverter idlj jar jarsigner javac javadoc javah javap jconsole jdb jhat jinfo jmap jps jrunscript jsadebugd jstack jstat jstatd native2ascii rmic schemagen serialver wsgen wsimport xjc xulrunner-1.9-javaplugin.so; do sudo update-alternatives --remove-all $g; done
  6. Search for possible remaining Java directories:
    sudo updatedb
    sudo locate -b '\pack200'

    If the command above produces any output like /path/to/jre1.6.0_34/bin/pack200 remove the directory that is parent of bin, like this: sudo rm -rf /path/to/jre1.6.0_34.

Installing Java

Step 1: Install Java 8 (JDK 8)
Open terminal and enter the following commands.
sudo add-apt-repository -y ppa:webupd8team/java
sudo apt-get update
echo debconf shared/accepted-oracle-license-v1-1 select true | sudo debconf-set-selections
echo debconf shared/accepted-oracle-license-v1-1 seen true | sudo debconf-set-selections
sudo apt-get -y install oracle-java8-installer

Setup JAVA Environment
sudo apt-get -y install oracle-java8-set-default

Step 2: Verify JAVA Version
After successfully installing oracle java using above step verify installed version using following command.
$ java -version
You see output similar to this.
java version “1.8.0_25”
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)

Installing JAVA on CentOS

How to Install JAVA 8 (JDK/JRE 8u131) on CentOS/RHEL 7/6 and Fedora 25

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