I'm a little confused at the moment. My back story in short, is that I'm trying to set up a Minecraft server on an Ubuntu server I've recently set up, obviously to do this I needed Java, but after googling for a short while I wasn't entirely sure whether it is possible (or legal?) to do so in Ubuntu 12.04 due to licensing type issues - so I installed open JDK instead which appears not to work properly with the Minecraft server software (I half expected this) I'm now considering uninstalling open JDK and instead trying to get proper Java on there instead, my question is, is this possible? Is it Legal? And if so how do I go about doing it? Because I'm finding it very difficult to find any instructions on how to do so for 12.04 . . . Answers The legal problems you are referring are about the distribution of Oracle Java. Its license prevents that it could be provided in the default repositories, but its perfectly legal to download and install it. Probably the easiest way is to use the WebUpd8 ppa: sudo add-apt-repository ppa:webupd8team/java sudo apt-get update sudo apt-get install oracle-java7-installer This will run a script that will download and install Oracle Java 7 (JDK) from the official website, so it is perfectly legal. If you just want JRE the best way is probably download and install it manually from Oracle website. Are "PPA's" safe to add to my system, and what are some "red flags" to watch out for? http://www.iasptk.com/ubuntu-oracle-java7-jdk7-jre7-firefox-chrome-plugin Ubuntu. Oracle Java 7. Install the Oracle JDK 7. Install the Oracle JRE 7. Install the Firefox/Chrome Oracle Java 7 plugin Install the JDK Download the 32bit or 64bit Linux "compressed binary file" - it has a ".tar.gz" file extension Uncompress it $ tar -xvf jdk-7u7-linux-i586.tar.gz JDK 7 package is extracted into ./jdk1.7.0_07 directory. - Now move the JDK 7 directory to /usr/lib $ sudo mv jdk1.7.0_07 /usr/lib/jvm/jdk1.7.0_07 Now run $ sudo update-alternatives --config java Which outputs: There are 2 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ———————————————————— * 0 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 auto mode 1 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 manual mode 2 /usr/lib/jvm/java-6-sun/jre/bin/java 63 manual mode Press enter to keep the current choice[*], or type selection number: Remember the last number and press enter to exit this utility i.e. in this example remember the number 2. if only one alternative is shown then remember the number 0 Now run $ sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0_07/jre/bin/java 3 This will add your new JDK 7 installation into alternatives list i.e. use the remembered number + 1 i.e. 3 in the example above. Run $ sudo update-alternatives --config java You will see output similar one below - choose the number of jdk1.7.0_07 e.g. 3: There are 3 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ———————————————————— * 0 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 auto mode 1 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 manual mode 2 /usr/lib/jvm/java-6-sun/jre/bin/java 63 manual mode 3 /usr/lib/jvm/jdk1.7.0_07/jre/bin/java 3 manual mode Press enter to keep the current choice[*], or type selection number: 3 update-alternatives: using /usr/lib/jvm/jdk1.7.0_07/jre/bin/java to provide /usr/bin/java (java) in manual mode. Check the version of you new JDK 7 installation: $ java -version java version "1.7.0_07" Java(TM) SE Runtime Environment (build 1.7.0_07-b13) Java HotSpot(TM) Server VM (build 22.0-b10, mixed mode) Install the JRE Download the 32bit or 64bit Linux "compressed binary file" - it has a ".tar.gz" file extension Uncompress it $ tar -xvf jre-7u7-linux-i586.tar.gz JRE 7 package is extracted into ./jre1.7.0_07 directory. - Now move the JRE 7 directory to /usr/lib $ sudo mv jre1.7.0_07 /usr/lib/jvm/jre1.7.0_07 Now run $ sudo update-alternatives --config java Which outputs: There are 2 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ———————————————————— * 0 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 auto mode 1 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 manual mode 2 /usr/lib/jvm/java-6-sun/jre/bin/java 63 manual mode Press enter to keep the current choice[*], or type selection number: Remember the last number and press enter to exit this utility i.e. in this example remember the number 2. if only one alternative is shown then remember the number 0 Now run $ sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jre1.7.0_07/bin/java 3 This will add your new JRE 7 installation into alternatives list i.e. use the remembered number + 1 i.e. 3 in the example above. Run $ sudo update-alternatives --config java You will see output similar one below - choose the number of jre1.7.0_07 i.e. 3: There are 3 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ———————————————————— * 0 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 auto mode 1 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 manual mode 2 /usr/lib/jvm/java-6-sun/jre/bin/java 63 manual mode 3 /usr/lib/jvm/jre1.7.0_07/jre/bin/java 3 manual mode Press enter to keep the current choice[*], or type selection number: 3 update-alternatives: using /usr/lib/jvm/jre1.7.0_07/jre/bin/java to provide /usr/bin/java (java) in manual mode. N.B. if there was no previous java installation then the new JRE will be the default and you will not see the above. Check the version of you new JRE 7 installation: $ java -version java version "1.7.0_07" Java(TM) SE Runtime Environment (build 1.7.0_07-b13) Java HotSpot(TM) Server VM (build 22.0-b10, mixed mode) Install the Firefox/Chrome plugin In a terminal: $ mkdir ~/.mozilla/plugins Remove the IcedTea plugin, if it has been installed. $ sudo apt-get remove icedtea6-plugin Remove a former version of the Java plugin (may or may not be present) $ sudo rm ~/.mozilla/plugins/libnpjp2.so Now you can install the plugin, by creating a symbolic link (you tell Firefox, where the plugin is located). $ sudo ln -s /usr/lib/jvm/jre1.7.0_07/lib/i386/libnpjp2.so ~/.mozilla/plugins/ Confirm that the JRE has been successful by using the official oracle website.
