Table of Contents
Introduction
This page is based on experience of setting up Java 8 on Ubuntu 14.04. Much of it may be applicable to other Java versions and distros.
Architecture
First we check which architecture we are running on.
Open a terminal and type the command :
arch
The output could be i686 or i386 for a 32 bits system or x86_64 for a 64 bits system.
Environment
Your environment could already have an installation or not.
Open a terminal and run the following command :
user@machine:~$ java -version java version "1.8.0_25" Java(TM) SE Runtime Environment (build 1.8.0_25-b17) Java HotSpot(TM) Server VM (build 25.25-b02, mixed mode)
In the previous output we can see that the command has been successfully executed. It gives us the default version.
Then run the following command :
user@machine:~$ update-java-alternatives -l java-1.6.0-openjdk-i386 1061 /usr/lib/jvm/java-1.6.0-openjdk-i386 java-1.7.0-openjdk-i386 1071 /usr/lib/jvm/java-1.7.0-openjdk-i386 java-1.8.0-openjdk-i386 1069 /usr/lib/jvm/java-1.8.0-openjdk-i386 java-8-openjdk-i386 1069 /usr/lib/jvm/java-8-openjdk-i386
The current installation shows that several JVM are installed.
Installation
Run the following commands in order to install or update the Open JDK 8. The idea is applicable to others JVM.
sudo add-apt-repository ppa:openjdk-r/ppa sudo apt-get update sudo apt-get install openjdk-8-jdk
Update Alternatives
if you have more than one Java versions installed on your system.
update-alternatives is a symbolic link management system for Linux.
Run the following command and select the desired jvm.
user@machine:~$ sudo update-alternatives --config java There are 3 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ------------------------------------------------------------ 0 /usr/lib/jvm/java-7-openjdk-i386/jre/bin/java 1071 auto mode 1 /usr/lib/jvm/java-6-openjdk-i386/jre/bin/java 1061 manual mode 2 /usr/lib/jvm/java-7-openjdk-i386/jre/bin/java 1071 manual mode * 3 /usr/lib/jvm/java-8-openjdk-i386/jre/bin/java 1069 manual mode Press enter to keep the current choice[*], or type selection number:
Set the default Java Compiler by running:
sudo update-alternatives --config javac
Set the default Java Web Start by running:
sudo update-alternatives --config javaws
In case your jvm is not recognized, you need to install it manually.
Run the following command:
sudo update-alternatives --install /usr/bin/java java /media/java-8-oracle 1071
Check if your added jvm has been processed by running:
user@machine:~$ update-alternatives --list java /media/java-8-oracle /usr/lib/jvm/java-8-openjdk-i386/jre/bin/java /usr/lib/jvm/java-8-oracle/jre/bin/java
Manual installation need to be applied to each jdk components. In this tutorial we described the process for java, javac and javaws however more components need to be updated.
Follow the next paragraph before manually add everything, most of the time update-java-alternatives completes the work.
Update Java Alternatives
However this first part doesn't solve all the default tools to use with the desired JVM.
update-java-alternatives is a program to update alternatives for jre/jdk installations.
The following command shows you if the tools use the JVM you want :
user@machine:~$ update-alternatives --get-selections | grep java appletviewer manual /usr/lib/jvm/java-8-openjdk-i386/bin/appletviewer extcheck manual /usr/lib/jvm/java-8-openjdk-i386/bin/extcheck idlj manual /usr/lib/jvm/java-8-openjdk-i386/bin/idlj itweb-settings auto /usr/lib/jvm/java-6-openjdk-i386/jre/bin/itweb-settings jar manual /usr/lib/jvm/java-8-openjdk-i386/bin/jar jarsigner manual /usr/lib/jvm/java-8-openjdk-i386/bin/jarsigner java manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/java javac manual /usr/lib/jvm/java-8-openjdk-i386/bin/javac javadoc manual /usr/lib/jvm/java-8-openjdk-i386/bin/javadoc javah manual /usr/lib/jvm/java-8-openjdk-i386/bin/javah javap manual /usr/lib/jvm/java-8-openjdk-i386/bin/javap javaws auto /usr/lib/jvm/java-6-openjdk-i386/jre/bin/javaws jcmd manual /usr/lib/jvm/java-8-openjdk-i386/bin/jcmd jconsole manual /usr/lib/jvm/java-8-openjdk-i386/bin/jconsole jdb manual /usr/lib/jvm/java-8-openjdk-i386/bin/jdb jdeps manual /usr/lib/jvm/java-8-openjdk-i386/bin/jdeps jexec manual /usr/lib/jvm/java-8-openjdk-i386/jre/lib/jexec jhat manual /usr/lib/jvm/java-8-openjdk-i386/bin/jhat jinfo manual /usr/lib/jvm/java-8-openjdk-i386/bin/jinfo jjs manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/jjs jmap manual /usr/lib/jvm/java-8-openjdk-i386/bin/jmap jps manual /usr/lib/jvm/java-8-openjdk-i386/bin/jps jrunscript manual /usr/lib/jvm/java-8-openjdk-i386/bin/jrunscript jsadebugd manual /usr/lib/jvm/java-8-openjdk-i386/bin/jsadebugd jstack manual /usr/lib/jvm/java-8-openjdk-i386/bin/jstack jstat manual /usr/lib/jvm/java-8-openjdk-i386/bin/jstat jstatd manual /usr/lib/jvm/java-8-openjdk-i386/bin/jstatd keytool manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/keytool lucli auto /usr/lib/liblucene2-java/lucli mozilla-javaplugin.so manual /usr/lib/jvm/java-8-openjdk-i386/jre/lib/i386/IcedTeaPlugin.so native2ascii manual /usr/lib/jvm/java-8-openjdk-i386/bin/native2ascii orbd manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/orbd pack200 manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/pack200 policytool manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/policytool rmic manual /usr/lib/jvm/java-8-openjdk-i386/bin/rmic rmid manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/rmid rmiregistry manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/rmiregistry schemagen manual /usr/lib/jvm/java-8-openjdk-i386/bin/schemagen serialver manual /usr/lib/jvm/java-8-openjdk-i386/bin/serialver servertool manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/servertool tnameserv manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/tnameserv unpack200 manual /usr/lib/jvm/java-8-openjdk-i386/jre/bin/unpack200 wsgen manual /usr/lib/jvm/java-8-openjdk-i386/bin/wsgen wsimport manual /usr/lib/jvm/java-8-openjdk-i386/bin/wsimport xjc manual /usr/lib/jvm/java-8-openjdk-i386/bin/xjc user@machine:~
if the tools are not using the needed JVM some extra step are required:
Run the following command :
sudo update-java-alternatives -s java-8-openjdk-i386
This command update the dependencies but can also complain about some missing components.
update-alternatives: error: no alternatives for mozilla-javaplugin.so. update-java-alternatives: plugin alternative does not exist: /usr/lib/jvm/java-8-openjdk-i386/jre/lib/i386/IcedTeaPlugin.so
Verification
To verify is everything is fine you can check the if the correct program are used.
Run the following command :
which java javac javaws
You could have an output like this
/usr/bin/java /usr/bin/javac /usr/bin/javaws
We can continue with the following command :
file `which java javac javaws`
We could have an output like this :
/usr/bin/java: symbolic link to `/etc/alternatives/java' /usr/bin/javac: symbolic link to `/etc/alternatives/javac' /usr/bin/javaws: symbolic link to `/etc/alternatives/javaws'
and finally resolve the next symbolic link :
file /etc/alternatives/java /etc/alternatives/javac /etc/alternatives/javaws
and we got :
/etc/alternatives/java: symbolic link to `/usr/lib/jvm/java-8-oracle/jre/bin/java' /etc/alternatives/javac: symbolic link to `/usr/lib/jvm/java-8-oracle/bin/javac' /etc/alternatives/javaws: symbolic link to `/usr/lib/jvm/java-8-oracle/jre/bin/javaws'
In this sample all the links are going to the correct place.
This assumes the "alternatives" system is working properly, which might not be the case, depending on how Java has been "messed up" in the past.
Mozilla Java Plugin
In this example the Mozilla plugin is missing. This is not a big problem if you don't want to use for security reason.
In case you want to install it, here is the procedure to get it. At the time we wrote this guide the icedtea-8-plugin is not available in the standard repository.
sudo add-apt-repository ppa:maarten-fonville/ppa sudo apt-get update sudo apt-get install icedtea-8-plugin
As we installed a new java component we need to re-run the 'update-java-alternatives' command:
sudo update-java-alternatives -s java-8-openjdk-i386
Some problem can happen depending the sequence and the way you try to achieve this task. I face some issues with missing or wrong symbolic link.
Here is the output of my /usr/lib/jvm directory :
user@machine:~$ cd /usr/lib/jvm user@machine:/usr/lib/jvm$ ls -al total 88 drwxr-xr-x 6 root root 4096 Apr 19 15:39 . drwxr-xr-x 210 root root 53248 Mar 31 07:41 .. lrwxrwxrwx 1 root root 23 Apr 19 15:39 default-java -> java-1.8.0-openjdk-i386 lrwxrwxrwx 1 root root 19 Mar 5 2013 java-1.6.0-openjdk-i386 -> java-6-openjdk-i386 -rw-r--r-- 1 root root 2345 Jan 26 23:05 .java-1.6.0-openjdk-i386.jinfo lrwxrwxrwx 1 root root 19 Apr 8 2014 java-1.7.0-openjdk-i386 -> java-7-openjdk-i386 -rw-r--r-- 1 root root 2396 Mar 24 16:46 .java-1.7.0-openjdk-i386.jinfo lrwxrwxrwx 1 root root 19 Jan 29 06:25 java-1.8.0-openjdk-i386 -> java-8-openjdk-i386 -rw-r--r-- 1 root root 2501 Jan 29 06:25 .java-1.8.0-openjdk-i386.jinfo drwxr-xr-x 3 root root 4096 Mar 12 2013 java-6-openjdk-common drwxr-xr-x 7 root root 4096 Feb 13 09:18 java-6-openjdk-i386 drwxr-xr-x 7 root root 4096 Mar 25 07:59 java-7-openjdk-i386 drwxr-xr-x 7 root root 4096 Apr 19 13:04 java-8-openjdk-i386 lrwxrwxrwx 1 root root 30 Apr 19 15:28 .java-8-openjdk-i386.jinfo -> .java-1.8.0-openjdk-i386.jinfo
The default-java should be linked with your desired JVM.
The command update-java-alternatives complained also with a missing .java-8-openjdk-i386.jinfo file. I created an appropriate link towards the existing .java-1.8.0-openjdk-i386.jinfo file.
Java Source
When I've installed the OpenJDK 8 I realized that the Java source code was not available. Usually below you default-java directory you should see a src.zip file. In my case the src.zip file was a reported broken link towards '../openjdk-8/src.zip'.
Run the following command :
sudo apt-get install openjdk-8-source
While installing a java component the command can give a few hints :
user@machine:~$ sudo apt-get install openjdk-8-source [sudo] password for user: Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: linux-headers-3.13.0-79 linux-headers-3.13.0-79-generic linux-image-3.13.0-79-generic linux-image-extra-3.13.0-79-generic Use 'apt-get autoremove' to remove them. The following extra packages will be installed: openjdk-8-jdk openjdk-8-jdk-headless openjdk-8-jre openjdk-8-jre-headless Suggested packages: openjdk-8-demo visualvm openjdk-8-jre-jamvm fonts-ipafont-gothic fonts-ipafont-mincho ttf-telugu-fonts ttf-oriya-fonts ttf-kannada-fonts ttf-bengali-fonts The following NEW packages will be installed: openjdk-8-jdk-headless openjdk-8-source The following packages will be upgraded: openjdk-8-jdk openjdk-8-jre openjdk-8-jre-headless 3 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. Need to get 81.2 MB of archives. After this operation, 52.1 MB of additional disk space will be used. Do you want to continue? [Y/n]
In that case an 'sudo apt-get autoremove' is suggested and additional packages are also suggested. We have also an idea of the openjdk-8-source estimated size of 52,1 MB. Once installed I got a new directory below my '/usr/lib/jvm' directory. 'openjdk-8' exists and contains the needed 'src.zip' file thus fixing the reported broken link.
Enjoy