Install Oracle JDK 7 on Ubuntu

Update: while the method below is still a possibility (and people running Linux are usually not afraid to go the extra mile to have their system running exactly as they want), there is of course a much, much simpler way to accomplish the same: using the PPA from the "WebUpd8" team, your Oracle JDK is installed and kept up-to-date in a breeze.

Just follow the instructions on https://launchpad.net/~webupd8team/+archive/ubuntu/java!

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Since I've been installing Java for development purposes a few times now on different machines running Ubuntu and had to look up how to do that each time (my attention span obviously is too short to remember properly), I've decided to make a blog entry out of it.

So the following steps will guide you through the process:

1) Download the JDK from Oracle
Go to the JDK download page and choose the version you need or want. You have to accept the agreement and you will want to choose the package for Linux in the compressed tarball format (Make sure you get the correct version corresponding to your Ubuntu installation; I got the 64-bits version, so that's jdk-[version]-linux-x64.tar.gz; for 32-bits you'd need the one with -i586 in the name).
At the time of this writing, the newest version was JDK7u5, but these guidelines should work on any 'modern' JDK.

Note: if you're interested in developing JavaFX, unlike the Windows and Mac OS packages, the Linux JDK doesn't contain the JavaFX SDK. You'll need to get a 'developer preview' here, and to be able to download it I had to log in with my (free) Oracle account.

2) Extract the package
You can use the file manager, right-click on the package and choose 'Extract here'.
Alternatively, if you insist on using the command line, use (assuming you're in the directory the package was downloaded to):

tar -xvf jdk-[version]-linux-x64.tar.gz

3) Move the extracted package to the right directory
The JDK should be moved to the place where all the libraries reside, so first you create a logical path and then you move the package:

sudo mkdir -p /usr/lib/jvm/jdk1.7.0

sudo mv jdk1.7.0_05/* /usr/lib/jvm/jdk1.7.0/

(You'll be prompted for your password to be able to perform the sudo commands.)

4) Enable the JDK
Now the system needs to be able to find the JDK, more specifically the binaries that can be run: the main Java laucher, the compiler and the Web Start launcher.

sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.7.0/bin/java" 1
sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.7.0/bin/javac" 1
sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jdk1.7.0/bin/javaws" 1

5) Make the new JDK the default choice - if necessary
If the JDK you just installed is the only one on your system, then this step is not required. If you're not working on a freshly installed machine, this will most likely not be the case, and you'll need to configure the settings so the new JDK is picked instead of the other ones.

sudo update-alternatives --config java

This will bring up an overview of the available alternatives, indicating the current default. Just enter the number that is printed in front of the launcher from the fresh install.
Rinse and repeat for the compiler and Web Start launcher:

sudo update-alternatives --config javac
sudo update-alternatives --config javaws

You can check whether all went well by retrieving the version of the Java installation:

java -version

and you should see something like:

java version "1.7.0_05"
Java(TM) SE Runtime Environment (build 1.7.0_05-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.1-b03, mixed mode)

And you're done!

Note: if you're getting a “No such file or directory” message instead of the Java version and you've made sure the symbolic links are correct and the files are there, chances are that you've installed a 32-bits JDK on a 64-bits OS. Remove the directory under /usr/lib/jvm/jdk1.7.0/ and start again from step 1, choosing the right package this time.

Customizing the JNDI name(s) of the JBoss 5.1 ConnectionFactory

Customizing the JNDI name(s) of the JBoss 5.1 ConnectionFactory takes the following steps:

- Change or add the binding name(s) in the [server]/deploy/messaging/connection-factories-service.xml file:

   
      jboss.messaging:service=ServerPeer
      jboss.messaging:service=Connector,transport=bisocket
      jboss.messaging:service=PostOffice

      
         
            /ConnectionFactory
            /XAConnectionFactory
            java:/ConnectionFactory
            java:/XAConnectionFactory
            /YOUR_JNDI_NAME_HERE
         
      
  

Same goes for the clustered connection factory (defined in the same file just under the other one).

- Only if necessary (i.e. changed in the above) adjust the corresponding reference in the JMS datasource file ([server]/deploy/messaging/jms-ds.xml, this is the original file referencing the standard java:/XAConnectionFactory reference):

   
      DefaultJMSProvider
      org.jboss.jms.jndi.JNDIProviderAdapter
      java:/XAConnectionFactory
      java:/XAConnectionFactory
      java:/XAConnectionFactory
   

Now you can use whatever name you want to bind the connection factory to from within your application!