In 2012, following the release of the much anticipated Raspberry Pi, my colleague Steve couldn’t resist getting JBoss EAP 6 to run on it, which he managed with
minimal effort! Not to be outdone, I’ve been inspired by the release of Ubuntu Touch – Canonical’s offering for mobile devices. Mark
Shuttleworth’s trailer videos
for the upcoming OS gave me a lot to
be excited about; I’ve long been wondering what could be possible if only I
could unlock the power of the computer I have in my pocket. Android is (at
the moment) my favourite mobile OS, but it’s always disappointed me a little
that there was no way to get Java running on it since it lacks necessary packages so when Ubuntu Touch was
announced, it finally seemed that there was a New Hope!

How is it
done?

Surprisingly
easily, once you know the correct steps.

Installing
Ubuntu on the Galaxy Nexus
is as easy as a single command, provided
you’ve already unlocked the bootloader. The installation process took a while –
around 30 minutes I think. In any case, it was far too long for a keen early
adopter to just sit around waiting! To fill my time, I downloaded the latest
Java SE embedded from Oracle (a painful mistake) and the latest promoted build
of Glassfish 4. (If you’re going to be an early adopter, you may as well do it
right.)

Ubuntu
installs itself very differently to how I expected and, being unfamiliar with
Android administration, there was a bit of a learning curve! Using the Ubuntu
SDK’s QT creator IDE, you can easily start an SSH session to your phone, once
you have wifi configured. I expected the terminal to be limited to some degree,
but what I didn’t expect was for it to lie to me!

After
connecting, a quick pwd tells me I’m in the /home/phablet directory (phablet
being the default user in Ubuntu Touch). The “phablet” user has limited
permissions and I quickly found I was unable to switch to the root user. I’m an
impatient man at the best of times, so rather than try to spend time fixing
that, I simply used the Android Developer Bridge (adb) that QT uses to connect
to the device. A couple of further pwds in various directories told me that
Ubuntu actually creates /data/ubuntu and uses that directory as root, so
although the “phablet” user couldn’t see outside of it to the Android files,
the root ADB user could!

Installing
Java

Installing
Java was not a fun task. I tried various ways of transferring the downloaded
file over to the phone using any method I could think of which would work on a
full terminal. Finally, I resorted to ADB once more, using the push command. I then quickly found out
that the terminal was powered by BusyBox and it simply refused to run certain
packages. (At this point, I suspected a full conspiracy towards my failure by
my phone and Ubuntu desktop.)

I am
nothing if not stubborn, however, and, remembering that OpenJDK 7 is certified
for ARM chipsets, I just tried to run apt-get on the right package from QT
which, to my surprise, worked first time!

[email protected]:~$ java -version

java -version

java version “1.7.0_07″

OpenJDK Runtime Environment (IcedTea7 2.3.2)
(7u7-2.3.2a-1ubuntu1)

OpenJDK Zero VM (build 22.0-b10, mixed mode)

Installing
Glassfish 4

I wasn’t
expecting much success after the trials of getting Java to run in an
environment that was so foreign to me, but I had a go anyway. After getting the latest promoted build of Glassfish 4 from the Aquarium,
I pushed the .zip over to the device with ADB again. After unzipping, I tried
to start the domain: bin/asadmin start-domain domain1

Nothing.

BusyBox
refused to execute asadmin (I ran chmod 755 just to be sure). Since I’d spent
the best part of the afternoon on trying to get this to work, in desperation, I
thought I would move the installation directory to /home/phablet and try to run
the command over SSH, rather than as root over ADB.

I ran the
same command and, to my surprise, Glassfish started to load. Surprise quickly
turned to horror when I realised that I was running full Glassfish on full Java
7 without changing any heap settings!

After
about 2 minutes of waiting with bated breath, the command returned that it had
started successfully. I could hardly believe it, so I went to the admin console
to check:

Not bad
for an afternoon’s work! Now all that’s left is to configure it!

All in
all, Ubuntu Touch is certainly not ready for the public, but I’m very impressed
with Unity as a smartphone interface and the power of having a full linux
distribution in your pocket.

This article is a re-post from: http://blog.c2b2.co.uk/2013/03/a-smartphone-as-jee-server-glassfish-on.html 

(Note: Opinions expressed in this article and its replies are the opinions of their respective authors and not those of DZone, Inc.)

Ubuntu VPS Hosting via A Smartphone as a Java EE Server: Glassfish 4 on Ubuntu Touch.