Java / Ubuntu blog

Give your tomcat terminal a title

2010-11-24T16:42:00.000+10:00

Just put the following line in your bash script that you use to run tomcat...

echo -ne "\033]0;Tomcat_name\007"

Enjoy!

Fixed broken compiz wallpaper plugin in ubuntu 10.10

2010-11-05T22:44:00.002+10:00

As suggested in Bug #629391, rebuilding compiz with the fixed code worked for me.

Replacing the files in /usr/lib/compiz with the recompiled ones did the trick.

You can use my files (http://www.filefactory.com/file/b42294h/n/unzip_these_in_usr_lib_compiz.zip) if you are running a 64 bit ubuntu 10.10.

Enjoy!

Remove oracle from the GDM login screen

2010-10-10T13:45:00.000+10:00

Don't want to see oracle in the GDM login screen list?

1. Stop oracle: sudo /etc/init.d/oracle-xe stop

2. Remove from the GDM login screen list: sudo usermod -u 999 oracle

3. Start oralce: sudo /etc/init.d/oracle-xe start

Done

Can't see sun java in Synaptic?

2010-10-09T22:00:00.000+10:00

Enable lucid partner in software sources

And its there

Enjoy!

Fixed headphone sound problem for my dell suidio 16 xps running ubuntu 10.04

2010-09-11T22:04:00.001+10:00

Headphone sound wasn't working in my dell studio 16 xps with ubuntu 10.04.

Adding options snd-hda-intel model=dell-m6 at the end of /etc/modprobe.d/alsa-base.conf sovled this issue.

Extreame VirtualBoxing: Running Windows 7 HOST from VirtualBox as a guest on Ubuntu 10.04 linux host

2010-08-28T17:12:00.003+10:00

No its not a typo.

This is the extremest VirtualBoxing I have ever done.

In my dual boot Windows 7 + Ubuntu 10.04, I could successfully run the Windows 7 from an instance of VirtualBox that I have installed in my Ubuntu 10.04.

Just followed this VirtualBox guru Aaron burner in his post

Force install 32 bit oracle xe in 64 bit Ubuntu

2010-08-21T23:17:00.001+10:00

Force install libaio_0.3.104-1_i386.deb first

Then force install oracle-xe_10.2.0.1-1.1_i386.deb

Thats it. Enjoy!

Customize plymouth script plugin to use a different image as a plymouth splash in ubuntu 10.04

2010-08-20T22:35:00.001+10:00

Install plymouth-theme-script

Open the script file with sudo

Add the following lines and save

bg.png is the image file

Now select the script plugin as the default one

And finally run sudo update-initramfs -u and restart

Enjoy!

Plymouth wont showup boot splash (blank screen) and GDM Login starts before Plymouth in Ubuntu 10.04

2010-08-14T22:48:00.001+10:00

Using the initramfs to start plymouth as a critical step worked for me

Run the following commands with sudo...

echo FRAMEBUFFER=y > /etc/initramfs-tools/conf.d/splash

update-initramfs -u

How to change Grub2's splash image in Ubuntu 9.10 - the Karmic Koala

2009-11-01T23:51:00.006+10:00

Follow the steps bellow to change Grub2's splash image in Ubuntu 9.10 - the Karmic Koala

(Step 1) Open nautilus as root:

(unless you want to run dozens of sudo commands)

Open a terminal and run sudo nautilus

(Step 2) Copy the image to /usr/share/images/desktop-base:

Copy your grub2 image (I am using a 640x480 RGB PNG) to /usr/share/images/desktop-base

(Step 3) Edit the "05_debian_theme" file:

Go to /etc/grub.d and open 05_debian_theme file to Display

Edit the following line

for i in {/boot/grub,/usr/share/images/desktop-base}/moreblue-orbit-grub.{png,tga} ; do

The highlighted bit in yellow should be your image file name (minus the extension).

Save and exit.

This should do the trick.

Enjoy!

How to disable the login screen user list in Ubuntu 9.10 - the Karmic Koala

2009-11-01T22:38:00.001+10:00

To disable the login screen user list in Ubuntu 9.10 - the Karmic Koala...

Open a terminal

And run the following command

sudo gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --type bool --set /apps/gdm/simple-greeter/disable_user_list true

This should do the job.

Enjoy!

Chnage splash and login theme in Ubuntu 9.10 - the Karmic Koala

2009-11-01T18:50:00.007+10:00

Ubuntu 9.10 - the Karmic Koala is available now and ready for you to hack into.

Its no longer usplash and GDM, its xsplash now.

So to change the default splash and login screen (the one that is shown while Ubuntu loads and while you log in) follow the steps below...

(Step 1) open nautilus as root:

Open a terminal

and run sudo nautilus

(Step 2) Rename the default files:

Go to /usr/share/images/xsplash and rename all the bg_*x*.jpg files as bg_*x*.jpg.bak files, where * x* are the resolutions of the images. Just to keep the original ones as backups.

(Step 3) Save the image you like in different resolutions:

Use GIMP to save the image that you like with the bg_*x*.jpg name format, and keep doing it for the rest of the bg_*x*.jpg files.

Also make sure you scale each image into it's proper resolution.

Copy them all in the /usr/share/images/xsplash.

And thats it. Next tiem you restart the system it will use your image.

Enjoy!

Fine tune your desktop background for using different background images in your compiz cube

2009-10-01T01:30:00.002+10:00

This is a continuation of the previous post "How to use different backgrounds for different compiz cube virtual desktops".

If you are already using different background images for your compiz cube and also if you are not happy because you can see a different image when Ubuntu first loads your desktop and then suddenly changes to the one that you have chosen then follow the steps bellow to fine tune...

(Step 1) Change the background image that Nautilus draws:

System -> Preferences -> Appearance

And then in the background tab change the background image to the one that your compiz cube has in its first virtual desktop. Also select the best matching settings (like Scaled or Scaled and Corp etc) for it as you have done in the CompizConfig Settings Manager.

(Step 2) Select a solid color for the black blank screen:

Also if you select a solid color in the same tab, the black blank screen that appears in-between your GDM login screen and the desktop image, the screen will change into the color that you have selected.

Just play around with it a bit and you will be able to figure out the differences.

Enjoy compiz!

Using NX Free Edition (not the Remote Desktop Viewer) to remote desktop from Ubuntu to Ubuntu

2009-09-13T01:19:00.001+10:00

The default for remote desktoping from Ubuntu to Ubuntu is the Remote Desktop Viewer which seems painfully slow to me. So just started trying NoMachine's NX Free Edition for Linux which looks promising.

Using:

1. Two Ubuntu Jaunty v9.04 boxes (64 bit) over a WLAN

2. nxclient v3.3.0-6

3. nxnode v3.3.0-22

4. nxserver v3.3.0-27

Also installed openssh-server as this is required for NX

(Step 1) Get the appropriate packages from NoMachine's download page:

I am using 64 bit Ubuntu Jaunty v9.04, so I got the followings...

1. nxclient_3.3.0-6_x86_64.deb

2. nxnode_3.3.0-22_x86_64.deb

3. nxserver_3.3.0-27_x86_64.deb

(Step 2) Install the NX packages:

Now to install the downloaded packages just double click on each of them and install (follow the sequence nxclient -> nxnode -> nxserver for dependency satisfaction).

These need to be installed on each of your boxes in which you want to use the NX services.

(Step 3) Run NX Client for Linux to remote desktop:

Applications -> Internet -> NX Client for Linux -> NX Client for Linux

Since this is the first time we are using NX, it will take us through the NX Connection Wizard. Click on Next in the first screen

And put the details for your remote Ubuntu box on the next

Select the ones that are appropriate for you in the next one

Finally click on Finish

And now in the login window put the credentials and click on Login

Enjoy your remote desktop with NX!

How to use different backgrounds for different compiz cube virtual desktops

2009-09-11T22:01:00.001+10:00

(Step 1) Install compiz and compizconfig-settings-manager:

System -> Administration -> Synaptic Package Manager

Select compiz and compizconfig-settings-manager -> Mark for Installation -> Apply

(Step 2) Configure nautilus NOT TO show your desktop (by default nautilus is responsible for showing your desktop):

Alt + F2 -> Type gconf-editor -> Run

Select apps -> nautilus -> preferences from the left pane of the Gnome Configuration Editor and uncheck show_desktop

(Step 3) Configure compiz to show the cube desktops with different backgrounds:

System -> Preferences -> CompizConfig Settings Manager

General -> General Options -> Select Desktop Size tab

Set the Horizontal Virtual Size = 4 and Vertical Virtual Size = 1

Go Back

Select Desktop from the left pane and check Desktop Cube and Rotate Cube from the right pane

Now select Utility from the left pane and check Wallpaper from the right pane

Now click on Wallpaper and click on the New button to select a background image for your first virtual desktop. Continue with the same process to add four different background images.

Its ready now.

(Step 4) Check if its working:

To check that your Cube has different backgrounds go like CTRL + ALT + -> (right arrow key) to rotate your cube on the right.

How is that?

Enjoy!

org.apache.maven.lifecycle.LifecycleExecutionException: Error installing artifact's metadata: Error installing metadata: Error updating group repos...

2009-07-23T08:40:00.001+10:00

First of all, don't delete the whole maven repository! We don't have to (I hope!).

Maven was complaining with...

org.apache.maven.lifecycle.LifecycleExecutionException: Error installing artifact's metadata: Error installing metadata: Error updating group repository metadata.

Now some forum recommended to delete the whole repository. I didn't like that.

Digging more into the error you can see that maven was trying to install/update (Error installing artifact's metadata: Error installing metadata: Error updating group repository metadata.) some metadata. Since I hadn't add any new dependency, I guessed the only artifact it can talk about is either my project's artifact or something of its own.

And guess what? Found an artifact in my maven repository that matches exactly with my project. Got rid of that and...

The problem is solved!

Install and run VMware 2.0.1 server with 64 bit v2.6.30 Linux kernel

2009-07-17T12:10:00.001+10:00

I am using the followings...

64 bit Ubuntu with kernel v2.6.30
64 bit version of VMware server 2.0.1 (VMware-server-2.0.1-156745.x86_64.tar.gz),
A patch file to fix the vmware-config.pl (vmware-config.pl.patch.txt : Ubuntu Community Documentation),
A patch file and a script file to run the whole module fix process for kernel v2.6.30 (vmware-server.2.0.1_x64-modules-2.6.30-fix.patch, vmware-server.2.0.1_x64-modules-2.6.30-fix.sh : Thanks to Michele).

Following are the steps that I took...

Extract all the contents (the whole vmware-server-distrib folder) from the VMware-server-2.0.1-156745.x86_64.tar.gz.
Copy both the patch files (vmware-config.pl.patch.txt, vmware-server.2.0.1_x64-modules-2.6.30-fix.patch) and the script file (vmware-server.2.0.1_x64-modules-2.6.30-fix.sh) in the same folder where you have extracted vmware-server-distrib.
Patch the vmware-config.pl with the sudo patch vmware-server-distrib/bin/vmware-config.pl vmware-config.pl.patch.txt command.
Now install VMware server. I accepted all the defaults while installing. (make sure you skip the last configuration part).
Now run the script to fix the modules.
After it finishes configure VMware server (run sudo vmware-config.pl).
When it asks for gcc, say yes.
For the VSOCK say yes.
Add your user name as the administrator.
For the rest I have just selected the defaults.
And that's it.

Enjoy VMware server.

java.lang.NoClassDefFound Error: org/springframework/ldap/core/support/BaseLdapPathContextSource

2009-07-16T15:27:00.001+10:00

While working with my Spring MVC and LDAP (Apache DS, OpenDS and Active Directory) project I was getting java.lang.NoClassDefFound Error: org/springframework/ldap/core/support/BaseLdapPathContextSource

Adding the Spring LDAP jar solved the problem.

I am building with Maven2, so this is what I had to add

For Ant add spring-ldap.jar

Java ME projects with Eclipse Galileo Pulsar (or NetBeans) and WTK 2.5.2 in 64 bit Ubuntu

2009-07-10T17:44:00.001+10:00

With Eclipse:

The new Eclipse Galileo Pulsar has a 64 bit version for Ubuntu but the WTK that comes for Linux is a 32 bit one and is version 2.5.2 (the latest version 3 only comes for Windows!).

So how do you work with Eclipse Pulsar on a 64 bit Linux box?

I am using

64 bit Ubuntu Jaunty 9.04 with Linux kernel 2.6.30 and Gnome
64 bit Eclipse Galileo IDE for Java EE developers (you can also use the Eclipse Pulsar for Mobile Java Developers but I prefer to use plugins in the same IDE)
32 bit WTK 2.5.2 (sun_java_wireless_toolkit-2.5.2_01-linuxi486)
32 bit JDK 1.6 (jdk-6u14-linux-i586). I have different JDKs in my box (different versions and from different vendors) and I will use this 32 bit one only for Java ME development.

Following are the steps that I took and it works for me...

Install Eclipse Galileo (with Pulsar and MTJ plugins or the Pulsar version, whichever you like)
Install a 32 bit JDK (the current one from Sun is jdk-6u14-linux-i586)
Install a 32 bit WTK (the current from Sun is sun_java_wireless_toolkit-2.5.2_01-linuxi486). While installing the WTK, the installer will ask for a JRE/JDK location. Make sure to point it to the 32 bit JDK one that you have installed in step 2.
Configure JRE in Eclipse preferences. In Eclipse go like Window -> Preferences -> Java -> Installed JREs and then just add the new 32 bit JDK and select it.
Also don't forget to configure Java ME Configuration for your project.
Now create, run and enjoy your new Java ME project.

There will be an error/warning message (I have got it in mine) from Gtk...

Gtk-Message: Failed to load module "canberra-gtk-module": /usr/lib/gtk-2.0/modules/libcanberra-gtk-module.so: wrong ELF class: ELFCLASS64

I have tried to run 32 bit Eclipse with the 32 bit JDK and Gtk still complains the same way, so its not Eclipse, JDK or WTK its actually Gtk complaining about us running 32 bit staff.

With NetBeans:

To make it working with NetBeans follow the steps bellow...

Install 64 bit NetBeans (I am using version 6.7)
Follow the same steps 2 and 3 mentioned above to install the 32 bit JDK and WTK.
Open the /etc/netbeans.conf file and change the netbeans_jdkhome to point to the 32 bit JDK.
Also add the 32 bit JDK and WTK in the Java Platforms (Tools -> Java Platforms) and remove others.
Now you should be able to run and enjoy your Java ME projects in NetBeans as well.

GTK will complain the same way about the ELF class

Gtk-Message: Failed to load module "canberra-gtk-module": /usr/lib/gtk-2.0/modules/libcanberra-gtk-module.so: wrong ELF class: ELFCLASS64

Upgrading the Linux kernel in Ubuntu

2009-06-27T01:43:00.001+10:00

I have just upgraded my linux kernel to 2.6.30 for my jaunty box.

Following are the steps...

1) Downloaded the packages (v2.6.30 in my case) from http://kernel.ubuntu.com/~kernel-ppa/mainline/

Needed the followings for my 64 bit jaunty...

a) linux-headers-2.6.30-020630-generic_2.6.30-020630_amd64.deb

b) linux-headers-2.6.30-020630_2.6.30-020630_all.deb

c) linux-image-2.6.30-020630-generic_2.6.30-020630_amd64.deb

2) cded to the directory where the files are and ran the following command...

sudo dpkg -i linux*2.6.30*.deb

3) And rebooted when done...

sudo reboot now

Thats it.

ClassNotFoundException: org.hibernate.hql.ast.HqlToken... while deploying hibernate application on WebLogic.

2009-06-26T00:30:00.001+10:00

I was having the following exception while deploying my Spring-Hibernate application on WebLogic 1o.3 server.

ClassNotFoundException: org.hibernate.hql.ast.HqlToken...

Eventually I found that its not my application but the ANTLR. WebLogic tries to use its own version of ANTLR while Hibernate needs some other (antlr-2.7.6.jar in my case).

The way to fix the problem is to override WebLogic's one. And adding the following lines in the setDomainEnv.sh (in my Ubuntu 9.04 box) did the job.

Following are the origonal lines that I have commented out...

#CLASSPATH="${PRE_CLASSPATH}${CLASSPATHSEP}${WEBLOGIC_CLASSPATH}${CLASSPATHSEP}${POST_CLASSPATH}${CLASSPATHSEP}${WLP_POST_CLASSPATH}"

#export CLASSPATH

And following are the lines that I have added...

ANTLR_PATH="${WL_HOME}/hibernate/antlr-2.7.6.jar"

CLASSPATH="${ANTLR_PATH}${CLASSPATHSEP}${PRE_CLASSPATH}${CLASSPATHSEP}${WEBLOGIC_CLASSPATH}${CLASSPATHSEP}${POST_CLASSPATH}${CLASSPATHSEP}${WLP_POST_CLASSPATH}"

export CLASSPATH

And then after restarting the server, redeploying the application worked like magic.

Selenium tests with firefox on a ubuntu box

2009-06-24T02:49:00.001+10:00

I was having difficulties running selenium core tests for my maven project on a jaunty (ubuntu 9.04) box with firefox (3.0.11).

Eventually found a workaround. If we run firefox with a different profile and set its proxy as localhost:4444, it works.

Following are the steps that I took...

1. Create a firefox profile (here is a very nice tutorial about firefox profile)

2. Set firefox proxy

3. Mention the profile from my code.

*custom /usr/lib/firefox-3.0.11/firefox -p selenium-test-profile

And thats it.

How to stop Jaunty (Ubuntu 9.04) beeping while shut down/restart

2009-06-23T02:08:00.001+10:00

Just unload the PC speaker module.

Run the following command in a terminal...

sudo rmmod pcspkr

Try shut down/restart now. If this removes the beep, then continue with the following...

sudo cp /etc/modprobe.d/blacklist.conf /etc/modprobe.d/blacklist.conf.bak

Add the following line to /etc/modprobe.d/blacklist.conf to prevent the module from ever loading

blacklist pcspkr

This should do the job. Worked for me!

Oracle 10g XE connection problem from Java applications

2009-05-27T02:48:00.001+10:00

java.sql.SQLException: Listener refused the connection with the following error: ORA-12519, TNS:no appropriate service handler found The Connection descriptor used by the client was: localhost:1521:XE

To fix the above connection limitation in Oracle 10g XE run the following sql command...

ALTER SYSTEM SET PROCESSES=150 SCOPE=SPFILE

Install ojdbc14.jar in your local maven repository

2009-05-11T23:23:00.001+10:00

To install ojdbc14.jar in your local maven repository use the following command...

mvn -e "install:install-file" -Dfile=ojdbc14.jar -DgroupId=com.oracle -DartifactId=ojdbc14 -Dversion=10.2.0.4.0 -Dpackaging=jar -DgeneratePom=true

Setting JAVA_HOME, M2_HOME and M2 environment variables in Linux (Ubuntu)

2009-04-17T23:36:00.001+10:00

Open your .profile file using a text editor like gedit and add the following lines at the end

JAVA_HOME="your jdk directory path"

M2_HOME="your maven directory path"

M2="$M2_HOME/bin"

export JAVA_HOME

export M2_HOME

export M2

export PATH=$M2:$PATH