Setting brightness at Ubuntu startup

In Ubuthu machines such as Thinkpad T520 every-time when we restart the computer the brightness level will be at its maximum and then we need to manually set the brightness to a comfortable level.

To solve this issue here I share a small script I have written.

First install xdotool

sudo apt-get install xdotool

This will allow you to change the brightness easily from the command line with out admin privileges.


Check whether the brightness is changing with the following command

xdotool key XF86MonBrightnessDown

Now we have to find the file where the brightness value is stored, try doing

cat /sys/class/backlight/acpi_video0/brightness

If you get an integer value then your good to proceed, else you have to find the appropriate file in your system. In that case check in /sys/class/


Adjust the brightness and find your desired brightness level using the above command E.g. 9


In this example I have used 9 as my brightness level change it according to you.

 
#!/bin/bash

myBrightness=9;
currentBrightness=`cat /sys/class/backlight/acpi_video0/brightness`;
count=$(( $currentBrightness - $myBrightness )) ;
while [ $count -gt 0 ]
do
     xdotool key XF86MonBrightnessDown
     let  count=$(($count-1));
done

Save this as brightness.sh


Then make this file to be an executable, by running

chmod +x brightness.sh

Finally open the "Startup Applications" click Add and add the following

Name :<appropriate name>
Command:/<path to file from root>/brightness.sh
Comment:<appropriate comment>

How to install Java Cryptography Extension (JCE) unlimited strength jurisdiction policy files

How to over come "org.apache.xml.security.encryption.XMLEncryptionException: Illegal key size or default parameters" or "java.security.InvalidKeyException:illegal Key Size" error when invoking secured services

These "org.apache.xml.security.encryption.XMLEncryptionException: Illegal key size or default parameters" or "java.security.InvalidKeyException:illegal Key Size" error usually occurs when we try to invoke a web services in a secured manner and your JVM is not provisioned for Java unlimited security jurisdiction.


To provision for the Java unlimited security jurisdiction we have to install Java Cryptography Extension (JCE) unlimited strength jurisdiction policy files.


How to Install JCE

1. Go to the Oracle Java SE download page http://www.oracle.com/technetwork/java/javase/downloads/index.html
2. Scroll down ... Under "Additional Resources" section you will find "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy File"
3. Download the version that matches your installed JVM E.g. UnlimitedJCEPolicyJDK7.zip
4. Unzip the downloaded zip 
5. Copy local_policy.jar and US_export_policy.jar to the $JAVA_HOME/jre/lib/security (Note: these jars will be already there so you have to overwrite them)
6. Then restart your application to get rid of this exception.