CodeMarvels – Page 20 – All's the Code !

Select the required package from here – http://www.oracle.com/technetwork/java/javase/downloads/index.html. Download the jdk-[version].bin file from the downloads page.
Make the downloaded file runnable; Eg – sudo chmod +x jdk-6u32-linux-x64.bin
Run this file; Eg- sudo ./jdk-6u32-linux-x64.bin
Move the newly created folder to /usr/lib/jvm/. Eg – sudo mv jdk1.6.0_32 /usr/lib/jvm/ (Optionally change the user of this folder to yourselves)

Add the newly added jdk to known java command option –


sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.6.0_32/bin/java" 1
sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.6.0_32/bin/javac" 1
sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jdk1.6.0_32/bin/javaws" 1

Choose the new java, javac and javaws by running commands-

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

Run java -version to verify installation. Cheers!

Notes/Technology

Eclipse Compilation error: [function/type] is not accessible due to restriction on required library … rt.jar

Posted on May 26, 2012 by Kj / 0 Comment

Problem : Eclipse gives the error – “[function/type] is not accessible due to restriction on required library … rt.jar” when building a project.

Reason: Project classpath (in the build path) is refers to JRE in place of the JDK in which the Project is configured to work with.

Fix: Go to Java Build Path > Libraries, choose JRE System Library, click Edit button. From the dialog choose Alternate JRE and choose the required JDK.

Notes/Technology

Ubuntu Error: Unable to lock the administration directory (/var/lib/dpkg/)

Posted on May 25, 2012 by Kj / 0 Comment

Problem: Ubuntu gives error “Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?” when using apt-get.

Reason: Another apt-get update working or Update manager checking for updates.

Fix: Close Update manager/ wait of current apt-get update to finish, and try again.

Notes/Technology

Create Shortcut / launcher on Desktop in Ubuntu 12.04

Posted on May 21, 2012 by Kj / 2 Comments

To create a shortcut to an application or location on the desktop (Ubuntu 12+), on terminal run –

Method 1: Installing Gnome Panel

if a shortcut is being created for the first time,
```
sudo apt-get install gnome-panel
```
, else directly do step 2.

gnome-desktop-item-edit ~/Desktop/ --create-new

In the launcher-creation window choose the type and location of the target. Click OK.

Method 2: For application shortcuts only

If shortcut to an installed application is to be created –

Go to Home Folder –> File System –> usr –> share –> applications.
Right click your favourite icon, choose Copy To –> Desktop

(from mhdizam’s comment, verified working)

Notes/Technology

Add a folder to left side pane of Nautilus file manager in Ubuntu

Posted on May 21, 2012 by Kj / 0 Comment

To add a folder to favorites in left tab of nautilus –

Go the required folder.
On title bar (at the top of desktop), go to and click Bookmarks => Add Bookmark.

Miscellaneous

How to record from sound card on Ubuntu ?

Posted on May 14, 2012 by Kj / 2 Comments

Given below is how we can record any streamed audio from sound card :

Install PulseAudio Volume Control from Ubuntu Software center.
Open PulseAudio volume control from Dash home.
Go to “Input Devices” Tab.
In the dropdown “Show” (towards bottom of the pane), select “All Input Devices“.
Set Monitor of Built-in Audio Analog Stereo as default fall back option (by clicking the green icon above it).
Close the volume control.
Open Sound Recorder from Dash. This should now record (only the) sounds played in the computer. You may choose “CD quality MP3” from the “Record as” drop down if you want to store the output as mp3s.

Note – Sound recorder is buggy and doesn’t show output formats in Ubuntu 13x. Audicity is a good alternative to use in such cases.

Notes/Technology

Ubuntu – Unable to resolve host error after a VPN session

Posted on May 12, 2012 by Kj / 0 Comment

Problem: Ubuntu unable to resolve hosts after a disrupted VPN session.

Reason: The DNS server not reset to normal from that of the VPN network.

Fix: On terminal, do –

sudo vi /etc/resolv.conf
Remove the “dns domain” and “dns server” lines from this file.
Save and close the file.
Restart browser or the app which needs to connect to internet.

Notes/Technology

Override certificate error in Cisco AnyConnect Client on Ubuntu 12.04 64 bit

Posted on May 9, 2012 by Kj / 6 Comments

Problem: Cisco Anyconnect client does not give an option to override the “invalid certificate error” and go ahead using the current certificate of the server.

Reason: The current libraries used by Anyconnect client does not support this feature.

Fix: Add libraries from Firefox, as below:

If firefox is not installed, install firefox from Ubuntu Software Center.
On terminal run: sudo cp /usr/lib/firefox/lib*.so /opt/cisco/vpn/lib/
Restart Anyconnect client and connect to required host. The certificate acceptance prompt should appear now.