The _khAttAm_ blog

Posts Tagged ‘Linux’

I am building a Java Applet which needs to connect to foreign host to operate. I created it and it runs good on OpenJDK Runtime Environment (IcedTea6 1.8pre) installed on my Ubuntu 10.04 Lucid Lynx Beta. But it does not run with Sun Java Runtime Environment 1.6.0_18 on Windows. I don’t know if it also does not work with Sun JRE in Linux. Also, as far as I know, OpenJDK/OpenJRE for Windows does not exist.

The applet shows somewhat this kind of when run in Windows under Sun JRE:

1

java.security.AccessControlException: access denied (java.net.SocketPermission host connect,resolve)

and the page just stalls.

When I searched for help on the internet, I discovered that unsigned files do not run in Windows. So, I needed to sign it. The Certificate can cost at least a couple of hundred dollars for a month. If you are using it for commercial purposes, I advice you to buy a certificate. However, I just wanted my code to run in Windows and to do that I bundled the code inside a Jar file (I was just using the class file i.e. code=”Classname.class”. Now I need to use code=”Classname” archive=”JarName.jar” for applet in the HTML file.). So I am sharing what I did to make it run.

After building the Jar File (Netbeans IDE that I am using builds the Jar file automatically inside the dist sub-directory of the Project directory), I used the command

1

keytool -genkey

and entered the details. You can choose your own password for keystore. You can either use the same password for key password or choose a different one. Now a keyfile named .keystote is created in the home directory. I need to certify the key. Since I have not purchased a security certificate, I needed to certify it myself using the following command:

1

keytool -selfcert

. Now a key named mykey is created for me to use. This should only be done once.

Now, I changed my directory to the dist directory and executed the following command to sign a MyJarApplet.jar:

1

jarsigner -storepass KeySorePassword -keypass KeyPassPassword MyJarApplet.jar mykey

Here KeyStorePassword is the password used while creating the keystore and KeyPassPassword is the password used in the key mykey.

Now, the applet asks for authentication instead of showing nothing at all in Windows too.

Hope this helps.

References:
http://www-personal.umich.edu/~lsiden/tutorials/signed-applet/signed-applet.html
http://java.sun.com/j2se/1.4.2/docs/tooldocs/solaris/jarsigner.html
http://java.sun.com/j2se/1.4.2/docs/tooldocs/solaris/keytool.html

I am using Ubuntu 10.04 Lucid Lynx Alpha. I have a dsl connection (WiZoom, Wireless via ubnt but wired to my PC) from Worldlink Pvt. Ltd., Nepal. I need to connect via pppoe. I occasionally keep my PC to download overnight while I sleep or even when I am away. It works well with torrents (with deluge as my torrent client, I haven’t used transmission torrent client much) but sometimes it disconnects from the internet. So, I had to configure it to auto re-connect on disconnect. It should also connect on logon. Since network manager does not meet my requirements, Read the rest of this entry »

OpenShot is one of the best non-linear video editors coming up for Linux. You can install development version of OpenShot by adding ppa:openshot.developers/ppa to Synaptic>Settings>Repositories>Other Software>Add. Then, it can simply be installed from Synaptic Package Manager.

Docky is a great dock for Linux and is based on Gnome-do.

Read the rest of this entry »

As you know, Linuxmint is based on Ubuntu. So I thought, it might be possible to take Ubuntu as a base and turn it to Linuxmint with available Linuxmint software. Thats what I did.

I used Ubuntu Karmic Koala and turned it into Linuxmint Helena. You might use other Ubuntu base and turn it to respective Linuxmint distro, but you may need to follow different (yet similar) steps. Here is how I did it. Read the rest of this entry »

I want to build my college project on J2ME platform. I use Ubuntu and want to use NetBeans as my IDE.

I just installed netbeans, Sun Java Wireless Toolkit for CLDC and Mobility pack for netbeans. Here is how I did it. Read the rest of this entry »

I am using Ubuntu 9.10 Karmic Koala on my Desktop with Firefox 3.5 as my primary browser. Recently I was facing problems playing online media (streaming mp3s, non-flash) including FM from my own page on Firefox. Read the rest of this entry »

Here is how I installed Linux Mint Menu in Ubuntu 9.04 Jaunty Jackalope. I downloaded the following packages from the Linux Mint Repo which can be found here:
mintinstall
mint-info
mintsystem
mintmenu Read the rest of this entry »

If you are outside of the country or somewhere where you cannot listen to these FMs or simply want to waste your bandwidth, you can listen to them online, LIVE.

Here you will find links to Kantipur FM, Hits FM, Maitri FM, Nepal FM and Ujyalo FM:
http://www.khattam.info/fm (fixed)

However, you may like to listen to them with your favourite media player (VLC, what else). This can be possible if you have VLC installed. You will just need to download this small file and extract it somewhere. Then you may open those with VLC and listen to them.

In Ubuntu Jaunty Jackalope, I was unable to listen to Kantipur FM from their site, but am able to play the pls with VLC and Totem Media Player.

Goto FM Page at:
http://www.khattam.info/fm

Back in the days of 2005, I did not use Linux because it did not support my cheap PCTEL HSP56 Dial-up modem. Now, I do not use Windows Vista because it does not support my cheap Telson Electronics CDMA 1x USB Wireless Modem. Sorry for my poor choice of internet (both in 2005 and now) because I live in rural area of Nepal and we don’t have a choice. Read the rest of this entry »