A Noted Path by Theodore Nguyen-Cao

In the previous post, I described how to get your Java SDK installed on your machine. In this piece, I’ll lay out how to get your tomcat instance up and running.

Let’s setup our JAVA_HOME. While you can set this setting in many places, I decide to stick it in bash.bashrc.

My Java installation from apt-get put Java under /usr/lib/jvm/java-6-sun.

sudo vi /etc/bash.bashrc

Enter in:

# set JAVA_HOME environment variable
JAVA_HOME=/usr/lib/jvm/java-6-sun

Save and quit vi. Log out and log back into your console and you should be able to do

 >>echo $JAVA_HOME
/usr/lib/jvm/java-6-sun

I went through the initial attempt of installing tomcat from apt-get. This resulted in a successfully download of all the files, but I wasn’t able to get tomcat to start up. Not only that, it installed tomcat and created symbolic links everywhere and there were permission issues galore. Thanks to the beauty of slicehost, I just rebuilt my machine from my previous snapshot (luckily I made a snapshot after the previous post).

So, I decided to just download and install tomcat manually. I decided on apache-tomcat-5.5.25.

To get started, download the tarball and extract it somewhere.

wget http://apache.cs.utah.edu/tomcat/tomcat-5/v5.5.25/bin/apache-tomcat-5.5.25.tar.gz
tar xzvf apache-tomcat-5.5.25.tar.gz
cp -R apache-tomcat-5.5.5 <PATH_TO_TOMCAT_INSTALL>

You will need to go to the bin directory and set some file permissions so you can execute some of the files.

cd <PATH_TO_TOMCAT_INSTALL>/bin
sudo chmod a+x *.sh

It’s a probably good time to see if things are looking good. So try,

 >> ./version.sh
Using CATALINA_BASE:   /usr/share/tomcat
Using CATALINA_HOME:   /usr/share/tomcat
Using CATALINA_TMPDIR: /usr/share/tomcat/temp
Using JRE_HOME:       /usr/lib/jvm/java-6-sun
Server version: Apache Tomcat/5.5.25
Server built:   Aug 24 2007 05:33:50
Server number:  5.5.25.0
OS Name:        Linux
OS Version:     2.6.16.29-xen
Architecture:   amd64
JVM Version:    1.6.0-b105
JVM Vendor:     Sun Microsystems Inc.

Sexy. Let’s go ahead and try to startup tomcat.

./startup.sh

By default, tomcat should be running on port 8080. (If you tried to install from apt-get, it’s setup on port 8180)

Setting up the tomcat manager

sudo vi conf/tomcat-users.xml

We need to setup a manager role to see the tomcat status page:

<tomcat-users>
  ...
  <role rolename="manager">
  ...
  <user username="admin" password="mysecretpassword" roles="tomcat,manager">
</tomcat-users>

Restart tomcat and confirm you can log into the Tomcat status page and we’re done!

TODOS:

• I need to setup the system to run tomcat on startup
• I need to write an init.d script
• I need to get tomcat to proxy through apache via mod_jk

When I first got my slice, I had it setup with java and tomcat. Apparently, I updated or rebuilt my slice and forgot to install those two again. Too bad I didn’t take good notes because I totally forgot how to do it.

So this time, I’m going to document it via this post.

I am currently running Ubuntu Feisty (v. 7.04). You can find out what version you’re running by running the following command:

cat /etc/issue

The usual apt-get command allows me to install sun-j2re1.4. That’s not very helpful if I want to compile java code off of my slice or set it up to be a continuous build server. I remember that I had to add a specific repository in order to be able to install the Java SDK via apt-get. After some digging around, I came up with the following:

sudo vi /etc/apt/sources.list

Paste the following into the file:

deb http://archive.ubuntu.com/ubuntu feisty universe multiverse
deb-src http://archive.ubuntu.com/ubuntu feisty universe multiverse

The Ubuntu docs recommend enabling the universe/multiverse security/updates repositories to prevent version mismatches during installs or upgrades but I didn’t run into any issues proceding without them.

Save and exit out of vi.

Next, run

sudo apt-get update

apt-get should be pulling down an updated list of installable packages. So if you type

sudo apt-get install sun-j

and then hit TAB, you should get a list of installable sun packages.

I decided to install Java 6.0 SDK.

sudo apt-get install sun-java6-sdk

It will begin to download and install the SDK. You will have to accept a license. Just hit TAB to get select “OK” and hit enter.

Once it completes, you should be able to confirm the JDK was installed successfully.

  >> javac -version
javac 1.6.0

The next post will lay out steps to install Apache Tomcat.

In the previous post, I quickly created a widgetized blog feed. However, the dynamically generated HTML included links that would open in the same window that the links was on. Under normal circumstances, this is the best user experience. However since Clearspring generates HTML-based feeds in an iframe, clicking on any of the links in the widget caused the page to be rendered in the small, confined space of 300×236 pixels.

I know I could have used document.getElementsByTagName('a') but I was wondering if there was a nicer way to grab all the links on a page. Googling around pointed me to this post. I can get all the links on a page by using document.links, which returns an array of the links on a page as DOM objects. I haven’t tested this on all browsers, but that’s pretty sweet.

Here’s the code in it’s entirety to make all links on a page open up in a new window:

<script type="text/javascript">
var links = document.links;
for( var i = 0 ; i < links.length ; i++ ) {
   links[i].setAttribute('target','_blank');
}
</script>

I came across a Clearspring back a months ago when they were TechCrunch’d and more recently, I came across Wigetized.com, made by a fellow slichoster.

I wanted to try out both and I thought it would be interesting to combine the powers of both services.

I created my widgetized blog feed from wigitized.com, created a widget cname, updated my apache2 config, created a new directory, and pasted in the generated wigetized html into a new file. Oh, and I bounced apache2.

And TA-DA! A widgetized feed!

Next step was to create a new Clearspring Widget from this. Clearspring has done a good job of making this ridiculously easy. You have a couple of options of how to create widget (flash, HTML, js, image). I went with HTML since I had HTML was just to provide the URL to the HTML and a name for the widget.

Once I had the widget added to the Clearspring platform, all I really had to do was publish it and now I have a Clearspring tracked widget.

Next, I’ll be interested in see how I can leverage the platform in different ways to make this widget “viral” and what sort of analytics come with Clearspring to help me track its viralocity (did I make that word up?).

I used to use WP-Syntax but I think this looks oh so nicer!

public class Hello {
  public static void main(String[] args) {
    System.out.println("Hello World!");
  }
}

Check it out at here.