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Creating a remote GIT repository

Clean, readable code is one of my highest goals when writing code.  I’m always thinking about the next guy, even when the next guy is just me, several months from now.   Nothing is worse than going into spagetti code and not knowing what the heck is going on.  Because of this, I like to refactor my code A LOT.  When you are using source control, you never get yourself into situations that you can’t get out of.  It’s also nice to go back and see how the code has evolved over time, to see why certain files were changed.  Because of all these benefits, I use source control even on my own tiny projects where I’m the only developer.

I have used visual source safe when I first got started and like all vss users, quickly moved away from it.  I’ve spent most of my career using perforce for work.  I tried out Subversion a long time ago, but I got tired of my database getting corrupted and having to drop to the command line to repair it.  I used a very early version of subversion and I hear that it is MUCH better now.  Anyway, I used perforce for my personal stuff because the first two clients were free.  Since I’m learning everything else, why not throw in GIT too.  It’s gotten a lot of press so I want to see what the fuss is all about.  Here is how I installed my first GIT repository on my ubuntu server.

ssh to the remote box and type the following commands:

sudo apt-get install git-core
sudo mkdir /var/git
sudo mkdir /var/git/snowcaptech.git
sudo chown jason /var/git/snowcaptech.git
sudo chmod 775 /var/git/snowcaptech.git
cd /var/git/snowcaptech.git
git init --bare --shared=group

What we are doing is creating an empty directory in the /var/git folder where I like to keep all my git repositories.  We are then changing the owner to me and setting permissions for me to write and everyone else to be able to read.  The git init –bare creates a repository without a working copy.

then to add a project from your local client to the remote repository, you would first tell GIT about your project by going to the directory of your project and from a command prompt typing:

git init
git add .
git commit -m "initial checkin"

This initializes your repository and commits it to your local GIT repository.  This is all you need to do to have a working source control system for just yourself.

I like to make my source available on a server so I can access it from anywhere on the planet.  I never need to do this, but it is cool to be able to do this.  In order to “push” your local GIT repository to the remote repository, you have to tell your local repository about the remote.  Sorry if that was confusing.  Read it a few times. :) 

git remote add origin jason@dev.snowtech.com:/var/git/snowcaptech.git
git push origin master

As long as your settings are all correct, your repository should now be at the remote repository.

2009 12 20 jason Ubuntu Comments (0) Permalink

Windows Mobile Smartphone vs Pocket PC

I recently encountered an issue where a Windows Mobile 5 application I wrote wasn’t working on a Windows Mobile 6 smart phone.  This particular phone was in Spain so I was not able to hold it in my hands.

Initially I believed it was because I didn’t have the Windows Mobile 6 SDK installed.  I needed the app to be backward compatible to Windows Mobile 5 so I haven’t messed around with the new SDK yet.  When I looked (skimmed) through the documentation, everything led me to believe that most windows mobile 5 apps will run on a Windows Mobile 6 device.  There is the exception that if you are using undocumented APIs, they aren’t guaranteed to work.  Since the app I’m working on logs GPS coordinates in the background, it was possible that I was using some calls through a 3rd party library.

Turns out my problem was much more basic.  Once I got my hands on an actual Windows Mobile 5 smart device to test on, I discovered the problem right away.  The app was failing when it tried to create a list box.  My simplistic thinking was that you write applications for “Windows Mobile 5″.  You actually write for either Windows Mobile Smartphones or Windows Mobile Pocket PCs.  One is more limited than the other.  The naming is still confusing to me.  My iPhone is a “smart phone” so I assumed that Smartphone was simply Pocket PC + phone.  WRONG.  Windows Mobile 6 makes it even worse.  They label one sdk “standard” and the other “professional”.  I am pretty sure professional = pocket pc = more functionality.

So I learned that if you want to write lowest common denominator applications for Windows Mobile, you need to target the smart phone.  And you should really test your interface at different resolutions because those smart phones have tiny screens.

2009 12 20 jason Mobile Devices
Windows Mobile Comments (0) Permalink

Java ME Date add functionality

Programming for the blackberry can be frustrating.  It seems that they have taken every useful function I’ve used in the past and thought “is there a harder way to do this already?”  If the answer was yes, they ripped out the function.  The latest example I’ve uncovered while developing is simply adding time and dates to arrive at some time in the future.  I am trying to add a number of seconds to an existing timestamp.  In standard Java, there is a handy add function that does this for you.  Unfortunately, in Java ME, they have ripped it out.  To get that functionality back, you need to understand when you call getTime() on a date, it returns the number of milliseconds since January 1, 1970, 00:00:00 GMT as a long. The value “1″ represents one millisecond.  So, to add one day to your date, you simply need to determine how many milliseconds in one day and add that to the value returned by getTime().

int milliseconds = 1 * 1000 * 60 * 60 * 24;  // 1 day * 1000 milliseconds/second * 60 seconds/minute * 60 minutes/hour * 24 hours/day
Date newDate = new Date(myDate.getTime() + milliseconds);

This will add one day to your date.

2009 11 09 jason BlackBerry Comments (0) Permalink

Making an HTTP Request on BlackBerry

Seems like it is rather complex to make a simple HTTP request on BlackBerry.  The code for opening a connection is straightforward:

String url = "http://10.0.0.1";
HttpConnection conn = conn = (HttpConnection)Connector.open(url);

The complexity comes in because I am developing on a  BlackBerry device without service.  When I try to execute the above code, I get an IOException stating “Tunnel failed”.  From searching, it appears that I get this message because APN is not set.  I can not set it because I do not have service for this phone.  If you don’t have the APN set, it does not automatically try and use the WIFI connection.  Apparently there are six different methods for using a connection.  Each one of these requires a different string appended to the URL to determine which one gets used.

BlackBerry MDS

The first method is using BlackBerry MDS.  This forces all traffic to go through the BlackBerry enterprise server.  It encrypts all traffic using AES or Triple DES.  My task is to specifically avoid using the MDS because we are creating a cloud service where the customer does not need to have any server let alone a BlackBerry enterprise server.

String url = "http://10.0.0.1;deviceside=false";

BlackBerry Internet Service

The second method is to use the BlackBerry Internet Service.  This is only available to approved BlackBerry Alliance Program members.  There are different tiers. The public tier which is free does not offer the BlackBerry Internet service feature.  The minimum tier that supports this is the BlackBerry Alliance Associate Member which costs $2,000/yr and requires 45 member points.  To get this, you basically have to make losts of money using the BlackBerry platform or promot it in other ways.  You can look at their FAQ for more details, but basically we don’t have this option available to me right now.

TCP Stack

The third method is to use the TCP stack directly.  In order to use this, you need to have the APN username and password.

String url = "http://10.0.0.1;deviceside=true";

Wi-Fi

The fourth method is to use wi-fi.  This is what I’m interested in right now.

String url = "http://10.0.0.1;interface=wifi";

WAP 1.x

The fifth method is to use WAP 1.x gateway.  This is supported over the carriers networks.  You have to contact the carriers to get a list of their WAP gateway parameters.

String url = "http://10.0.0.1;WAPGatewayIP=127.0.0.1;WAPGatewayAPN=carrier.com.gprs";

WAP 2.0

The sixth way is to use WAP 2.0.  You need to loop through the records and find the uid of the desired ServiceRecord in the ServiceBook.  This is simpler than WAP 1.x because you don’t need all the gateways and settings from the carriers.  This is supported as of 4.2 on the BlackBerry.

// String uid = get from the device
String url = "http://10.0.0.1;ConnectionUID=" + uid;

Going Forward

I would really like the device to try wi-fi first before attempting to use the potentially expensive data plan.  I am going to have to write some code to test the wi-fi first, and then attempt the data connection if this fails.  It is conceivable that the user wouldn’t want the app to transmit unless the wi-fi connection is available.  Not as simple as just opening up a connection and firing off a GET request.

2009 10 06 jason BlackBerry Comments (3) Permalink

Blackberry development environment

Blackberry applications are written in Java.  Since the java mantra is write once, test everywhere.  er.  sorry, run everywhere.  You would think that you could choose whatever OS you would like to develop for the Blackberry.  While the documentation claims you can write Blackberry code on any platform, the reality for a new developer is quite different.  The Eclipse plugin they offer only runs on Windows.  Very irritating considering I can run eclipse on my Mac as well as my Windows machine.  Rather than fight it, I am going with the flow and using Windows XP 32bit inside my Parallels virtual machine.

Very important that you pay attention to the version of eclipse that the plugin works with.  I didn’t and installed the lastest eclipse (3.5 as I write this).  I went to “Help > install new software…” using “http://www.blackberry.com/go/eclipseUpdate”.  I got the following error:

Cannot complete the install because one or more required items could not be found.
  Software being installed: BlackBerry JDE Plug-in for Eclipse 1.0.0.67 (net.rim.EclipseJDE.feature.group 1.0.0.67)
  Missing requirement: BlackBerry JDE Plug-in for Eclipse 1.0.0.67 (net.rim.EclipseJDE.feature.group 1.0.0.67)
  requires 'org.eclipse.debug.ui [3.4.0,3.5.0)' but it could not be found

I had to download the gannymede 3.4.2 version of eclipse and install it.  Then I did the software update using the http://www.blackberry.com/go/eclipseUpdate URL.  It prompted me half a dozen times for my Blackberry Developer zone ID.  I dutifully entered it each time (annoying).  After this, I had a working environment.

In the BlackBerry JDE Plug-in for Eclipse Installation and Configuration demo video, They show configuring the BlackBerry workspace.  Well, this option is not enabled until you created a BlackBerry project.  Also in this video, you will see them run the simulator just by clicking run.  This did not work for me.  In order to actually launch the application in the simulator, you need to right click the project and select “Activate for Blackberry”.  If you don’t do this, Eclipse will launch the simulator and you will see debug output, but your project will not show up on the device.

The next step is to get it working on an actual BlackBerry device.  When I first attempted this, it would not work with my old version of parallels.  I updated to the latest build of parallels and then Windows could recognize the USB device.  My mac took control and parallels did not prompt me like it usually does when I connect a USB device.  There is an icon in the lower right of the frame.  Click the USB icon there and select “Research in Motion”

I haven’t been able to get the Eclipse IDE to install and run the application on my device.  I’ve had to use the tool JavaLoader.exe which is located in the bin directory of your JDE installation.

JavaLoader.exe -usb load HelloWorld.jad
JavaLoader.exe -usb erase -f HelloWorld.jad

These commands will install and remove your application.  This assumes that the bin directory is in your path and you are in the location where your *.jad and *.cod file.

2009 10 05 jason BlackBerry Comments (0) Permalink

Install MySql5 on Snow Leopard using MacPorts

Install MacPorts before you do anything.

Install MySQL5

sudo port install mysql5
sudo port install mysql5-server 
sudo -u mysql mysql_install_db5

Secure MySQL5

To secure your MySQL5 installation, you can either change the password manually like so:

/opt/local/lib/mysql5/bin/mysqladmin -u root password {new-password}

or on a production system, you can run the secure script and not only change the password, but remove anonymous access and prevent remote root login.

/opt/local/lib/mysql5/bin/mysql_secure_installation

To start the MySQL daemon, type:

sudo /opt/local/lib/mysql5/bin/mysqld_safe &

or to make sure MySQL5 is launched at startup every time:

sudo launchctl load -w /Library/LaunchDaemons/org.macports.mysql5.plist
sudo launchctl load -w /Library/LaunchDaemons/org.macports.mysql5.plist

Create a symbolic link

sudo ln -s /opt/local/bin/mysql5 /opt/local/bin/mysql

Test the installation

mysql -u root -p

It should prompt you for a password and you should see the “mysql>” prompt

2009 10 01 admin MySQL Comments (3) Permalink

Install Ruby on Rails for Mac Snow Leopard using MacPorts

Not sure why but I had a heck of a time running my ruby on rails code after updating my Mac to Snow Leopard. I use MacPorts to do my development so I simply removed it and all of my ports as well as the gem I had installed in my home folder.  I went through a complete uninstall/reinstall several times before I found the combinations that worked for me.  These are the last steps I did where it worked…

sudo rm -rf /opt
sudo rm -rf .gem

I downloaded and installed the latest MacPorts (1.8).

I then executed the following commands:

sudo port selfupdate
 sudo port sync
 sudo port install ruby
 sudo port install git-core +svn
 sudo port install rb-rubygems
 sudo gem update --system
 sudo env ARCHFLAGS="-arch x86_64" gem install sqlite3-ruby -- --with-sqlite3-dir=/opt/local
 sudo gem install rails cucumber

I got a lot of “No definition for” warnings on the RDoc for sqlite3-ruby-1.2.5 but it doesn’t seem to matter.

Thanks to Ken Collins for his great blog entry that goes into much more detail.

2009 09 26 admin Ruby Comments (0) Permalink

Six degrees of Barack Obama

You’ve heard of the six degrees of Kevin Bacon?  It is the concept that you can connect to anyone in the world in six steps or less.  Microsoft has demonstrated this after checking (snooping?) through 30 billion IM conversations.  Well, anyone who knows me can (if they couldn’t before) trace their route to President Barack Obama.  Today my sister introduced me to her boss of many years, Ted Mondale.  Ted is a former MN state senator, and the son of the former Vice President of the United States Walter Mondale.  Walter’s boss was JimmyCarter, the President of the United States (POTUS for you West Wing fans).  Jimmy is in the very exclusive club of men who answer to the title “Mr. President” of which Barack Obama is the newest member.  So there you have it.

Step 1: you -> me  :^)
Step 2: me -> Shawna Rosso (my lovely sister)
Step 3: Shawna -> Ted Mondale (son of former Vice President)
Step 4: Ted -> Walter Mondale (former Vice President)
Step 5: Walter -> Jimmy Carter (former President)
Step 6: Jimmy -> Barack Obama (current President)

2009 09 23 jason Uncategorized Comments (0) Permalink

Blackberry preferred development platform is Windows

Well, I am in the middle of learning to write my first blackberry application. Since Blackberry uses the Java platform so heavily, I was excited to be able to develop natively on the Mac. Apparently there is no easy way to actually do this. I am used to using Eclipse for my java development so I was excited that Blackberry had an Eclipse plugin. I was very disappointed to learn that this plugin only works on a Windows machine. I believe it is the Simulators that cause the problem. I didn’t want to spend days fighting this issue, so I gave up and installed Eclipse on a Windows 32bit virtual machine. I was quite bummed to have to do this. I don’t understand why they go to so much trouble implementing the JME which is platform neutral, and then totally bomb when it comes to forcing developers to develop on a Windows box. I think it is crucial for them to support more than Windows so they can attract the thousands of iPhone developers that love their Macs (like me). Or maybe they know that if you really want to develop for the blackberry, you will just install Windows. I am looking forward to some Android development…

2009 09 22 admin BlackBerry Comments (0) Permalink

Do certain languages attract bad developers?

Why is it that every time I come in to fix a VB project, the code is awful?  This current one is probably the worst.  It is sloppy.  It is riddled with security vulnerabilities.  it is filled with files named “checkout.aspx”, “checkout2.aspx”, etc.  No source control.  No dev or staging enviornment.  They were using the production database for development. They don’t understand the concept of reuse or refactoring.  I fixed the exact same bug 20 times because they have cut and paste this code everywhere.   I’m not getting paid to clean up the code, just fix the vulnerabilities.

So my question is why does VB attract so many BAD developers. Javascript tends to do the same thing.

Why?  You can write really good javascript code.  You can write really good vb code (although it will always be ugly).  I just don’t understand why every vb project I look at appears that 10 year olds wrote it.

Now that I think about this some more, I’ve seen some really really horrible C++ code too.  I’m going to have to think about this one.  I’m just so tired of cleaning up after VB coders.

2009 08 27 admin Uncategorized Comments (0) Permalink