Chinh Do

I feel like I am discovering a whole new world. For my latest project, I have to do a lot of stuff in Java (1.6). While I am familiar with Java the language, I am a total newbie when it comes to Java related technologies, frameworks, and tools. Some of the specific Java technologies and tools I am using are JAXB/JAX-WS web services, Spring Framework, WebSphere Application Server, Maven, Rational Software Architect/Eclipse IDE.

Java Learning Resources

Here are some of the resources I found very useful while learning Java and related technologies in the past several weeks:

Portals

• Java.sun.com – From the creator of Java itself.
• Dzone – It’s like DotNetKicks but has everything including Java stuff.
• IBM Redbooks – Tons of reference materials and everything is free.
• developerWorks: IBM’s version of MSDN. There is a busy community section with forums as well.
• Safari Books Online offers on-demand digital access to reference books. It’s not free, but it’s a great resource if you can read lots of books in a short time. Subscribe to their unlimited account and read all the books you want for a month. Remember to cancel before the month is over. Also remember that IBM Redbooks are free on the Redbooks site. Don’t waste your Safari points on Redbooks. And even if you have an unlimited Safari account, IBM’s site is still better because it offers PDFs.

Java

• Dare Obasanjo’s “A Comparison of Microsoft’s C# Programming Lanauge to Sun Microsystems’ Java Programming Langauge” is the most comprehensive comparison of language features I have found. Highly recommended.
• Essential Java Resources, by Ted Neward, developerWorks. Another highly recommended read. Full of useful links.
• Java Tutorials and Java EE Tutorial from Sun Microsystems.
• Managing the Java classpath (Windows), by Elliotte Rusty Harold (developerWorks).
• Threading lightly series from developerWorks: Part 1, Part 3, Part 3. I found this series while searching for the equivalence of C#’s ThreadStatic attribute: the ThreadLocal class.

Web Services

• Web Services Handbook for WebSphere Application Server Version 6.1. IBM.

Spring Framework

• Data Access Using Spring Framework JDBC, A.P.Raishekhar (devshed.com).
• Getting started with Maven and Spring, by P. Christian.
• Spring Framework Reference (PDF), SpringSource.
• Spring Framework Best Practices, mydeveloperconnection.com.

Eclipse IDE, Rational Software Developer/Architect

• Keeping Eclipse Running Clean, by Riyad Kalla.
• Eclipse Hidden Treasures, by Zviki Cohen.
• Effective Eclipse: Shortcut Keys, by Tomas Karmar.
• Rational Application Developer V7 Programming Guide, IBM.

Misc

• Maven in 5 Minutes, Apache Maven Project.

C# Features I Wish Java Has

I am sure Microsoft was pretty much thinking about Java when they created C#. The Java language itself it very similar to C# in terms of syntax, keywords, and use of punctuations such as semicolons and braces. I have found that most language features in C# have equivalents in Java. However, there are a few notable exceptions which I particularly miss:

• Code regions – I use code regions extensively in C#. Eclipse does support code outlining but it’s only for existing code structures (methods) and is not nearly as flexible as c# regions.
• Properties – Java only has fields and methods. “Properties” are implemented as get* and set* methods. I really miss properties, especially after typing 10 getters and setters in a row.
• var keyword – Another small but very nice feature in C# that helps make code more compact and reduce typing.
• Verbatim (@) strings – Very handy for regular expressions and other string literals that contain lots of escape characters.

Java is still evolving. Here’s hoping that some of the above features will make it into the next version of the language.

I have found that the key to writing good unit tests that interact with the database is making sure that the data is in a known state before and after the test. System.Transactions makes this very easy. All you have to do is wrap your unit test inside a TransactionScope and rollback at the end.

For example, in the test below, I am testing the update feature of my Customer data access class. To make sure I have a customer to update, I create it myself at the start of test, then I update it. At the end, scope.dispose() rolls back the whole thing. The database should look exactly like it was before my test.

[TestMethod]

public void CanUpdateCustomer()

{

    using (TransactionScope scope = new TransactionScope) {

        Customer customer = CreateTestCustomer();

        customerDac.saveCustomer(customer);

        customer.Phone1 = "804-555-1212";

        customerDac.updateCustomer(customer);

        // TODO: verify that update works

        scope.Dispose(); // roll back

    }

}

Here are a few more tips I have for unit tests that interact with the database:

• Maintain scripts to create/rebuild a starting-point database. The starting-point database may contain some data such as lookup data, codes, etc. If your unit tests work correctly, the database will stay the same across tests. With the rebuild scripts, you can easily rebuild in the case of other mishaps or a bug in one of the unit tests causing corrupt data.
• If you need to create a database record that doesn’t have an auto-generated key, use a random key to minimize the chance that your test will collide with another test running somewhere else. Seed your random generator with Environment.TickCount or a hash code of the machine name or user name.
• With my Transactional File Manager, you can also restore the state of the file system in addition to the database. Transactional File Manager is great at automatically cleaning up any temporary files you create in your unit tests.
• Don’t assume your code is the only thing that is touching the database. If the count of records in a table is x, it won’t necessarily be x + 1 after you add a new record to the table. Somebody else may have added to or deleted from the table while your test is running.

For Java programmers, try using Spring TestContext Framework. It’s a bit more complicated to use but it works just as well.

This is an update to my original article that was based on Silverlight 1.0 alpha. The code for the old article no longer worked with the current Silverlight runtime.

Instead of the traditional and simple display of a string, this Hello World application uses animation in code to say “hello”.

Pre-requisites

You will need to have the following installed:

• Visual Studio 2008 with Service Pack 1
• Silverlight 2.0 Runtime
• Silverlight Tools for Visual Studio 2008 SP1

Create a New Silverlight Project

• In Visual Studio 2008, choose File/New/Project and select Visual C#/Silverlight/Silverlight Application. The Silverlight project type is added when you install the Silverlight Tools.
• Give your project a name and choose OK.

  

• On the next dialog window, accept the default “Add a new ASP.NET Web project…” and choose OK.

Silverlight Project Files

Since we will be drawing objects, we need a Canvas control instead of the default Grid. Change your Page.xaml file to read like this:

<UserControl x:Class="SilverlightHelloWorld.Page"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    Width="520" Height="140" Loaded="UserControl_Loaded">

    <Canvas x:Name="MyCanvas"/>

</UserControl>

Press F7 when you have Page.xaml opened to switch to the code-behind file Page.xaml.cs, and replace the code there with this code:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using System.Windows.Threading;

namespace SilverlightHelloWorld

{

    public partial class Page : UserControl

    {

        // private Storyboard _timer = new Storyboard();

        private DispatcherTimer _timer;

        private List<Cell> cells = new List<Cell>(); // list of all cells

        private int _xSize = 26; // width of the grid, in number of cells

        private int _ySize = 7; // height of the grid

        private int _numCells; // total number of cells

        private int _cellIdx = 0;

        /// <summary>Represents a cell on the grid</summary>

        private class Cell

        {

            public double X; // x-coordinate of cell

            public double Y; // y-coordinate

            public bool On; // True if cell is "on"

            public double Order; // Display order

        }

        public Page()

        {

            InitializeComponent();

        }

        private void UserControl_Loaded(object sender, RoutedEventArgs e)

        {

            // Assign a random value to each cell 

            Random rnd = new Random(Environment.TickCount);

            _numCells = (int)(_xSize * _ySize);

            string template = "                          "

                + " x  x xxxx x    x     xx  "

                + " x  x x    x    x    x  x "

                + " xxxx xxxx x    x    x  x "

                + " x  x x    x    x    x  x "

                + " x  x xxxx xxxx xxxx  xx  "

                + "                          ";

            for (int y = 0; y < _ySize; y++)

            {

                for (int x = 0; x < _xSize; x++)

                {

                    Cell cell = new Cell();

                    cell.X = x * (this.Width / _xSize);

                    cell.Y = y * (this.Height / _ySize);

                    cell.Order = rnd.NextDouble();

                    cells.Add(cell);

                }

            }

            for (int i = 0; i < template.Length; i++)

            {

                cells[i].On = template[i] == 'x';

            }

            // Sort the cells by the random values

            cells.Sort(

                delegate(Cell c0, Cell c1)

                {

                    return c0.Order.CompareTo(c1.Order);

                }

            );

            _timer = new System.Windows.Threading.DispatcherTimer();

            _timer.Interval = TimeSpan.FromMilliseconds(1);

            _timer.Tick += new EventHandler(timer_Completed);

            _timer.Start();

        }

        void timer_Completed(object sender, EventArgs e)

        {

            if (_cellIdx < _numCells)

            {

                // Get the next cell

                Cell cell = cells[_cellIdx];

                // Draw the cell

                Rectangle r = new Rectangle();

                r.Stroke = new SolidColorBrush(Colors.DarkGray);

                if (cell.On)

                {

                    r.Fill = new SolidColorBrush(Colors.Red);

                }

                else

                {

                    r.Fill = new SolidColorBrush(Colors.LightGray);

                }

                r.Width = this.Width / _xSize;

                r.Height = this.Height / _ySize;

                r.SetValue(Canvas.LeftProperty, cell.X);

                r.SetValue(Canvas.TopProperty, cell.Y);

                MyCanvas.Children.Add(r);

                _cellIdx++;

            }

            else

            {

                _timer.Stop();

            }

        }

    }

}

Save the file. Right click on SilverlightHellowordTestPage.aspx and choose Set As Start Page, then run the app.

Hosting the Application

To host the application on your web site, just copy the following files:

• Silverlight.js
• SilverlightHelloWorldTestPage.html
• ClientBin/SilverlightHelloWorld.xap

Click here to see the application in action.

A while ago I had been posting my Finds of the Weeks series and this is the continuation of that. Instead of weekly though, this series will be more of a “whenever possible” kind of thing.

General Programming

• Some code optimizations can actually slow down your app. Beautiful Code: False Optimizations by sernaferna.
• Quad core + 8GB RAM + Server 2008 with Hyper-V = A Great Dev Environment. By Craig Lussier.
• I started using JQuery a few months ago and it’s now my favorite Javascript library. Combine with Visual Studio 2008’s Javascript intellisense, and you have scripting nirvana.
• jqModal is a modal dialog plug-in for JQuery. Worked great for a project I was working on two months ago.
• Safari Books Online is a great online programming books service. For a monthly fee, you get to read several books using your browser. The browser interface is not great, but the price is much lower than actually buying the book.
• Randomly ordering an array is simple. That’s what I thought until I ran across Techniques for Randomly Reordering an Array (by Scott Michell).

.NET/C# Stuff

• Eugene Osovetsky explained a few peculiarities when consuming WCF services from Visual Studio 2003: Solving the “disappearing data” issue when using Add Web Reference or Wsdl.exe with WCF services.
• If you have a DataReader and don’t intend to read all records from it, call IDbCommand.Cancel before you call IDataReader.Close so that the rest of the unread records are skipped.
• Scott Hanselman: Assembly Fiefdoms: What’s the Right Number of Assemblies/Libraries?
• VS.NET Tip of the Day: Reusing C# Source Code Across Multiple Assemblies. By ShawnVN.
• Setting the log file location at runtime with a DOM configured log4net. By Keyley on Kode.
• WCF – Recommended Settings for Tracing and Message Logging. MSDN.
• WCF – Enabling Performance Counters. By Nicholas Allen.
• One of these days I’ll get back into Windows Mobile programming. Adjust Your Ring Volume For Ambient Noise, Chris Mitchell.
• Did you know ReSharper supports wildcards in its Go To Type dialog box? Joe White’s 31 Days of ReSharper series is a must read for ReSharper fanatics like me.
• Is image processing in C++ a thing of the past? Discover Enhanced Image Manipulation with GDI+ (by Tade Oyebode).
• DataContractSerializer can be used to deserialize WCF messages.
• Unraveling the Mysteries of .NET 2.0 Configuration, by Jon Rista.

Database

• Stefan Delmarco talked about the NEWSEQUENTIALID function in SQL Server 2005.
• Mutexes are fun: Application Locks (or Mutexes) in SQL Server 2005. Mladen Prajdic.

Windows

• Experiencing strange issues with your Windows (like dialog boxes that don’t show up)? You may be having a desktop heap issue. Try these articles:
  • Windows XP flakiness – solved. By Kevin Dente.
  • “Out of Memory” error message appears when you have a large number of programs running. Microsoft Support.
• If IE crashes when you try to open SharePoint documents, try this fix: regsvr32 “C:\Program Files\Microsoft Office\OFFICE11\OWSSUPP.DLL”.

Software, Tools, etc.

• If you have a Linksys WRT54* router, I highly recommend loading Tomato firmware. I have been using it for about 6 months now and it’s so much better than the built-in Linksys firmware. Tomato’s QOS works great to make sure my Vonage phone line remains usable at all times.

PowerShell

• Ben Pierce posted a series of very useful PowerShell command-line demos: Demo1 (Administering Windows), Demo 2 (Administering Servers in bulk), Demo 3 (How do I Know Which Class to Use), Demo 4 (Administering Hyper-V).

Something Different

• World War is a very nicely done digital animation by Vincent Chai. My son can watch it for hours.
• Your browsing history can be used by any web site out there to guess your gender. Using your browser URL history to estimate gender, by Mike on Ads.
• Humans can fly (video).
• A fascinating into the human mind: The Interpreter (Has a remote Amazonian tribe upended our understanding of language?). By John Colapinto.

I googled and didn’t find anything useful so I thought I’d share this. If you have a VISA gift card and want to use it on Amazon.com in conjunction with a credit card (to pay for any amount over the gift card value), the trick is to use the VISA gift card to purchase an Amazon gift card of the same value for yourself (search for “gift card” on Amazon.com).

Once you have the Amazon gift card, you can then use it to pay for part of your order, with the remaining balance being charged to another credit card.

I am sure this trick works with most other online merchants too.

On my home network, I have a media file server running Vista 64-bit that serves out music and movies. Since everything is behind a router, I decided to make the shared media folders accessible to anyone on my home network. All you have to do is browse to the media server and start accessing content, without having to log in.

To enable anonymous browsing of a shared folder that is shared by a Vista PC (that is not on a domain), do the following:

• Enable the Guest Account:
• Run "lusrmgr.msc", select the Users folder.
• Right click on the Guest user and choose Properttes.
• Uncheck "Account is disabled".

  

• Enable "Public folder sharing" and disable "Password protected sharing":
• Choose Start, right click on Network, and choose Properties.
• Enable "Public folder sharing".
• Disable "Password protected sharing".

  

• For each shared folder:
• Grant Everyone Read permission to the Share.
• Grant Everyone Read and Execute (NTFS) permission on the shared folder itself.

  

At home, I occasionally need to print color posters and black and white flyers. I’ve found FedEx Office Online Printing Service to be very convenient for this (if you know exactly what you want… more on that later). After you upload your file in one of the supported formats (Word, PowerPoint, Excel, RTF, Post Script, PDF, Text, JPG), select a paper size, and set print options (color/black and white, copies, collation, paper stock, etc.), the web site gives you a preview of the final print output.

For my last print job, the file I wanted to print was in CorelDRAW format, so all I had to do is go into CorelDRAW and export it to Post Script format. The final print output looked perfect to me.

There is a "minor" problem with the service however: there are no prices to be found on the site anywhere. No, the printing is not free, sorry. You do eventually see the total price when you check out. The only reason I can think of for this strange "price hiding" practice is so that people can’t easily compare online prices vs walk-in prices. They obviously have complete pricing data in the system, because the site does give you a total at checkout. This lack of up-front pricing is a major hassle, especially if you are not sure which options you want (type of paper, etc). You can’t easily/quickly compare the different printing options (and there are tons of them). Changing your order and going through the checkout process just to see the price is too cumbersome.

One has to ask, what were they thinking??? I certainly hope this is not a trend among online stores. And don’t you hate it when you google something (such as "FeDex Kinko’s prices") and the first thing you find is other people also looking for the same info and not finding any .

Here are some actual prices I got recently (December 2008) for my local FedEx Kinko’s (Richmond, VA):

- 8×11, B&W, 30% Recycled Paper: 10c/page.
- 8×11, B&W, Standard Laser Paper: 12c/page.
- 8×11, Color, Standard Laser Paper: 59c/page.
- 17×11, Color, Standard Paper, 1.78/page

There is a volume discount when you order more than x copies. It seems that the discount starts at 100 copies.

I found a memory leak in my Transactional File Manager, so here’s version 1.0.1 with a fix for the leak. Click here to download.

Update (6/8/2010) – This project is now in CodePlex. URL: http://transactionalfilemgr.codeplex.com/

Against popular wisdom, I decided to upgrade my bedroom home theater PC to Vista 64-bit a couple days ago (just have to make full use of all of my precious 4GB of RAM). Everything is working surprising well so far, with the exception of sound! Whenever I play any audio, my speakers now produce all kinds of pops and crackles along with the normal audio stream. Urgg.

After a couple of days of googling, tweeking various sound settings, uninstalling/reinstalling drivers, etc. without success, I almost gave up on the thing. Then I decided to try just one more thing, changing the default sample rate to “2 channel, 16 bit, 44100 Hz (CD Quality)” from the default “2 channel, 24 bit, 48000Hz” and just like magic, the pops and crackles are gone.

Nice surprise logging into Gmail just now: Themes! I tried out a few and have to say they are nice to look at. I almost forgot I have actual emails to read. I’m going to try out a cheery theme to offset the grim news from Wall Street.

There’s even a Terminal theme for die UNIX shell diehards. It’s actually kind of cool… if only for a few minutes.

More info from the official Gmail blog.