Software-Development on Shaaf's blog

Doing the Locale - Danmark

Wed, 12 Nov 2008 14:52:08 +0100

The following illustrates how to get the Number format working with a danish locale.

text snippet TEXT

	import java.text.NumberFormat;
	import java.util.Currency;
	import java.util.Locale;


	public class TestLocale {

	public static void main(String args[]){
		// Create a Locale for Danmark
		Locale DANMARK = new Locale("da","DK");

 		// get the currency instance for this locale.
 		Currency krone = Currency.getInstance(DANMARK);

 		// Get a Number format for the locale.
 		NumberFormat krFormat = NumberFormat.getCurrencyInstance(DANMARK);
 		// A symbol for the currency
 		String symbol = krFormat.getCurrency().getSymbol();
 		// A double amount
 		double amount = 10000.25;
		// print it out after formatting.
 		System.out.println(krFormat.format(amount));
 		}
	}

How to read a file from the JAR?

Fri, 31 Oct 2008 20:57:54 +0100

Someone just asked me this question today. And I thought might as well put it down for info.

text snippet TEXT

 	public TestReadFileFromJar() throws FileNotFoundException, IOException {
 	InputStream is = getClass().getResource("txtData/states.properties");
 	read(is);
	}

In the case above txtData is placed in the jar on the root. Remmember to add the path with the “/”

Command

Fri, 31 Oct 2008 20:45:04 +0100

By using the command pattern you are seperating the operation from the invoking object. And just because of that it becomes easier to change the command without chagning the caller/s. This means that you could use Command pattern when you might have the following situation

You want to parameterize objects to perform an action You want to specify, execute and queue requests at different times.

Just to quickly start you need a command object, An interface will keep it easy going in this case, thus providing you with the option of extending other classes e.g. Swing MenuItem or Button. Below the execute Method is the one invoked to do something when this command is called or asked to do its stuff. Where as the getCommandName is assumed as a unique name how ever I am sure we can always come up with a better implementation for uniqueness.

Implementing the adapter

Wed, 29 Oct 2008 20:47:56 +0100

Typically when implementing an interface you would have to implement all the methods that exist in that interface. A very good example is the MouseListener in the java Swing. When you need to implement more then one method where as typically you might be catching only one of them. Saying that you would also find a Mouse Adapter provided as well. Some of us use that often. And that is part of the Adapter pattern. It makes life easier for me sometimes.

Abstract Factory pattern

Fri, 10 Oct 2008 10:20:10 +0200

Factories have been a key pattern in building applications, its fascinatingly simple, effective and to the point. When starting to learn a design oriented approach to applications or API, I would always recommend a factory pattern as one of the key starting notes of highlight in your design.

So today I am talking about the Abstract Factory pattern. Its not an “abstract” class or object that you call a pattern. But its a Factory of facotries and that is what exactly makes it so much wordingly abstract. Having “abstract” classes is there but just some other side of the coin.

Quick start Singleton - Walk through

Mon, 23 Jun 2008 03:56:37 +0200

This being my first existence on the network and I just want to make sure that I would come back to this blog page again sometime and keep on writing. For now this is a quick 5 min walk through of getting your hands dirty on the Singleton Pattern. As any ones first pattern Singleton always seems to be the easiest to adapt and ironically always the mistress of your pains; when you realize the act wasn’t right in the first place. More details on that later.