5 tips you can use while debugging your Java code in Eclipse.

1. Logical Structure
   The logical structure is very handy for examining things like maps and other java collections classes, instead of showing the full detail of all the internal variables the view will only show the “logical” pieces. It is activated/deactivated from “Variables” view using logical structure toggle button.

   

   

   
   

2. Conditional Debugging
   Once you know where an error occurs, you will want to see what the program is doing right before it crashes. One way to do this is to step through every statement in the program, one at a time, until you reach the point of concern. Sometimes it’s better to just run a section of code and stop execution at that point so you can examine data at that location. It’s possible to declare conditional breakpoints triggered whenever the value of an expression changes. In addition, code assist is available when typing in the conditional expression.

   Right click your breakpoint and select Breakpoint Properties… to set a condition. Check “Enable Condition” box and write your expression below it. You can define a “hit count” that stops your code after that count is reached if you want.

   

3. Java Exception Breakpoint
   Use “Java Exception Breakpoint” feature to track your exceptions more easily. For example, your program might be throwing a NullPointerException or FileNotFoundException and you want to track it down. Rather than go to the line of code and set a breakpoint, you can specify that the debugger should always stop when the exception occurs.

   

4. Step Filtering
   “Step Into” is one of the most used feature while debugging the source code. Sometimes, it takes us through several stack traces to reach the code we want to debug. In such cases, “Step with Filters” functionality can help us. It simply filters out the classes that we don’t want to step into.

   To specify which classes to filter out when “Step with Filters” is used, the preferences must be set. To activate the preferences panel choose Window > Preferences from the main window. Once there navigate to Java > Debug > Step Filtering and choose the classes/packages to be filtered out. When you step through the code, ensure that the “Use Step Filters” toggle button in Debug view is on.

   

   

5. Expression Evaluation
   “Inspect” is a handy feature for evaluating your expressions. In the Debug perspective, select your expression, right click it and select “Inspect” from the menu to evaluate. You can do it by simply Ctrl+Shift+I key combination.

   

   “Display View” is another efficient helper in evaluating expressions. Activate it from Window > Show View > Display, write your expressions to evaluate and execute them by right clicking and selecting “Display” from the context menu in the Debug perspective or simply by Ctrl+Shift+D shortcut. You can use code assist (Ctrl+Space) to compose your expressions.

   

Happy debugging.

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1. Last.fm
   Users can create custom radio stations and playlist from any of the audio tracks in Last.fm’s music library, and are able to listen to some individual tracks on demand, or download tracks if the rights holder has previously authorised it.

   

2. Imeem
   Imeem is a social media service where users interact with each other by watching, posting, and sharing content of all digital media types, including blogs, photos, audio, and video.

   

3. Pandora
   Pandora is an automated music recommendation and Internet radio service (US only for now).

   

4. Finetune
   Type an artist’s name, finetune creates a playlist of related songs for you to listen to. Explore the finetune community - browse artists, users, playlists and more.

   

5. Mog
   Listen to millions of full-length songs for free. Share your music library, playlists and opinions on music. Discover music recommended by users who share your musical tastes.

   

6. Myspace Music
   MySpace is now one of the biggest social network site on the Internet. So it’s obviously a great place to hunt for music if you are looking for recommendations from friends.

   

7. iLike
   Discover new music with your friends. Over 20 million people use iLike to share music tastes and playlists, and to learn about new artists and concerts together.

   

8. RadioBlogClub
   Bookmark your favorite tracks and build-up your playlist. Then listen to your juke.blog player.

   

9. Jango
   Custom radio that plays the music you want.

   

10. iJigg
    Discover, rate and download free music.

    

11. Grooveshark
    Free streaming. Social networking. Music discovery.

    

12. Live365
    Thousands of free online radio stations.

    

13. Musicovery
    Interactive web radio with attractive user interface.

    

14. UPlayMe
    Keep up with friends and meet people through the music & videos you’re playing right now.

    

15. QLoud
    Qloud provides the music experience users want: unlimited, on-demand, free music from endless library.

    

16. Audiofarm
    Audio sharing.

    

17. Mystrands Music
    Browse and share popular music.

    

18. Musicmesh
    Discover related music and artists.

    

19. Jiwa
    Hundreds of thousands of songs to listen to unlimited.

    

20. Soundpedia
    Rediscover music you like.

    

21. Media Master
    Your music. Anywhere.

    

22. Deezer
    Music on-demand.

    

23. Sideload
    Free music on the internet to sideload into your locker.

    

24. Tun3r
    Your mood. Your station.

    

25. Fiql
    Source for music and video playlists.

    

Happy listening.

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Sometimes, I cannot find time to read my daily selected articles. I bookmark them, later I forget to read. E-mailing those articles can be a solution, however it is not effective and takes time to manage.

“Read It Later” is a Firefox extension that creates a manageable list of links to be read later. New features of it for Firefox 3 users are:

• One click saving, sorting, tagging
• Sync your list with any number of computers
• Offline reading
• Access anywhere
• RSS feeds
• Click to save mode
• Save all tabs for later

Let’s see it in action:

1. You like a page and want to save it for later reading. Just click the little “tick” at the end of the address bar. It is added your list and the little “tick” turns red. You can add links to your list by right clicking on the link and selecting “Read This Link Later”.

   

2. You want to read them now. Click the little “book” icon in the navigation toolbar and select the desired link from the list.

   

3. You are complete with the link and want to delete it from the list. Just click the “tick” icon in the address bar one more time, select the “Just Mark As Read” button to delete it. You can add your link to losts of social sites here before deletion if you want.

   

Tip: You can add links to your list quickly with the “Click to Save Mode” option. You click the links and they are added to your list automatically rather than followed through. It is activated by pressing “Alt + m” or clicking the little red “tick” icon in the bottom right corner. Try it.

Detailed explaination about “Read It Later” is here.
Firefox add-on page for “Read It Later” is here.

I think, it is great. Happy reading.

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• 8,002,530

I personally use Google Reader for reading RSS/Atom feeds. It is online, clean, simple and effective. I highly recommend it if you haven’t used it before.

In this article, I’ll share Google Reader shortcuts I frequently use. Trust me, your feed reading speed will increase reasonably. Let’s get started:

1. m
   Mark as read/unread the selected item.
2. n/p
   Scan down/up. Selects the next/previous item without opening it in the List View. Use shift-n/p for selecting the next/previous subscription or folder in the navigation panel.
3. j/k
   Selects the next/previous item in the list.
4. o
   Open/Close item in the List View. enter can be used as well for the same purpose. Use shift-o to open the item currently selected in the navigation panel.
5. u
   Toggle full screen mode.
6. r
   Refresh the unread counts.
7. shift-a
   Mark all items as read.
8. v
   Open the original article in a new window.
9. shift-s
   Toggle share.
10. 1
    Show items in Expanded View.
11. 2
    Show items in List View.
12. a
    Add a new subscription.

You can find the complete listing here.
Happy reading.

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Here is my top source code seach engines and I wanna share them with you.

1. Google Code Search

   

2. Krugle
   



3. Byte My Code
   



4. Dzone Snippets
   



5. Code Fetch
   



6. Codase
   



7. Snipplr
   



8. O’reilly Code Search
   



9. JSourcery
   



10. Merobase
    

Please share yours with us.
Happy coding.

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Can you print out “Hello World!” without writing a main method in Java? Think for a while. Yes, you’re right. It can be possible using “static initialization blocks”. Let’s see the source code first:

So, what is “static initializer block”?

• A static initializer block is defined using the keyword static.
• The code in a static initializer block is executed once by the virtual machine when the class is loaded.
• A static initializer block cannot contain a return statement. Therefore, no need to specify a return type.
• A static initializer block doesn’t have an argument list.
• It can initialize only static data members of the class.

Because the static initializer block is executed when the class is first loaded, we can print out “Hello World” without writing a main method. The execution is stopped using “System.exit()” command. So, we prevent “main method not found” error. It is tricky. Isn’t it?

Happy coding.

Note: Write fully qualified class name (for our example “net.cavdar.staticinitializer.HelloWorldWithoutMain”) for configuring run options for main class, if you need.

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I played with JUnit 4 library this weekend and here is the short introduction to it:

1. @Test
   Mark your test cases with @Test annotations. You don’t need to prefix your test cases with “test”.  In addition, your class does not need to extend from “TestCase” class.
   @Test public void addition() { assertEquals(12, simpleMath.add(7, 5)); } @Test public void subtraction() { assertEquals(9, simpleMath.substract(12, 3)); }
2. @Before and @After
   Use @Before and @After annotations for “setup” and “tearDown” methods respectively. They run before and after every test case.
   @Before public void runBeforeEveryTest() { simpleMath = new SimpleMath(); } @After public void runAfterEveryTest() { simpleMath = null; }
3. @BeforeClass and @AfterClass
   Use @BeforeClass and @AfterClass annotations for class wide “setup” and “tearDown” respectively. Think them as one time setup and tearDown. They run for one time before and after all test cases.
   @BeforeClass public static void runBeforeClass() { // run for one time before all test cases } @AfterClass public static void runAfterClass() { // run for one time after all test cases }
4. Exception Handling
   Use “expected” paramater with @Test annotation for test cases that expect exception. Write the class name of the exception that will be thrown.
   @Test(expected = ArithmeticException.class) public void divisionWithException() { // divide by zero simpleMath.divide(1, 0); }
5. @Ignore
   Put @Ignore annotation for test cases you want to ignore. You can add a string parameter that defines the reason of ignorance if you want.
   @Ignore("Not Ready to Run") @Test public void multiplication() { assertEquals(15, simpleMath.multiply(3, 5)); }
6. Timeout
   Define a timeout period in miliseconds with “timeout” parameter. The test fails when the timeout period exceeds.
   @Test(timeout = 1000) public void infinity() { while (true) ; }
7. New Assertions
   Compare arrays with new assertion methods. Two arrays are equal if they have the same length and each element is equal to the corresponding element in the other array; otherwise, they’re not.

   public static void assertEquals(Object[] expected, Object[] actual);
public static void assertEquals(String message, Object[] expected, Object[] actual);

   @Test public void listEquality() { List<Integer> expected = new ArrayList<Integer>(); expected.add(5); List<Integer> actual = new ArrayList<Integer>(); actual.add(5); assertEquals(expected, actual); }
8. JUnit4Adapter
   Run your Junit 4 tests in Junit 3 test runners with Junit4Adapter.
   public static junit.framework.Test suite() { return new JUnit4TestAdapter(SimpleMathTest.class); }

Happy coding.

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Have you ever wondered how TUX borned? Yes, I have. Yesterday night, I performed a little search on net and here is the result:

Everthing starts with a debate on the linux-kernel mailing list about a suitable logo/mascot for Linux. Many many different ideas including noble beasts such as Sharks or Eagles and inspirations from other operating system logos suggested before Linus Torvalds (the father of Linux) said: “I am rather fond of Penguins”.

After several attempts to draw Penguins in various poses, someone suggested a Penguin holding up the world. Here is the part of famous email from Linus as a response:

So when you think “penguin”, you should be imagining a slighly overweight penguin (*), sitting down after having gorged itself, and having just burped. It’s sitting there with a beatific smile - the world is a good place to be when you have just eaten a few gallons of raw fish and you can feel another “burp” coming.

(*) Not FAT, but you should be able to see that it’s sitting down because it’s really too stuffed to stand up. Think “bean bag” here.

Now, if you have problems associating yourself with something that gets off by eating raw fish, think “chocolate” or something, but you get the idea.

Ok, so we should be thinking of a lovable, cuddly, stuffed penguin sitting down after having gorged itself on herring. Still with me?

OK, but why penguins? Linus explains his love of Penguins in another e-mail as follows:

“Linus likes penguins”. That’s it. There was even a headline on it in some Linux Journal some time ago (I was bitten by a Killer Penguin in Australia - I’m not kidding). Penguins are fun.

As to why use a penguin as a logo? No good reason, really. But a logo doesn’t really ave to _mean_ anything - it’s the association that counts. And I can think of many worse things than have linux being associated with penguins.

Having a penguin as a logo also gives more freedom to people wanting to use linux-related material: instead of being firmly fixed with a specific logo (the triangle, or just “Linux 2.0″ or some other abstract thing), using something like a penguin gives people the chance to make modifications that are still recognizable.

So you can have a real live penguin on a CD cover, for example, and people will get the association. Or you can have a penguin that does something specific (a Penguin writing on wordperfect for the WP Linux CD, whatever - you get the idea).

Compare that to a more abstract logo (like the windows logo - it’s not a bad logo in itself). You can’t really do anything with a logo like that. It just “is”.

Where does the name TUX come from? The first person to call the penguin TUX was James Hughes, who said that it stood for Torvalds UniX in a thread called “Let’s name the penguin” and it is accepted. However, many people observe that TUX is also an abbreviation of tuxedo, the outfit which springs to mind when they see a penguin.

And lastly, you can find lots of funny TUX pics from here. Enjoy it…

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You wanna look at a JVM class while you are coding and you cannot. Here is the solution.

First of all, download your related JDK source code files unless you already have it. In general, source code is included in the JavaSE bundle and located under the root directory of your installation (src.zip mostly).

1. Try to “Open Decleration (F3)” to any JVM class (i.e String class). You will take “Source Not Found” message and below it you will see Attach Source… button. Press it, select the source code file (External File…) and press OK.

2. Go to Project > Properties > Java Build Path > Libraries and expand JRE System Library [your jre version] then, rt.jar. Select Source attachment, click Edit…. Select the source code file (External File…) and press OK.

3. Go to Window > Preferences > Java > Installed JRES and click Edit… for your desired JRE. Expand rt.jar, select Source attachment and click Source Attachment…. Select the source code file (External File…) and press OK.

You can use the above techniques for other libraries that you need to navigate/discover if their source codes are in your hand.

And you’re OK now. Happy coding.

P.S: Menu structure is taken from Eclipse 3.4.0 version.

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A favicon is that stylish little icon that is displayed in your browser next to the website address. If you’re wondering where the name came from then its short for “Favourites Icon”. Its called that because if your visitors add your site to their favourites then it will also shows up on their list making your site stand out that little bit more.

Recently, I created a favicon for my new blog. Before I start working, I searched on the net for a while and found some great online tools for it. Here, I wanna share them with you.

Please don’t hesitate to share yours.
Enjoy them.

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