All posts by Juan Lebrijo

Update your Ubuntu to Java 7

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Download last release from oracle.com, I downloaded jdk-7u1-linux-x64.tar.gz.

Unzip it: tar xvf jdk-7u1-linux-x64.tar.gz

Copy to right place: sudo cp -r jdk1.7.0_01 /usr/lib/jvm

Create java7 alternative: sudo update-alternatives –install /usr/bin/java java /usr/lib/jvm/jdk1.7.0_01/jre/bin/java 1

Choose the alternative: sudo update-alternatives –config java

You can choose between many jvm’s easily.

enjoy!!

Fizz Buzz Java kata

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At XPWeek2011 we learned TDD coding, and the importance of OOP principles to develop applications. I spent great days there, thanks to Carlos Ble and iExpertos.

Continuing with the last kata series. I will show you how I solved FizzBuzz kata, maybe not the best, but I like the solution because the expressive final code:

  • say(FIZZ, WHEN_FIZZ_FACTOR);
  • say(BUZZ, WHEN_BUZZ_FACTOR);
  • elseSayNumber();

Here you have KataFizzBuzz

Here you have the code: fizzbuzz.zip

And here you have the video:

Roman Numerals Java kata

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Continuing with kata series, here we have roman numeral kata. Simple, you have to convert roman to integer and integer to rman.

In order to improve other things I purpossed to follow KISS and SOLID principles. Also creating a Fluent Interface based on static methods:

  • convert(roman).toArabic();
  • convert(arabic).toRoman();

The movie on Youtube:

Kata code here: romannumerals-fluentinterface-solid.zip

Finally, a class diagram illustrating the Open/Close principle which I tried to follow, here we can add more numeric systems only by adding the corresponding Number subclasses (Octal, Hexadecimal,…):

Class Diagram