0

Семинар: Новости в Java платформата.

Posted by JOKe on 7/21/2011 05:12:00 PM

 

Анонса е леко нахално взаимстван от блога на Наков(http://www.nakov.com/blog/2011/07/21/seminar-java-7-java-ee-6-bgjug-27-july-2011/) поради мързел от моя страна да го напиша. Общо взето промените са replace на Найден Гочев с Аз.

 

Имам прекрасна новина за всички Java фенове. След като Java 7 официално излезе, дойде ред и на Българскота общност от Java разработчици да се присъедини към поредицата “Java 7 Launch” събития. Благодарение на много хора :+) ще си направим семинарче и парти по случай Java 7 и новостите от Java света, които идват заедно с нея.

Програма на семинара

    Kакво ново в Java 7?
    Kакво ново в Java EE 6?
    Kакво ново в JavaFX 2.0?
    Kакво ново в JavaME?

Лекциите са част от официалния “Oracle Java 7 Launch Kit”, който е предоставен от Oracle за Българската Java потребителска група (BGJUG) заедно с тениски и други рекламни материали.

Кога и къде?

Семинарът “Новости от Java платформата” ще се проведе на 27 юли (сряда) от 19:00 часа в учебната зала на Академията на Телерик за софтуерни инженери. Адресът е: София, Младост-1, бул. Александър Малинов 33, партер.

Лектор

Лектор ще бъда аз.

Благодарности

Благодарностите за организирането на семинара са за:

    BGJUG – организатор на събитието
    Oracle Corp. които предоставиха Java 7 Launch Kit, тениски и рекламни материали за BGJUG
    Петър Тахчиев, който поръча тениските и launch kit-a.   
    Академия на Телерик – домакин на събитието
    Светлин Наков, който помогна с намирането на домакин ;)



|
0

JavaScript inheritance (object-oriented programming)

Posted by JOKe on 7/05/2011 04:47:00 PM in

 

There are many posts explaining what JavaScript inheritance is how it works, is it bad or good, how it is comparable with Java inheritance with millions of examples using third party apis or function to make inheritance look more like C#/C++/Java Inheritance.

This post is just to show HOW inheritance looks without anything else except browser so next time when you need to find it you can open this post which explains everything you need.

JavaScript uses so called prototype inheritance you don’t need to know more except it is different then a C#/C++/Java way of doing inheritance

Define a class

In JavaScript you can define class like this:

function A(){
    this.aMethod = function (){
        alert("A method");
    }
    this.bMethod = function () {
        alert( "B Method");
    }
}

Yes, yes there are different ways I find this one the most easy one  you can read more about the ways how to create a class in JavaScript here : http://www.phpied.com/3-ways-to-define-a-javascript-class/

Next you have a class how can you use it ?

var a = new A();
a.bMethod(); //will print B method
a.aMethod(); //will print A method

BAM nothing else, easy right?

ok so what if you want to extend this class ?

Prototype Inheritance

First you will create another class:

function B(){
    this.cMethod = function () {
        alert("C method");
    }
}

ok but how can I say that B extends A ? Simple : B.prototype = new A();

Example :

B.prototype = new A();

var b = new B();
b.aMethod(); //will print A method
b.bMethod(); //will print B method
b.cMethod(); //will print C method

Overriding is fine too.

function B(){
    this.bMethod = function() {
        alert("overriding");
    }
    this.cMethod = function () {
        alert("C method");
    }
}

And use it as before ( keep in mind the .prototype = new A is required only ones)

B.prototype = new A();

var b = new B();
b.aMethod(); //will print A method
b.bMethod(); //will print overriding
b.cMethod();// will print C method

Full example:


function A(){
    this.aMethod = function (){
        alert("A method");
    }
    this.bMethod = function () {
        alert( "B Method");
    }
}

function B(){
    this.bMethod = function() {
        alert("overriding");
    }
    this.cMethod = function () {
        alert("C method");
    }
}

B.prototype = new A();

var b = new B();
b.aMethod(); //will print A method
b.bMethod(); //will print overriding
b.cMethod(); //will print C Method

 

Inheritance through Functions

If you don’t like prototypes for some reason you can use a inheritance through functions.

Example:

you just need when you define a class B (the subType) to call this.someFunctionName = supertype and then invoke this.someFunctionName(). Example this.extends = A; this.extends();

Full Example:


function A(){
    this.aMethod = function (){
        alert("A method");
    }
    this.bMethod = function () {
        alert( "B Method");
    }
}

function B(){
    this.extends = A;
    this.extends();
   
    this.bMethod = function() {
        alert("overriding");
    }
    this.cMethod = function () {
        alert("C method");
    }
}

var b = new B();
b.aMethod(); //will print A method
b.bMethod(); //will print overriding
b.cMethod(); //will print C method



UPDATE: Under Internet Explorer if you want to use inheritance through Functions the FUNCTION name that you have to use SHOULD NOT BE "extends" the above example with extends will not work because IE don't like extends :), use some other name like "inheritFrom" for example


|
1

[LINUX] How to find a specific String in file content with specific file name in specific folder

Posted by JOKe on 5/19/2011 12:19:00 PM

 

This is really the dumbest thing ever in linux, there are many many dumb things but this is the dumbest. Ultra trivial task you want to “find a specific string in a file content of specific file type starting from root folder” this is the easiest thing ever, it was not available in Windows XP/98 and because of that I was keeping one JBuilder which can search normally in any java file containing XXX in starting from this folder. But in Windows Vista / 7 this is done EASY just press F3! In Linux on the other hand it is a NIGHTMARE I was having a trivial task which takes… 10 seconds to search for a properties file which contains a default.session.timeout=600 which is a row in this file and this took me more then 30 mins because there are TONS of posts how this is done but none have worked there ware examples using grep, egrep whatever NOTHING is working total CRAP really. So in short I found it somewhere and I want to post it in order to have another POST in google which gives the answers.

So In short:

How to search for a file content in linux in specific file names starting from specific root folder.

find . -name "*.properties" -print | xargs grep default.session.timeout=600

Which will give you all properties files which contains default.session.timeout=600 it doesn’t have to be the match the whole row you can search for just default.session which will give you all files which contains default.session. This command is typed in the folder that you want to start the search from for example /opt/hybris/


|
2

Generate JavaDoc with UML diagrams

Posted by JOKe on 3/11/2011 12:08:00 PM in

In my life many times has happened when I am assigned to a totally new project that I have no idea what it is about, that has to go live in 2 weeks and that I have to fix some issues in this ultra strange code sometimes even code written in different language.

On my question is there any documentation the answer is: Yes but it is very old or no. So in short they want me to start working on a project with no documentation at all.

My second question is is there a javadoc and the anwer is : yeah … kind of … so I am in a project with 30% javadoc with methods in French language for example ( I don’t know even a single word in French) so in short I am loosing 2 weeks to understand what is using what what is the model what is PersonnePhysique  and what is this crazy domain model.

I believe this has happened with everyone of you at least once so what can you do ?

  • You can start digging into the java code like crazy ( like everyone of us have tried many times)
  • You can install intellij idea and use the great reverse engineering way to create UML diagrams for specific classes but intelliJ idea costs money.
  • You can install netbeans 6.5 and do the same but you have to use this out dated version of NetBeans because this doesn’t exist in newer versions, thanks Oracle.
  • You can install Eclipse + MoDisco + MDT + KML to generate xmisomething file then to generate xml file with KML thingy then to use UML2 tools to view this diagram blah.
  • Or you can find some other way… this is the other way which I believe is very nice and useful and you should use it in every project that you can actually this should be the first thing that the architect should put in the project.

So in short the other way is to generate a UML diagrams each time when a javadoc is generated it will generate a UML diagrams for each class and package which contains whatever you want operations,attributes,constructors just names you can click on them and navigate using them it is AWESOME.

How this will look like ? like this:

uml1

And you can click on items for example on Category which will forward you to the Category javadoc which has a diagram as well which looks like this :

UML2

Awesome right ?

How you can do it ? In my example I will use maven so what you have to do :

use of UmlGraph

use of Graphviz

change of maven pom.xml update (for ant integration check the last link in the blog post)

1) install graphviz on the machine that will generate the javadoc .. usually this is a linux machine which runs hudson or whatever so in case of ubuntu you just need apt-get install graphviz4 otherwise you can download the msi/deb/rpg/source from here http://www.graphviz.org/Download..php then just type “dot –-help” in console to check that the dot executable is in your path.

2) update your pom.xml adding UmlGraph just add:

<plugin>
                <artifactId>maven-javadoc-plugin</artifactId>
                <version>2.7</version>
                <configuration>
                    <aggregate>true</aggregate>
                    <show>private</show>
                    <doclet>org.umlgraph.doclet.UmlGraphDoc</doclet>
                    <docletArtifact>
                        <groupId>org.umlgraph</groupId>
                        <artifactId>doclet</artifactId>
                        <version>5.1</version>
                    </docletArtifact>
                    <additionalparam>
                        -inferrel -attributes -types -visibility -inferdep -quiet -hide java.* -collpackages java.util.* -qualify -postfixpackage
                        -nodefontsize 9
                        -nodefontpackagesize 7
                            </additionalparam>
                </configuration>
            </plugin>

3) invoke mvn javadoc:javadoc … and you are done. :+) easy right ? You can see explanation about all umlgraph options here http://www.umlgraph.org/doc/indexw.html like do you don’t want to see the attributes, but you want the operations and etc..

Example with operations will look like this:

 

For ant integration check http://java.dzone.com/articles/reverse-engineer-source-code-u


|

Copyright © 2009 JOKe's Blog All rights reserved. Theme based on the Theme by Laptop Geek with changes by JOKe. | Bloggerized by FalconHive.