Къде?

Събитието ще се проведе на 29.09.2011 г от 19:00 до 21:00 в зала 325, на Факултет по математика и информатика към СУ "Св. Климент Охридски".

Описание

Портлетите представляват видимия и полезен за крайния потребител резултат от внедряването на Service Oriented Architecture (SOA). Те са технология, която дава възможност на бизнес организациите да осигурят повече функционалност, гъвкавост и възможност за персонализация за своите клиенти. С помощта на Web Services for Remote Portlets (WSRP) стандарта на OASIS за отдалечено публикуване на портлети става възможно бизнес услугите лесно да бъдат интегрирани в партньорски портали. Стандартът се ползва с подкрепата на големите доставчици на портални решения като Oracle^®, IBM^® и Microsoft^®.

Внедряването на централизирани уеб портали предлага редица предимства за бизнеса:

• осигуряват входна точка за достъп за всички служители, партньори и клиенти
• предлагат достъп до бизнес функционалността прозрачно и независимо от устройството и местоположението
• порталите са гъвкави – те могат да съществуват под формата на B2E intra-nets, B2B extra-nets или B2C inter-nets
• могат да бъдат комбинирани в портални мрежи, които обхващат цялата бизнес екосистема на организацията
• понеже осигуряват „front end“ за различни уеб услуги, те позволяват лесно интегриране на хетерогенни съществуващи приложения и са отворени към бъдещето (future-proof).

В последните години Java портлетите станаха популярна технология, която позволява лесно споделяне и комбиниране на приложения от различни организации и индивиди в персонализиран уеб портал. Новият портлетно-базиран стил на разработка на уеб приложения дава възможност за създаване на по-разпределени, гъвкави и лесни за повторно използване компоненти, в сравнение с традиционните монолитни решения. Портлетните приложения типично се състоят от множество различни портлети, които могат да бъдат гъвкаво позиционирани върху уеб страницата и комуникират помежду си с използване на споделени параметри (shared parameters), събития (publish/subscribe events), съгласно Portlet Specification 2.0, или чрез JavaScript и AJAX (без презареждане на страницата).

Презентацията демонстрира разработката на портлети с Portlet 2.0 Specification (JSR-286) и портален сървър Liferay (http://www.liferay.com). Liferay е едно от водещите портални решения с отворен код, лидер в Gartner®'s Magic Quadrant for Horizontal Portals.

Включени са демонстрации на JSP, JSF и Spring портлети, Mashups с използване на Google Maps, както и новости при разработката на портлети с JSF 2.0 и JSF 2 --> Portlet 2 Bridge (http://www.portletfaces.org) и IceFaces (http://www.icefaces.org). Ще бъдат разгледани също допълнителни примери за JavaScript портлети и използване на новата JS библиотека Alloy UI базирана върху YUI3 (http://yuilibrary.com/projects/yui3), която замени jQuery при Liferay 6.

Лектор

Траян Илиев е магистър по Информатика от Софийски университет „Св. Климент Охридски“. От 2003 той е управител на IPT - Intellectual Products & Technologies (http://www.iproduct.org). Компанията е специализирана в провеждането на обучения по JAVA^™ SE/EE технологии.

От 2000 година той преподава в Софийски университет, Факултет по математика и информатика, където води курсове: Обектно ориентиран анализ и проектиране с езика UML, Информационни и комуникационни технологии, Системи за подпомагане вземането на решения, Мултимедийни технологии, Изкуствен интелект. Участвал е в редица национални и европейски изследователски проекти.

Сред неговите технически и изследователски интереси са Service Oriented Architecture, business systems and process modeling using UML and BPMN, Java portlets and portal frameworks (Liferay, GateIn, etc.), AJAX and JavaScript libraries, Java EE technologies (EJB 3.1, JSF 2.0, JPA 2.0, EJB^™ 3.1, JSF 2.0, REST-ful web services, WSRP), Java multithreading, multi-agent technologies (http://www.h2j.org).

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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 ;)

П.П. Всеки .net-ър, който желае да премине на така наречената light side of the force е добре дошъл, дори при добро поведение може да получи тениска. Все пак всички знаем, че .net е просто най-разпространения fork на Java ;+) .

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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

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OK don’t get me wrong. I like the new way of JavaFX 2.0 I liked the JavaFX Script but not so match so I like that they get rid of it and that they just plan to make a nice library (alternative to Swing) for creating RIA apps. But please Oracle why this JavaFX still looks like CRAP ?

I’ve posted an old post for font rendering ( http://gochev.blogspot.com/2009/08/ria-technologies-lets-compare-font.html ) not many things has been changed since then.

JavaFX was originally created in 2009 I believe 2 years ago at that time the Swing Font rendering also was looking bad on windows BUT NOW IT LOOKS AWESOME. Swing fonts are rendered as 100% cleartype native fonts you cannot make the difference, the things that make many developers use SWT instead of Swing ware gone, because Swing was looking great. But JavaFX… it was looking like CRAP the UI was having nothing RIA inside it even doesn’t have normal looking fonts.

Today … 2 years later we have JavaFX 2.0 beta… and this beta still looks like CRAP

https://lh6.googleusercontent.com/-r4-Nx7saQQA/TgRH4uC_6aI/AAAAAAAAAoM/_-DFGNwxid8/JavaFX20StillLooksLikeCrap.png

Really ??? Common Guys it is normal there is no real JavaFX application the fonts are UNREADABLE

Oki anyway the other camp Microsoft … Silvercrap … again it was release in 2007 ! The fonts still looks like NIGHTMARE.

https://lh5.googleusercontent.com/-QCgfRFTQRew/TgRJSbyvqmI/AAAAAAAAAoU/4QMDRj-7tco/silverlightCrap.png

Microsoft even successfully broke the IE9 fonts so nothing new. Maybe now when everything in the browser looks like Crap thanks Microsoft maybe now the people will not notice the silverilght crappy fonts.

I am not an adobe fan but I am starting being one because Flash/Flex fonts really looks AWESOME why Adobe can make it and the Microsoft/Oracle cant ? No idea but in any way I understand why Flash/Flex are so popular they are just made for RIA they LOOKs nice and no no they look AMAZING

Example a Flex 4.5 application:

https://lh5.googleusercontent.com/-XPYBGVdSuVk/TgRIoJHEtMI/AAAAAAAAAoQ/Uh9gFDfYZ1E/FlashFontsAreAwesome.png

What can I say ? Ok we have many frameworks for creating RIA and actually only one which is useful.

P.S. if you ask me ActionScript is a lot like Java maybe it actually really looks like the Script for Java (shame I cannot call it JavaScript because the name is taken )

UPDATE:
I just red that the font rendering in WPF 4 has been fixed (maybe because Visual Studio 2010 is written in WPF) so .. in WPF it is fine but in silverlight it is not strange.. Still in WPF it is broken by default and you have to use TextOptions.TextFormattingMode="Display" For more info check out http://blogs.msdn.com/b/text/archive/2009/08/24/wpf-4-0-text-stack-improvements.aspx

Anyway in short normally it looks like this:

https://lh3.googleusercontent.com/-UKqYV16FWeo/TgRcfMjS_5I/AAAAAAAAAoo/_wKYKJoX49U/WPF4Crap.png

When you add this not default attribute it becomes looking nice

https://lh6.googleusercontent.com/-fuE6QKGWXoI/TgRcfDWVZDI/AAAAAAAAAos/JFA5WzOsWDI/WPFNice.png

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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/

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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:

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 :

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

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It is little strange that no one really uses emptyList like he should in Java.
So this is small post showing how to use the emptyList method in the Collections class.

Question: How to create an empty list ?
lets assume that we have a class Book with multiple titles.
So the class in our examples will be:

import java.util.List;

public class Book {

      private List<String> titles;

      public void setTitles(List<String> titles) {

            this.titles = titles;

      }

      public List<String> getTitles() {

            return titles;

      }

}

Lets say that in our snippet we have something like :

  Book myCrazyBook=new Book();

and we want to assign an empty list to the titles in this book. This is a common scenario if you want to set something to be emptyList in specific case instead of null.

So of course your first try will be something like:
Answer 1:

  myCrazyBook.setTitles(new ArrayList()); 

-WARRNING - ArrayList is a raw type. References to generic type ArrayList<E> should be parameterized

Ok changing to:

  myCrazyBook.setTitles(new ArrayList<String>());   

WTF ? the problem in this answer is not small one :
- you are creating empty ArrayList which basiclly is not needed. ( what if you are in a loop 1000+ empty ArrayLists ? )

Answer 2.

   myCrazyBook.setTitles(Collections.EMPTY_LIST);

-WARNING : Type safety: The expression of type List needs unchecked conversion to conform to List<String>, because the EMPTY_LIST is raw type, which was heavily used before Java 1.5.
The definition of this list is :

    /**

     * The empty list (immutable).  This list is serializable.

     *

     * @see #emptyList()

     */

    public static final List EMPTY_LIST = new EmptyList();

So you see it is not ArrayList or LinkedList or MyCrazyCustomListWhichIUseEveryWhereList.

Answer 3:
Eclipse will tell you this answer : Replace with Collections.emptyList();

      myCrazyBook.setTitles(Collections.emptyList());

COMPILE TIME ERROR: why ? because emptyList invoked like that means List of Objects not List of String. The other thing is that you cannot cast to List<String> because you cannot cast List<Object>  to List<String>.

Answer 4:
You know that there is Collections.emptyList() AND YOU KNOW THAT IT RETURNS List<T>
so your answer is:

            Book myCrazyBook=new Book();

            List<String> titles = Collections.emptyList();

            myCrazyBook.setTitles(titles);

           

And this will work WITHOUT any WARNINGS or ERRORS. The type of the List is taken from the type of the variable that you are trying to assign to.
Of course why you need this local variable ? I want to remove it it is not needed and used, but if you remove it you are in Answer 3. So what can you do ?

Answer 5: The right but strange looking answer.

            Book myCrazyBook=new Book();

            myCrazyBook.setTitles(Collections.<String>emptyList());

Yes this is not a joke there is a dot (.) then the generic type before the method name. This compiles, runs, no warnings thats the real way.
It is a little strange that most people dont know this aspect of generics in Java even I didn't know it, I was thinking that you cannot pass a generic type like this but as it looks you can.

So if you have some static method like this one:

public class Main{

      public static <G> List<G> someGreatMethod(){

            List<G> gList= new ArrayList<G>();

            return gList;

      }

}

you can invoke it with Main.<String>someGreatMethod(); for example.

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