JOKe's Blog

Семинар Java Portlets with Liferay and JSF

2011-09-26T12:11:00.001+03:00

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).

Семинар: Новости в Java платформата.

2011-07-21T17:12:00.005+03:00

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 ;+) .

JavaScript inheritance (object-oriented programming)

2011-07-05T16:47:00.005+03:00

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

JavaFX 2.0 nicer way to write RIA but RIA that still looks like CRAP

2011-06-24T11:33:00.004+03:00

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

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

2011-05-19T12:19:00.001+03:00

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/

Generate JavaDoc with UML diagrams

2011-03-11T12:08:00.003+02:00

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

Using of Collections.emptyList() the right way in Java 1.5+

2010-07-27T16:07:00.001+03:00

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.

Spring MVC, Spring Bean Validation Framework and validating confirm password / confirm email fields.

2010-06-29T12:19:00.001+03:00

How to write validation like confirm password, confirm email and etc in Spring MVC.

NOTE: To make bean validation to work its nice to read this tutorial: <a href="http://wheelersoftware.com/articles/spring-bean-validation-framework.html"></a>

Today I was busy making some validations and implementations on very common scenario:
change email and password.
So we have a new password AND a new email also for both of them we have a confirm email/password field. And we want to validate everything nicely and to show to the user the real validation message if there is some error.
So ... I've to use a form which already uses some annotations like @NoBlank and etc I think everyone of you is using annotations framework if you don't use it SHAME ON YOU !:)

Anyway so I've added some fields to existing form bean:

private String newPassword;
private String confirmNewPassword;
private String newEmail;
private String confirmNewEmail;

Basiclly in my case this is very big form and none of this fields is mendatory so the user can leave all of them blank. My first idea was to add at least Length for the password and Email annotations for the email so I do:

@Length(min=6,max=20)
private String newPassword;
private String confirmNewPassword;
@Email
private String newEmail;
private String confirmNewEmail;

Ok but the confirm fields should have the same rules ? Maybe...
The problem that I saw is that length and email by default means NotBlank.
To make email validator to work or length validator they first check is the field blank. In my case I want the blank to be OK.. so I asked god google what to do.
The answer applyIf.
So at the end I get :

@Length(min = 6, max = 20, applyIf = "newPassword is not blank") //cool right ?
private String newPassword;
private String confirmNewPassword;
@Email(applyIf = "newEmail is not blank") //cool right ?
private String newEmail;
private String confirmNewEmail;

Cool right ? yep it is cool. but let me add the validation for confirmNewPassword and confirmNewEmail.

@Length(min = 6, max = 20, applyIf = "newPassword is not blank")
private String newPassword;
@NotBlank(applyIf = "newPassword is not blank")
private String confirmNewPassword;

@Email(applyIf = "newEmail is not blank")
private String newEmail;
@NotBlank(applyIf = "newEmail is not blank")
@Email(applyIf = "newEmail is not blank")
private String confirmNewEmail;

Nice.. so I have validation on new* fields only if they are not blank. Also I have a validation on the confirm fields only if again new* fields are not blank.
Cool... what left ? ahh the most hard part to check is the confirmpassword the same as the newPassword and is the confirmEmail same as the newEmail.

the first idea ofcourse is to write a custom validator.
So I write this :

class NewPassAndEmailValidator implements Validator {
    @Override
    public boolean supports(Class<?> clazz) {
        return PersonalDetailsFormBean.class.equals(clazz);
    }

    @Override
    public void validate(Object obj, Errors errors) {
        PersonalDetailsFormBean personalDetailsFormBean = (PersonalDetailsFormBean) obj;
        if (personalDetailsFormBean.getNewPassword() != null
                && !personalDetailsFormBean.getNewPassword().equals("")) {
            if (!personalDetailsFormBean.getNewPassword().equals(personalDetailsFormBean.getConfirmNewPassword())) {
                errors.rejectValue("confirmNewPassword", "PersonalDetailsFormBean.confirmNewPassword[customvalidator]");
            }
        }
        if (personalDetailsFormBean.getNewEmail() != null && !personalDetailsFormBean.getNewEmail().equals("")) {
            if (!personalDetailsFormBean.getNewEmail().equals(personalDetailsFormBean.getConfirmNewEmail())) {
                errors.rejectValue("confirmNewEmail", "PersonalDetailsFormBean.confirmNewEmail[customvalidator]");
            }
        }
    }

}

and then in the controller submit method.

validator.validate(personalDetailsFormBean, result); //this invokes the annotation based validator.

NewPassAndEmailValidator newPassAndEmailValidator = new NewPassAndEmailValidato();
newPassAndEmailValidator.validate(personalDetailsFormBean, result);

if (result.hasErrors()) {
... return...
}

This .... WORKS FINE. BUT... ah its not cool :( ... I mean even in struts 1 in 2001 we ware having a validation based on expression. AND we have even better way here... Awesome :D

So I've removed this validator... and write only "this":

@Expression(value = "confirmNewPassword = newPassword", applyIf = "newPassword is not blank")

So the final example looks like this:

@Length(min = 6, max = 20, applyIf = "newPassword is not blank")
private String newPassword;
@NotBlank(applyIf = "newPassword is not blank")
@Expression(value = "confirmNewPassword = newPassword", applyIf = "newPassword is not blank")
private String confirmNewPassword;

@Email(applyIf = "newEmail is not blank")
private String newEmail;
@NotBlank(applyIf = "newEmail is not blank")
@Email(applyIf = "newEmail is not blank")
@Expression(value = "confirmNewEmail = newEmail", applyIf = "newEmail is not blank")
private String confirmNewEmail;

:) ok this looks cool :D maybe not so cool than 20+ if statements to checks for null for some of you to but I like this way :))

JavaEE 5 (JSF + JPA + EJB3) using Eclipse

2009-10-26T17:56:00.028+02:00

Today I will show you how to create Enterprise Application using Java EE 5 and GlassFish.
I will use
- Eclipse 3.5 + WTP
- GlassFish v. 2.1
- JSF Mojarra implementation.
- EJB 3.0.
- JPA Toplink essentials implementation.
- MySQL
No NetBeans or JDeveloper magic involved :)
The prerequirement is:
Add datasource in glassfish. Read this how you can make this here: http://gochev.blogspot.com/2009/10/creating-datasource-in-glassfish-v-21.html

1) First you need to add glassfish in your eclipse.
- Go to Servers View
- Right Click, New
- Choose GlassFish v 2.1 if you dont have glassfish click on Download additional adapters link choose glassfish wait and restart eclipse. Than try again.

2) Create the database

CREATE TABLE `lesson`.`USERS` (
  `id` INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
  `username` VARCHAR(45) NOT NULL,
  `password` VARCHAR(45) NOT NULL,
  `name` VARCHAR(45) NOT NULL,
  PRIMARY KEY (`id`)
)
ENGINE = InnoDB;

3) Create EJB project

4) Add persistance.xml file in META-INF folder

<?xml version="1.0" encoding="UTF-8"?>

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0">

    <persistence-unit name="toursUnit">
     <jta-data-source>lessonMySQL</jta-data-source>
        <class>org.joke.model.User</class>
    </persistence-unit>

</persistence>

5) Create Simple Entity org.joke.model.User

package org.joke.model;

import javax.persistence.Basic;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "USERS")
public class User {

 private Long id;
 private String name;
 private String username;
 private String password;

 @Id
 @GeneratedValue(strategy = GenerationType.IDENTITY)
 public Long getId() {
  return id;
 }

 public void setId(Long id) {
  this.id = id;
 }

 @Basic
 public String getName() {
  return name;
 }

 public void setName(String name) {
  this.name = name;
 }

 @Basic
 public String getUsername() {
  return username;
 }

 public void setUsername(String username) {
  this.username = username;
 }

 @Basic
 public String getPassword() {
  return password;
 }

 public void setPassword(String password) {
  this.password = password;
 }

 

}

6) Create HelloService EJB that will use EntityManager

- The local interface is:

package org.joke.service;
import javax.ejb.Local;

import org.joke.model.User;

@Local
public interface HelloService {
 public User login(String username,String password);
}

-The implementation is:

package org.joke.service;

import java.util.List;

import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

import org.joke.model.User;

/**
 * Session Bean implementation class HelloServiceImpl
 */
@Stateless
public class HelloServiceImpl implements HelloService {

 @PersistenceContext(unitName = "toursUnit")
 EntityManager em;

 public HelloServiceImpl() {
 }

 @Override
 public User login(String username, String password) {
  Query query = em
    .createQuery("select u from User u where u.username = :username and u.password = :password");
  query.setParameter("username", username);
  query.setParameter("password", password);
  
  List<User> result = query.getResultList();
  
  if (result != null && result.size() > 0) {
   return result.get(0); //first user
  }
  return null;
 }

}

7) Create Dynamic Web Project

8) Add JSF to this Dynamic Web Project

- Edit web.xml and add FacesServlet

 <servlet>
  <display-name>FacesServlet</display-name>
  <servlet-name>Faces Servlet</servlet-name>
  <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
  <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
  <servlet-name>Faces Servlet</servlet-name>
  <url-pattern>*.jsf</url-pattern>
 </servlet-mapping>

9) I will use a very simple login form (login.jsp) and home.jsp where you will go if login is successfull.

<?xml version="1.0" encoding="UTF-8" ?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:h="http://java.sun.com/jsf/html" version="2.1">
 <jsp:directive.page language="java"
  contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" />
 <jsp:text>
  <![CDATA[ <?xml version="1.0" encoding="UTF-8" ?> ]]>
 </jsp:text>
 <jsp:text>
  <![CDATA[ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ]]>
 </jsp:text>
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
 <title>Hello JSF Page</title>
 </head>
 <body>
 <f:view>
  <h:messages style="color:red;"></h:messages>
  <h:form id="loginForm">
   <table>
    <tr>
     <td align="right"><h:outputText value="Username: " /></td>
     <td><h:inputText id="username"
      value="#{userBean.currentUser.username}" required="true">
      <f:validateLength maximum="10" minimum="3" />
     </h:inputText></td>
     <td><h:message for="username" style="color:red;" /></td>
    </tr>
    <tr>
     <td align="right"><h:outputText value="Password: " /></td>
     <td><h:inputSecret id="password"
      value="#{userBean.currentUser.password}" required="true" /></td>
     <td><h:message for="password" style="color:red;" /></td>
    </tr>
    <tr>
     <td colspan="3"><h:commandButton value="login"
      action="#{userBean.login}" /></td>
    </tr>
   </table>


  </h:form>
 </f:view>
 </body>
 </html>
</jsp:root>

- The home.jsp looks like this:

<?xml version="1.0" encoding="UTF-8" ?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:h="http://java.sun.com/jsf/html" version="2.1">
 <jsp:directive.page language="java"
  contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" />
 <jsp:text>
  <![CDATA[ <?xml version="1.0" encoding="UTF-8" ?> ]]>
 </jsp:text>
 <jsp:text>
  <![CDATA[ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ]]>
 </jsp:text>
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
 <title>Hello JSF Page</title>
 </head>
 <body>
 <f:view>
   Welcome user 
  
 </f:view>
 </body>
 </html>
</jsp:root>

- and faces-config.xml looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<faces-config xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
      http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd"
 version="1.2">
 <navigation-rule>
  <from-view-id>/login.jsp</from-view-id>
  <navigation-case>
   <from-outcome>success</from-outcome>
   <to-view-id>/home.jsp</to-view-id>
  </navigation-case>
 </navigation-rule>
 
 <managed-bean>
  <managed-bean-name>userBean</managed-bean-name>
  <managed-bean-class>mbeans.UserBean</managed-bean-class>
  <managed-bean-scope>session</managed-bean-scope>
 </managed-bean>
</faces-config>

-The UserBean source is:

package mbeans;

import javax.ejb.EJB;
import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;

import org.joke.model.User;
import org.joke.service.HelloService;

public class UserBean {
 private User currentUser = new User();
 @EJB
 private HelloService helloService ;

 public void setCurrentUser(User currentUser) {
  this.currentUser = currentUser;
 }

 public User getCurrentUser() {
  return currentUser;
 }

 public String login() {
  User result = helloService.login(currentUser.getUsername(),
    currentUser.getPassword());
  if (result!=null) {
   currentUser = result;
   return "success";
  }
  FacesContext.getCurrentInstance().addMessage(
    null,
    new FacesMessage("username and password not found"));
  return null;
 }

}

10) You can notice that I use HelloService and User model class in the Dynamic web project. To do this you have to add the service project as referenced by the web project.
- Right click on the web project and choose Properties

-Go to Build path/Projects

-Add the services project

-Now check the UserBean it should not contain any errors.
11) Create Enterprise Applicatin and add Web and EJB module to this application

12) Right click on the Enterprise Application and choose Run on server.

13) go to http://localhost:8080/HelloWeb/login.jsf and test it :)

That's all.
Note that we did not include any third party jar files in this projects. This is because GlassFish include JSF 1.2 Mojarra implementation and Toplink JPA implementation.

*Update : full source code of the example you can download from: http://dl.getdropbox.com/u/887821/HelloJavaEE5.rar

Creating DataSource in GlassFish v. 2.1

2009-10-26T17:06:00.012+02:00

I will show you how to create a DataSource in GlassFish version 2.1 because there were a lot of properties and I had a lot of problems when I've try to register datasource in glassfish for the first time.

1) You have to download JDBC driver for your database. For example I will use MySQL and I will use Connector/J driver that you can download from mysql official web site.

2) Place the JDBC driver in for example D:\glassfishv21\domains\domain1\lib\ext for example my driver is mysql-connector-java-5.0.4.jar

3) Start the domain for example domain1 (asadmin start-domain domain1)

4) go to http://localhost:4848 and login as admin. By default the username is 'admin' and the password is 'adminadmin'

5) go to Resources/JDBC/Connection Pools

-First we will create a connection pool. Click the 'NEW' button

-Than you must type:
- Name: of the connection pool for example MySQL Lessson
- Resource Type: javax.sql.ConnectionPoolDataSource
- Database Vendor: MySQL

-Press 'Next'
-On the Next step scroll down you will see a list of properties. The important for you (you must select this checkboxes) are: 'user','password','url'. If some of this is missing for example there is no 'url' if the vendor is Oracle you can add it using the Add property button.
- user : root
- password : rootpassword
- url : jdbc:mysql://localhost:3306/lesson?autoReconnect=true&characterEncoding=utf8

-When you fill this 3 properties you must press 'Save'
-Than select again your datasource and press 'Ping' to see is everything correct

You are now ready to create your DataSource that will use this connection pool.

6)go to Resources/JDBC/JDBC Resources

- Press 'New'
- Type some jndi name of the resource that you will use latter in your project(s)
- Choose PoolName to be the pool that you have just created.

Now we have DataSource that we can use from any Enterprise/Web Application.
In the next lesson I will create Java EE 5 application using JPA, EJB, JSF using eclipse and this app will use this datasource.

CV

2009-10-26T14:43:00.005+02:00

Who am I?

When you read some blog maybe you are wondering:
Who is this guy?
For that reason I will add my CV to my blog, I think this is enough :). You can download the PDF version from here.

Code Snippet Manager in Java and Swing

2009-09-27T23:40:00.009+03:00

Today I've try to create code snippet manager using Java and Swing. In my previous post I try to done this using WPF and C# (http://gochev.blogspot.com/2009/09/code-snipper-manager-in-c-and-wpf.html) I've just wanted to see how harder is to create the same app using Java and Swing.
First lets make some compare about the WPF and Swing version of the app.
The WPF version consists of 5 files(2 XAML files and 3 cs files with classes)

The WPF version uses XAML for the view (only 30 lines) and 8 lines in file called App.xaml.
The C# class with the logic is 208 lines of code. The Snippet model class is not 62 lines of code using C# properties and etc.

The Java version have 3 classes. One is the main class, the snippet model class 54 lines (most of them created automatically by eclipse like getters setters in C# YOU HAVE TO WRITE THEM MANUALLY) and the Logic + View class is 290 lines of code.

So in conclusion I can say that Java version is 40 lines of code more but this is because of the event handlers which are anonymous classes everywhere in my code.

Anyway the result is :
WPF app looking like this (on left) and Swing app on right:

As you can notice the WPF app looks very worse. Maybe because of the fonts which are not clear typed AND I CAN'T MAKE THEM CLEAR TYPE :) The Swing app have clear type fonts and I've included Substance look and feel because it have nice animations and hover effects.
The result is - Swing app which looks better under Windows and All OSes (WPF is only for Windows).

So if you ask me I will stick to Swing maybe it takes more lines of code for the same view but it looks better and I don't like to write and debug XML.
The Swing version of code snippet manager is available at http://code.google.com/p/snippet-manager/ it has the fallowing features:
- insert snippet from clipboard
- delete selected snippet
- insert separator
- save all snippets to XML file
- load snippets from XML file.

Java2Days conference in Bulgaria, Europe 8-9/10/09

2009-09-14T12:42:00.007+03:00

Java2Days conference is a brand new event in Eastern Europe to present the latest trends in Java development.

Java2Days will be held at the Inter Expo Center on 8-9 October in Sofia, Bulgaria. The conference is hosted by Insight_technologies and the Bulgarian National Academy for Software Development.

The conference is the first of its kind to be held in Eastern Europe, focused to highlight today’s cutting edge trends in building software applications with Java development tools.

Over two days, more than 600 attendees will meet world famous lecturers, engaged all year round in such events as JavaOne, The ServerSide Java Symposium, Jazoon showcasing their latest knowledge in creating more reliable, scalable and secure solutions using Java technologies in more than 20 technical sessions.

The major purpose of the event is to become a place for passionate Java developers to get in touch with the latest technologies, to become a significant part of the global Java community and to learn from the best.

Registration

Prices

VIP Pass – 175 EUR

VIP Java2Days Pass Includes:

Access to all sessions
Eco bag with advertising materials
VIP promoting gifts
Coffee breaks
Front row seating
DVD with all conference materials, video, photos and etc.
Q & A session with the lecturers

Standard Pass – 110 EUR

Standard Java2Days Pass Includes:

Access to all sessions
Eco bag with advertising materials
Coffee breaks
Q & A session with the lecturers

You can add to your pass:

Lunch – 10 EUR per day

The buffet lunch is in a separate hall with plenty of salads, different kinds of meats, vegetarian dishes and desserts.

Special dinner on 8th of October – 20 EUR

A dinner at a Bulgarian tavern with live folklore songs and dances. A place where one can meet with the lecturers and developers from different countries in a unique atmosphere tasting the world-famous traditional Bulgarian cuisine and drinks. We promise it will be a great unforgettable experience

You can read more about registration at http://java2days.com/pricing and http://java2days.com/registration

Agenda

Here are the main shortlisted topics that will be presented at Java2Days conference:

Speaker	Session
John Willis	Java and the Cloud
Mircea Markus	JBoss clustering solutions
Reza Rahman	Java EE 6 Preview
Reza Rahman	EJB 3.1 Preview
Reza Rahman	Spring and EJB 3 Integration
Reza Rahman	Relational Perspectives for Optimizing JPA
Rob Harrop	Modular Web Applications with OSGi
Rob Harrop	Advanced Concurrency Techniques
Heath Kesler	GWT Tips and Tricks for Beginners
Heath Kesler	Advance GWT Concepts
Josh Long	Getting Started with Spring Integration
Josh Long	JSF++
Josh Long	Getting started with jBPM 4 (and Spring)
Andrew Lombardi	Rapid Application Development with Apache Wicket
Talip Ozturk	Clustering your application with Hazelcast
Bruno Bossola	Solid design principles
Vassil Popovski	VMware and Spring Source: Brining Java to the Clouds
George Moykin	Oracle JRockit – Extreme and Predictable Performance with Java
Anatoli Atanasov	Building Efficient Application Grids with Oracle Coherence

We will continue to add more new topics and new key speakers to make the conference more valuable for you. So, visit our site and stay tuned with all news about Java2Days.

If you have any questions, ideas or comments, just contact us at info@java2days.com

For news about the conference program and agenda please check out http://java2days.com/agenda and news section of the event http://java2days.com/news

XMLSerialization with C#

2009-09-13T18:10:00.003+03:00

When I first hear about XML serialization in C# I thought that it is like Java serialization but the result is XML character stream instead of the default serialization in Java/.net.
But the things are not so great.
The XML serialization in C# is good but it is not the best.
In Java the easiest way to make normal serialization is to implement interface Serializable and to be sure that all fields in your custom class are serializable. If you want to Serialize ArrayList of this objects you dont have problems because ArrayList implements Serializable.

But when you use XML serialization you dont care about Serializable interface. In Java you can make XML serialization this way : http://www.javablogging.com/serialization-to-xml/. You can see that it is simple I thought that in C# the situation is the same but it is not.
To read about serialiization in C# there is tones of info but I didn't found answer like this one in this post:
I will notice only some important aspects of this because when I try C# serialization I have missed some points of this article and i loose 30mins of searching what the problem is.

If you need to serialize ArrayList of strings no problem you can make it this way:

// Serialization
XmlSerializer s = new XmlSerializer( typeof( ArrayList) );
TextWriter w = new StreamWriter( @"c:\list.xml" );
s.Serialize( w, myList );
w.Close();

You can notice that you pass the type of ArrayList to XmlSerializer right? That is the difference.
In Java you don't need to specify what you pass it is "founded" automaticly. But in C# you need to pass all classes that you serialize or I dont know maybe most of all? You have two ways to do this:
If you want to serialize ArrayList of Strings it is ok, but if you want to serialize ArrayList of custom objects lets say Snippets you have to specify this.
For example :

private XmlSerializer serializer = new XmlSerializer(typeof(ArrayList),
 new Type[] { typeof(Snippet)});

and if you have a big hierarchy like class A, Class B :A , Class C:A you have to pass all of them. For example:

new XmlSerializer(typeof(ArrayList),
 new Type[] {  typeof(A),typeof(C),typeof(B) });

if you ask me this is dumb. But wait there is another way and it is explicitly telling the serializer to expect the Snippet class when serializing ArrayList of snippets.
For example :

    // This attribute enables the ArrayList to be serialized:
    [System.Xml.Serialization.XmlArray("Snippets")]
    // Explicitly tell the serializer to expect the Snippet class
    // so it can be properly written to XML from the collection:
    [System.Xml.Serialization.XmlArrayItem("snippet",typeof(Snippet))]
    public ArrayList listSnippets;

I don't know did you get the idea, but if you ask me Microsoft make something very easy (as you can see in the java example) harder.
But one think I can say to microsoft is that attributes for XML serializations are nice.
What am I talking about ? lets say that we want to edit the Snippet class or we can edit it.
If you leave the default implementation of Snippet:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;

namespace CodeSnippetManager
{
    public class Snippet
    {
       
        public static int counter = 0;

        public Snippet ()
        {
            counter++;
            Id = counter;
        }

        public int Id { get; set; }

        private String label;
        public String Label {
            get
            {
                return label;
            }
            set
            {
                if(value != null && value.Length > 20)
                {
                    value = value.Substring(0, 20);
                    value.Replace("\r\n", "");
                }
                this.label = value;
            }
        }
        public String Data { get; set;}
        public Snippet(String label,String data)
        {
            this.Label = label;
            this.Data = data;
            counter++;
            Id = counter;
        }

        public override string ToString()
        {
            return Id  + ") "+ label;
        }
    }
}

Btw this class is used in my code snippet manager. So if you keep this and save ArrayList of Snippet objects the result XML looks like this:

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfAnyType xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <anyType xsi:type="Snippet">
    <Id>1</Id>
    <Label>ublic static int cou</Label>
    <Data>ublic static int counter = 0;</Data>
  </anyType>
</ArrayOfAnyType>

But you can use XmlRoot and XMLElement attributes to specify the names of the XML Elements.
If you Snippet class looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;

namespace CodeSnippetManager
{
    [XmlRoot("SnippetRoot"), Serializable]   
    public class Snippet
    {
        [XmlIgnore]
        public static int counter = 0;


        public Snippet ()
        {
            counter++;
            Id = counter;
        }

        [XmlElement("SnippetId")]
        public int Id { get; set; }

        private String label;
        [XmlElement("SnippetLabel")]
        public String Label {
            get
            {
                return label;
            }
            set
            {
                if(value != null && value.Length > 20)
                {
                    value = value.Substring(0, 20);
                    value.Replace("\r\n", "");
                }
                this.label = value;
            }
        }
        [XmlElement("SnippetData")]
        public String Data { get; set;}
        public Snippet(String label,String data)
        {
            this.Label = label;
            this.Data = data;
            counter++;
            Id = counter;
        }

        public override string ToString()
        {
            return Id  + ") "+ label;
        }
        
    }
}

When you save you get this result :

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfAnyType xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <anyType xsi:type="Snippet">
    <SnippetId>1</SnippetId>
    <SnippetLabel>XmlRoot</SnippetLabel>
    <SnippetData>XmlRoot</SnippetData>
  </anyType>
</ArrayOfAnyType>

So as a conclusion I can say that XMLSerialization in C# maybe is harder than Java way but you have easy way to customize the result which is very good.

P.S. I've used Serializable in the Snippet class just for readability.

Code Snippet Manager in C# and WPF

2009-09-12T21:27:00.005+03:00

Hello all, today I will post a simple code snippet manager created using C# and WPF. The idea of the app is to be used when making presentations and you need to paste all kind of code snippets (html, xaml, C#, java ). The similar tool is used by Karen Corby in MIX09 presentation about creating silverlight controls.
This is my first .net application so you will see all kind of C# strangeness like using "Object" instead of "object" and String instead of "string".
Because this was my first application I choose to use WPF not WinForms because WinForms is a lot like Swing and I've wanted to see "how declarative XML for the UI is better" and I can say: "hmm ok there is some big pluses". Anyway I have little experience with Flex's MXML too and if you ask me the MXML is a lot than XAML.
The code snipper manager application lokks like this :
The view is very simple and I can say that XAML is perfect for creating a simple views and there is tones of snippets in internet for all kinds of examples like popup for example.

The application XAML looks like this :

<Window x:Class="CodeSnippetManager.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Snipper Manager" Height="355" Width="177"  Topmost="True" ResizeMode="NoResize" >
    <Grid Height="309">
        <ListBox Margin="0,-8,0,38" Name="listSnippets" HorizontalContentAlignment="Left" 
                 MouseRightButtonDown="listSnippets_MouseRightButtonDown" 
                 SelectionMode="Single" SelectionChanged="listSnippets_SelectionChanged" 
                 MouseDoubleClick="listSnippets_MouseDoubleClick">
            
        </ListBox>
        <Popup Placement="Mouse" Name="popupHint" HorizontalAlignment="Left"
                 VerticalAlignment="Top" IsOpen="False" AllowsTransparency="True">
            <Border BorderBrush="Black" BorderThickness="1">
                <Grid Background="White">
                    <TextBlock  Background="White"
                    x:Name="PopupTxt"
                    TextAlignment="Center"
                    VerticalAlignment="Center">
                        
                    </TextBlock>
                </Grid>
            </Border>
        </Popup>
        <WrapPanel Height="40" Name="wrapPanel1" VerticalAlignment="Bottom" HorizontalAlignment="Center">
            <Button Height="26" Name="menu" Width="65" Margin="5" Click="menu_Click">Menu</Button>
            <Button Height="26" Name="clear" Width="65" Margin="5" Click="new_Click">Clear</Button>
        </WrapPanel>
    </Grid>
</Window>

Maybe you can notice that code is short and very simple, maybe simpler than MXML in Flex and a lot simpler than Swing/SWF and JavaFX. There is no code fragments on the view and etc. But what i did not understand is why all kinds of Name x:Name and other attributes are needed. The XML schemas are strangely organized if you ask me.
Anyway the project is uploaded here http://snippetmanager.codeplex.com/Wiki/View.aspx?title=Home. You can download the source and edit it if you want or you can download the release version and try to use it.
The application have the fallowing features:
- creating and adding code snippets from the clipboard
- saving sets of snippets as XML files for usage in the future
- loading sets of snippets
- delete snippet if it is inserted by mistake
Maybe you will notice strange fonts rendering ( there is no clear type ). This is because WPF 3.5 doesnt support clear type at this moment. But clear type will be supported in the incoming .net 4.0 release. If you ask me the current fonts looks even bad than the Java Swing font rendering before 1.6 update 10 which is funny.
The Expression Blend application is written in WPF too and the fonts looks also this bad but if you use dark theme (black by default) it is harder to notice the bad looking fonts. So if you want change the application color schema to darker. I will add dark theme when I have time.
The reason why I've created this app is because I often need to write code in front of the students when I make presentations and I think that using a tool like this decrease the possibility to make mistakes when writing.
The idea of this app came after I watch the Karen Corby presentation in MIX09 called Building Microsoft Silverlight Controls btw you can watch it here http://videos.visitmix.com/MIX09/T16F . But because I was unable to find this app I've created my own.

Real Ajax for Real Java Developers: GWT & jQUERY

2009-09-02T00:56:00.001+03:00

In this days every Ajax application uses jQuery or Dojo or something like this. If you ask me jQuery is the most often framework because it is small, it helps a lot, it has cool features and it is promoted by Microsoft (we live in strange days). jQuery can be used for many things one of them is effects. We all know how Flash, Silverilght and JavaFX “Rich UI” look and often with CSS and JavaScript it’s very hard to make things that can be done in easy in flash. The jQuery helps a lot with it fade effects slideUp/slideDown and etc. I as a Java Developer I like GWT but often I use JSF too. When I use JSF I’ve always add JQuery because at certain point I’ve always need to type some javascript and with jquery its easier. When I use GWT I’ve wanted to be able to use JQuery the same way like I’ve use it in JSF app or even better. The solution is GWTQuery or GQuery: http://code.google.com/p/gwtquery/ . From the website we can see That Gwt Query is a jQuery-like API written in GWT, which allows GWT to be used in progressive enhancement scenarios where perhaps GWT widgets are too heavyweight.

When I saw this I said: “awesome”. You can read how to get started from here http://code.google.com/p/gwtquery/wiki/GettingStarted I will not explain how to setup and use gwt query because in the wiki you will get up2date information about possible changes but the result is awesome.

Lets assume that we have a table and we want to hide it when the user clicks a button or link but with some transition effect like fade. To do this I use gwt plugin for eclipse from google and created a simple project. My welcome-file GwtJQuery.html looks like this:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<!-- The HTML 4.01 Transitional DOCTYPE declaration-->
<!-- above set at the top of the file will set     -->
<!-- the browser's rendering engine into           -->
<!-- "Quirks Mode". Replacing this declaration     -->
<!-- with a "Standards Mode" doctype is supported, -->
<!-- but may lead to some differences in layout.   -->

<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">

    <!--                                                               -->
    <!-- Consider inlining CSS to reduce the number of requested files -->
    <!--                                                               -->
    <link type="text/css" rel="stylesheet" href="GwtJQuery.css">

    <!--                                           -->
    <!-- Any title is fine                         -->
    <!--                                           -->
    <title>Web Application Starter Project</title>
    
    <!--                                           -->
    <!-- This script loads your compiled module.   -->
    <!-- If you add any GWT meta tags, they must   -->
    <!-- be added before this line.                -->
    <!--                                           -->
    <script type="text/javascript" language="javascript" src="gwtjquery/gwtjquery.nocache.js"></script>
  </head>

  <!--                                           -->
  <!-- The body can have arbitrary html, or      -->
  <!-- you can leave the body empty if you want  -->
  <!-- to create a completely dynamic UI.        -->
  <!--                                           -->
  <body>

    <!-- OPTIONAL: include this if you want history support -->
    <iframe src="javascript:''" id="__gwt_historyFrame" tabIndex='-1' style="position:absolute;width:0;height:0;border:0"></iframe>

    <h1>Web Application Starter Project</h1>

    <table align="center" bgcolor="yellow" id="table">
      <tr>
        <td colspan="2" style="font-weight:bold;">Please enter your name:</td>        
      </tr>
      <tr>
        <td id="nameFieldContainer"></td>
        <td id="sendButtonContainer"></td>
        <td id="hideButtonContainer"></td>
      </tr>
    </table>
  </body>
</html>

The only changes from the base project are the script tag for gwtquery, the id for the table with value “table” and one new column with id hideButtonContainer. The new code is only this:

...
final Button hideButton=new Button("Hide");
...
RootPanel.get("hideButtonContainer").add(hideButton);
...
hideButton.addClickHandler(new ClickHandler() {
			public void onClick(ClickEvent event) {
				hideContainer();
			}
		});
...
	protected void hideContainer() {
		$("table").css("background-color", "grey");
		$("table").click(new Function() {
			@Override
			public boolean f(Event e) {
				$(e).as(Effects).fadeOut();
				return true;
			}
		});
	}
...

We have hideButton, we add it to the RootPanel and we have clickHandler that invokes method called hideContainer. The methods uses GWTQuery which looks like jquery and what we do: we are make instant changing of the background-color to grey and fade effect on the table. You can read the getting started guide of gwt query for more info but the result looks like this:

Real Ajax for Real Java developers: GWT

2009-09-02T00:25:00.001+03:00

Everyone know about GWT right ? This is Java framework for creating real rich ajax applications using the Java language and not using JavaScript. The idea is that your project have two parts : client side and server side. The server side is Java and is compiled to Java using javac and putted in the web server the client side is compiled to JavaScript using GWT Java2JavaScript compiler, the communication between server side and client side is using async call, the result is : real AJAX.

First why I call it real ajax ? The common way to make rich applications this days ( or maybe from 2005 till now) is to use non ajax web framework and use custom ajax controls that uses UpdatePanel or AjaxPanel that makes “partial rendering”.
In typical Non Ajax application (lets use ASP.net or JSF) when we submit the form or make a call using a button server creates the HTML result and send it to the browser. The browser just visualized the HTML and “voala” we have regular page. To create the view in server side is not the best idea but it was used for the last 10 years or more.

Lets create a simple ASP.net page ( I will create ASP.net page not JSF page because it is faster there is no difference in the result and the way how it is created, they are almost the same).

The ASP.net page looks like this:

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <br />
        <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
    </div>
    </form>
</body>
</html>

When we click the button with ID Button1 we invoke some server side logic. So to invoke it we make a submit of our form and executes the action(method) it is the same like we did with Struts in 2002. Our method just changes the text in the TextBox1 LOL we can make it with JavaScript but in 2002 till 2005 no one wants to hear about JavaScript so we have :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        TextBox1.Text = "Voala";
    }
}

when we make a submit of this page the server returns the whole new response and the browser refreshes. I will use firebug to see the response of the call it looks like this:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head><title>

</title></head>
<body>
    <form name="form1" method="post" action="Default.aspx" id="form1">
<div>
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwULLTE0MDM4MzYxMjNkZPJve7rYC/PGVOdFFdRTdiGKYG/K" />
</div>

<div>

	<input type="hidden" name="__EVENTVALIDATION" id="__EVENTVALIDATION" value="/wEWAwLE77ufDwLs0bLrBgKM54rGBv3Oo8jrqGGAkfJCVYhL30amEfxf" />
</div>
    <div>
        <input name="TextBox1" type="text" value="Voala" id="TextBox1" />
        <br />
        <input type="submit" name="Button1" value="Button" id="Button1" />
    </div>
    </form>
</body>
</html>

Wow the result was 804B just for the text Voala, maybe here some Dojo/Mojo etc developer will laugh and say just create a JavaScript function man.

In typical AJAX application using ASP.net and or JSF we have some kind of updatable panel and some JavaScript libraries that are inserted automatically from the framework and that makes the partial rendering. To create an ASP.net AJAX application because it is simpler than JSF RichFaces application. The ASP.net AJAX page looks like this :

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    
    <form id="form1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server">
    </asp:ScriptManager>
    <div>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
            <br />
            <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
        </ContentTemplate>
        </asp:UpdatePanel>
    </div>
    </form>
</body>
</html>

The idea is that when we make a request the response sended from the server is only the content of this UpdatePanel so the response is “HTML” and the JavaScript AJAX library just replaces the old content with the new content (yes it makes a lot of other things like adding listeners to components and etc.) But when we make a call the response looks like this :

189|updatePanel|UpdatePanel1|
            <input name="TextBox1" type="text" value="Voala" id="TextBox1" />
            <br />
            <input type="submit" name="Button1" value="Button" id="Button1" />
        |48|hiddenField|__VIEWSTATE|/wEPDwUINzcxOTk0MDJkZHSPHZdmYurKtHlUqe6IDY0NDG3E|56|hiddenField|__EVENTVALIDATION|/wEWAwKA97K8CgLs0bLrBgKM54rGBocZWWYZCHRaxZUGe6GQYbkXE1Wy|0|asyncPostBackControlIDs|||0|postBackControlIDs|||13|updatePanelIDs||tUpdatePanel1|0|childUpdatePanelIDs|||12|panelsToRefreshIDs||UpdatePanel1|2|asyncPostBackTimeout||90|12|formAction||Default.aspx|

Yes there is some VIEWSTATE “SHIT” that is ASP.net SHIT but you know the idea(you can see this buy yourself with firebug). The result is 584B WOW if you ask me 804B vs 584B not a big deal. The only plus is better use experience because its page doesn't blink. Anyway the RichFaces + JSF example is almost the same the result looks like this

<html xmlns="http://www.w3.org/1999/xhtml"><head></head><body><span id="j_id359:textBox1"
>Voala</span><meta name="Ajax-Update-Ids" content="j_id359:name" /><span id="ajax-view-state"
><input type="hidden" name="javax.faces.ViewState" id="javax.faces.ViewState" value="j_id2" 
/></span><meta id="Ajax-Response" name="Ajax-Response" content="true" /></body></html>

The result is almost the same but there is no BIG viewstate.value. Anyway I’ve hear the term AJAH from one MAX conf so we can say that THIS IS NOT AJAX THIS IS AJAH why ? because the response is HTML so this is Asynchronous JavaScript and HTML, in typical AJAX application like the applications that we want to create we must use JSON for the response and we will want the view to be in the client and we will want to use the server as a server.

How typical ASP.net, PHP, XXX where XXX is everything developers make real AJAX? with JavaScript this will be the way how the things will be done in ASP.net 4.0 too with JavaScript client side controls that will make async calls to ASP.net methods. I can say only OMG. I don't want JavaScript because I dont like Scripting languages and because they dont have the great IDE support that we Java developers want (there is no JavaScript ide like IntelliJ IDEA right ? ). The Java community have an option that other developers dont have : GWT or Real AJax without JavaScript. The result is that we use real AJAX without JavaScript like no one else.

Real AJAX way: lets create a GWT project and add the fallowing content. This is 100% Java code no JavaScript :

public class TestGWTModule implements EntryPoint {
	private Button clickMeButton;
	public void onModuleLoad() {
		RootPanel rootPanel = RootPanel.get();
		
		final TextBox textBox=new TextBox();
		clickMeButton = new Button();

		rootPanel.add(textBox);
		rootPanel.add(clickMeButton);
		
		clickMeButton.setText("Click me!");
		clickMeButton.addClickHandler(new ClickHandler(){
			public void onClick(ClickEvent event) {
				textBox.setText("Voala");
			}
		});
	}
}

And yes we can make async call if we want in the event handler. You can read how we can do that in free GWT documentation provided by google it is easy.In this code we can even use Generics and ArrayLists and almost whatever we will need, yes for example we cant use Threads but do we have Threads in javaScript ? The result is that when we invoke this code we get 0B response why ? Because it is compiled to JavaScript !

Lets make it AJAX so we will need a GWT RPC service you can read how to create one here : http://code.google.com/webtoolkit/tutorials/1.6/RPC.html When we change the clickHandler to make an Ajax call the new handler looks like this :

clickMeButton.addClickHandler(new ClickHandler(){
			public void onClick(ClickEvent event) {
				HelloServiceAsync helloService=GWT.create(HelloService.class);
				((ServiceDefTarget)helloService).setServiceEntryPoint("/hello");
				helloService.sayVoala(new AsyncCallback<String>() {
					@Override
					public void onSuccess(String result) {
						textBox.setText(result);
						
					}
					@Override
					public void onFailure(Throwable caught) {
						// TODO Auto-generated method stub
					}
				});
				
			}
		});

Maybe this looks strange to some of us ( which don't have experience with GWT) but it is not so hard and there is good IDE support which creates most of the code like the service interface, implementation and async object. Anyway the result is that the response is serialized by gwt and looks like this :

//OK[1,["Voala"],0,5]

and it is only 21B ! So yes THIS IS AJAX like it should be. I know that there is some .net projects like Script# that are kind of dead, maybe it is good time to resurrect them? Where is the community ? or Alt.net community ? Guys ? Anyone ? :)

I hope anyone have a clue what the ajax should be and what it is now I really hope to have fastest and better AJAX applications in the feature because this is how the browser must be used not like in 2005.

RIA technologies: lets compare font rendering.

2009-08-20T12:30:00.002+03:00

The idea is to compare the current RIA frameworks like Flex(Flash), Silverlight and JavaFX and see what are the fonts that they produces. We are in 21th century most of the people have laptops and use TFT screens and windows is the most usedOS this days, so most of the people use clear type font rendering. Lets see how each technology uses clear type :

For me the best fonts with clear type enabled are fonts in WinForms and native windows applications. I’ve found very interesting comparison here: http://www.scottlogic.co.uk/blog/wpf/2009/07/silverlight-v3-cleartype-font-rendering-a-comparison/ I will use some of the screenshots from there.

WinForms (ClearType OFF)		You can see that WinForms with ClearType off are still best for CRT screens but not good for TFT screens.
WinForms (ClearType On)		The WinForms + ClearType is the best from microsoft for now.
Silverlight v2.0		Silverlight v2 fonts are so bad I cant see the RIA when I have bad fonts.
Silverlight v3.0		Silverlight v3 have ClearType but it is still far far worst than the WinForms ClearType.
WPF (ClearType off)		WPF with ClearType off is worst than WinForms with ClearType Off it is bad for CRT and bad for TFT displays. It is bad for everything maybe this is the reason why there is no WPF applications.
WPF (ClearType on)		WPF with ClearType on is better than Silverlight for me but it is still bad. In .net 4.0 it will be finally fixed if we can believe to Microsoft.
JavaFX/Swing (Java 1.6u10+)		JavaFX and Swing with Java 1.6 update 10 have very good ClearType support I didn't see the difference between this and WinForms. But to have ClearType in JavaFX you are stick to SwingXXXX controls.
JavaFX 1.2 (node based controls)		JavaFX 1.2 with Node based controls are maybe the worst choice. They are so ugly that I cant believe on my eyes. I was hoping this fonts problem to be fixed in the next JavaFX versions.
Flash 10/Flex 4		Flash 10 and flex 4 looks AMAZING. This is the first “RIA” framework that done the web perfect. I know that Adobe clients are more designers and I like that Adobe is working to make things beautiful.

Summary:

If you ask me and you want nice RIA framework for your good looking 21th century applications use flash. JavaFX is still bad if there is a nice development and designing tools it will be bad again. Silverlight is version 3.0 but it is still far far worst than Flash sometimes my browser freezes because of Silverlight, Expression Blend is WPF application and looks very bad and there is no designers that use Expression Design.

Note : You think Expression Blend is black because Microsoft likes Black GUI ? NO it is black because if was “white” you will see the bad looking fonts. In Expression blend 3 you can change the theme with “white theme” but when you change it you will see “the beauty”.

RichFaces server-side paging with DataTable.

2009-08-19T16:32:00.002+03:00

Most of the component toolkits have build in support for server-side paging this days but in rest of the cases you need to customize a little the data model or data provider or component itself to have data paging. The reason why I write this post is because when I first saw richfaces everythink was perfect except the server-side paging. They have paging but it was client side based on JavaScript witch just doesn't work in many cases and I loose a lot of time to understand all models, which model I must extend and how to do it to create a data model with server side paging. At the current version of RichFaces on the demo page information about how to do server-side paging at least exist http://livedemo.exadel.com/richfaces-demo/richfaces/dataTable.jsf?tab=dataModel&cid=3608154 but like always the JBoss/RedHat/Exadel doesn’t provide us a fast full easy working example and we must loose a lot of time to search for classes in the demo.

The reason why I write this post is to give you simple application that uses server side paging and a little “directions” what you need to customize to have server side paging in all cases. If you have read my previous post about hibernate + spring + jsf + richfaces you will have very easy way to extend this simple demo and to make all Richfaces tables to have server-side paging instead of client-side javascript paging.

So lets start.

First what we want to create ? We want to create a serveri-side paging that looks like this :

When you click on the pager at the bottom it will make ajax call to the server and will fetch the the results for the next page. As you can read in the richFaces demo page you must make custom(extended) data model extending org.ajax4jsf.model.ExtendedDataModel and org.ajax4jsf.model.SerializableDataModel. These two classes work together to provide functions that missing in the standard DataModel.

The most important additional functions are:

access for rows by primary keys instead of index position
implementation of "visitor" pattern over the "range" of rows to support "table scroller" or "paginator" functions
ability to serialize table data, so it can be used on post-back processing without additional database query

In most cases you don’t care about most of this. In our Simple Server-Side richfaces application we will have a simple entity called User. It can be Hibernate/JPA entity or whatever you want for now it will be just a POJO with getters and setters.

package org.joke.demo.extendeddatamodel;

public class User {
 private Integer pk;
 private String username;
 private String password;
 private String fullName;

 public Integer getPk() {
  return pk;
 }

 public void setPk(Integer pk) {
  this.pk = pk;
 }

 public String getUsername() {
  return username;
 }

 public void setUsername(String username) {
  this.username = username;
 }

 public String getPassword() {
  return password;
 }

 public void setPassword(String password) {
  this.password = password;
 }

 public String getFullName() {
  return fullName;
 }

 public void setFullName(String fullName) {
  this.fullName = fullName;
 }

 public String getEmail() {
  return email;
 }

 public void setEmail(String email) {
  this.email = email;
 }

 private String email;

 public User(Integer pk) {
  this.pk = pk;
 }
}

next we will use a simple RandomDataHelper class that will give us random strings and data. This class is downloaded from exadel simple(test) sources.

package org.joke.demo.utils;

public class RandomDataHelper {
 public static int random(int min, int max) {
  assert(min<=max);
  return min+(int)Math.round(Math.random()*(double)(max-min));
 }
 public static Object random(Object values[]) {
  assert(values!=null);
  return values[random(0,values.length-1)];
 }
 private static char randomChar() {
  if (Math.random()>0.5) {
   return (char)((int)'0'+random(0,9));
  } else {
   return (char)((int)'A'+random(0,25));
  }
 }
 public static String randomString(int length) {
  StringBuffer buf = new StringBuffer();
  for (int counter=0;counter<length;counter++) {
   buf.append(randomChar());
  }
  return buf.toString();
 }
}

When we have this we are ready to create our model. The model is copy paste from the exadel model shown in the demo page

package org.joke.demo.extendeddatamodel;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.faces.context.FacesContext;

import org.ajax4jsf.model.DataVisitor;
import org.ajax4jsf.model.Range;
import org.ajax4jsf.model.SequenceRange;
import org.ajax4jsf.model.SerializableDataModel;
/**
 * 
 * @author ias
 * This is example class that intended to demonstrate use of ExtendedDataModel and SerializableDataModel.
 * This implementation intended to be used as a request scope bean. However, it actually provides serialized
 * state, so on a post-back we do not load data from the data provider. Instead we use data that was used 
 * during rendering.
 * This data model must be used together with Data Provider, which is responsible for actual data load 
 * from the database using specific filtering and sorting. Normally Data Provider must be in either session, or conversation
 * scope.
 */
public class AuctionDataModel extends SerializableDataModel {
  
   private AuctionDataProvider dataProvider;
   private Integer currentPk;
   private Map<Integer,User> wrappedData = new HashMap<Integer,User>();
   private List<Integer> wrappedKeys = null;

   /**
     * 
     */
   private static final long serialVersionUID = -1956179896877538628L;

   /**
     * This method never called from framework.
     * (non-Javadoc)
     * @see org.ajax4jsf.model.ExtendedDataModel#getRowKey()
     */
   @Override
   public Object getRowKey() {
       return currentPk;
   }
   /**
     * This method normally called by Visitor before request Data Row.
     */
   @Override
   public void setRowKey(Object key) {
       this.currentPk = (Integer) key;
      
   }
   /**
     * This is main part of Visitor pattern. Method called by framework many times during request processing. 
     */
   @Override
   public void walk(FacesContext context, DataVisitor visitor, Range range, Object argument) throws IOException {
       int firstRow = ((SequenceRange)range).getFirstRow();
       int numberOfRows = ((SequenceRange)range).getRows();
       wrappedKeys = new ArrayList<Integer>();
       for (User item:dataProvider.getItemsByrange(new Integer(firstRow), numberOfRows, null, true)) {
           wrappedKeys.add(item.getPk());
           wrappedData.put(item.getPk(), item);
           visitor.process(context, item.getPk(), argument);
       }
   }
   /**
     * This method must return actual data rows count from the Data Provider. It is used by pagination control
     * to determine total number of data items.
     */
   private Integer rowCount; // better to buffer row count locally
   @Override
   public int getRowCount() {
       if (rowCount==null) {
           rowCount = new Integer(getDataProvider().getRowCount());
           return rowCount.intValue();
       } else {
           return rowCount.intValue();
       }
   }
   /**
     * This is main way to obtain data row. It is intensively used by framework. 
     * We strongly recommend use of local cache in that method. 
     */
   @Override
   public Object getRowData() {
       if (currentPk==null) {
           return null;
       } else {
           User ret = wrappedData.get(currentPk);
           if (ret==null) {
               ret = getDataProvider().getAuctionItemByPk(currentPk);
               wrappedData.put(currentPk, ret);
               return ret;
           } else {
               return ret;
           }
       }
   }

   /**
     * Unused rudiment from old JSF staff.
     */
   @Override
   public int getRowIndex() {
       return 0;
   }

   /**
     * Unused rudiment from old JSF staff.
     */
   @Override
   public Object getWrappedData() {
       throw new UnsupportedOperationException();
   }

   /**
     * Never called by framework.
     */
   @Override
   public boolean isRowAvailable() {
       if (currentPk==null) {
           return false;
       } else {
           return getDataProvider().hasAuctionItemByPk(currentPk);
       }
   }

   /**
     * Unused rudiment from old JSF staff.
     */
   @Override
   public void setRowIndex(int rowIndex) {
    //ignore
   }

   /**
     * Unused rudiment from old JSF staff.
     */
   @Override
   public void setWrappedData(Object data) {
       throw new UnsupportedOperationException();
   }

   /**
     * This method suppose to produce SerializableDataModel that will be serialized into View State and used on a post-back.
     * In current implementation we just mark current model as serialized. In more complicated cases we may need to 
     * transform data to actually serialized form.
     */
   public  SerializableDataModel getSerializableModel(Range range) {
       if (wrappedKeys!=null) {
           return this;
       } else {
           return null;
       }
   }
   /**
     * This is helper method that is called by framework after model update. In must delegate actual database update to 
     * Data Provider.
     */
   @Override
   public void update() {
       getDataProvider().update();
   }

   public AuctionDataProvider getDataProvider() {
       return dataProvider;
   }

   public void setDataProvider(AuctionDataProvider dataProvider) {
       this.dataProvider = dataProvider;
   }

}

Just some notes about it. The important parts for you are two : method getRowIndex() must not be used in JSF 1.2 but MyFaces implementation invokes it some times so in model provided by exadel the method throws exception here we make it to return 0; just because we don't want to have exception with myfaces implementation.

The method public void walk(FacesContext context, DataVisitor visitor, Range range, Object argument) is the miracle this is the method invoked every time when you click the pager. The parameter Range contains the firstRow and countRows that you want to show in the dataTable so you just need to get them. When you have them you need to call your class that provides data. This can be a Service or some kind of data provider. In this simple case we have :

for (User item:dataProvider.getItemsByrange(new Integer(firstRow), numberOfRows, null, true))

so we have class dataProvider and method getItemsByRange. This dataProvider is a field in our dataModel but you can pass it or inject it from spring or from jsf faces-config.

The auction data provider class looks like this :

package org.joke.demo.extendeddatamodel;

       import java.util.ArrayList;
       import java.util.List;

import org.joke.demo.utils.RandomDataHelper;

       public class AuctionDataProvider {

           private String allNames[] = {
                   "Naiden Gochev",
                   "Toshko Poshkov",
                   "Chocho Monchov",
                   "Trallaa Trart",
                   "Peter Taharov",
                   "Djanko bakov",
                   "Hektor Mektor",
                   "Tartal tartalov",
                   "Djadja badja",
                   "Aza Daraz",
                   "Arazd azasd ",
                   "Max Payne",
                   "Max Damage",
                   "Nqkoi Drug",
                   "Treti peti",
                   "Shesti Sedmi",
                   "Talafal Kalafalov",
                   "Iumgur mungurov",
                   "Hrisi hrisi",
                   "Tartalan tartalanov",
                   "Az Taz",
                   "Maz Praz",
                   "Liz languare",
                   "Axa Ratra",
                   "Daraz rasas",
                   "acb asd",
                   "ascv asdv",
                   "ara araaaa",
                   "mon4o gon4o",
                   "petq petrova" };
           private List<User> allItems = null;
           private static final int VOLUME = 200;

           private synchronized void initData() {
               List<User> data = new ArrayList<User>();
               for (int counter = 0; counter < VOLUME; counter++) {
                   User item = new User(new Integer(counter));
                   item.setFullName((String) RandomDataHelper
                           .random(allNames));
                   item.setUsername(RandomDataHelper.randomString(8));
                   item.setPassword(RandomDataHelper.randomString(8));
                   data.add(item);

               }
              allItems = data;
           }

           public List<User> getAllItems() {
               if (allItems != null && allItems.size() > 0) {
                   return allItems;
               } else {
                   initData();
                  return allItems;
               }
           }

           public User getAuctionItemByPk(Integer pk) {
               for (User item : getAllItems()) {
                   if (item.getPk().equals(pk)) {
                       return item;
                   }
               }
               throw new RuntimeException("Auction Item pk=" + pk.toString()
                       + " not found");
           }

           public boolean hasAuctionItemByPk(Integer pk) {
               for (User item : getAllItems()) {
                   if (item.getPk().equals(pk)) {
                       return true;
                   }
               }
               return false;

           }

           public List<User> getItemsByrange(Integer startPk,
                   int numberOfRows, String sortField, boolean ascending) {
            System.out.println("load items from "+startPk + " and count of rows " + numberOfRows);
               List<User> ret = new ArrayList<User>();
               for (int counter = 0; counter < numberOfRows; counter++) {
                   ret.add(getAllItems().get(startPk.intValue() + counter));
               }
               return ret;
           }

           public void update() {
               // nothing need to do
           }

           public int getRowCount() {
               return getAllItems().size();
           }
       }

Thats all this provider contains all the operations that are needed from the model to work. Note the names of the provider and model AuctionDataProvider and AuctionDataModel this was the names in the exadel demo/test application which is not included in exadels demo site. You can find them easy in google, the difference there is that they use AuctionItem not User and the Exadel demo is not so simple and short.

All we need is the view and the faces-config.

The view looks like this :

<?xml version="1.0" encoding="UTF-8" ?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:a4j="http://richfaces.org/a4j"
 xmlns:rich="http://richfaces.org/rich"
 xmlns:h="http://java.sun.com/jsf/html" version="2.1">
 <jsp:directive.page language="java"
  contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" />
 <jsp:text>
  <![CDATA[ <?xml version="1.0" encoding="UTF-8" ?> ]]>
 </jsp:text>
 <jsp:text>
  <![CDATA[ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ]]>
 </jsp:text>

<f:view>
 <h:form>
  <rich:dataTable id="auction" value="#{auctionDataModel}"
   var="item" rows="10">
   <rich:column>
    <f:facet name="header">
     <h:outputText value="full name" />
    </f:facet>
    <h:outputText id="fullName" value="#{item.fullName}" />
   </rich:column>
   <rich:column>
    <f:facet name="header">
     <h:outputText value="username" />
    </f:facet>
    <h:outputText id="username" value="#{item.username}">
    </h:outputText>
   </rich:column>
   <rich:column>
    <f:facet name="header">
     <h:outputText value="password" />
    </f:facet>

    <h:inputText id="password" value="#{item.password}" label="password">
    </h:inputText>

   </rich:column>
   <f:facet name="footer">
    <rich:datascroller for="auction" maxPages="5" />
   </f:facet>
  </rich:dataTable>
 </h:form>
</f:view>
</jsp:root>

And the faces-config.xml looks like this :

<?xml version="1.0" encoding="UTF-8"?>
<faces-config xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
      http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd"
 version="1.2">
 <managed-bean>
  <managed-bean-name>auctionDataModel</managed-bean-name>
  <managed-bean-class>org.joke.demo.extendeddatamodel.AuctionDataModel</managed-bean-class>
  <managed-bean-scope>session</managed-bean-scope>
  <managed-property>
   <property-name>dataProvider</property-name> 
   <value>#{auctionDataProvider}</value>
  </managed-property>
 </managed-bean> 
 <managed-bean>
  <managed-bean-name>auctionDataProvider</managed-bean-name>
  <managed-bean-class>org.joke.demo.extendeddatamodel.AuctionDataProvider</managed-bean-class>
  <managed-bean-scope>session</managed-bean-scope>
 </managed-bean>
</faces-config>

You can notice that I inject the auctionDataProvider in the auctionDataModel here. If you use spring and Spring EL Resolver you can use spring bean container as well.

The full source of this example can be found here: http://dl.getdropbox.com/u/887821/JsfHelloWorld.zip

Hibernate Generic DAO.

2009-08-19T11:53:00.001+03:00

When you use Hibernate and DAO pattern it is a good idea to use a Generic Base Dao. The fallowing code snippet contains GenericDAO that is a base class for all my DAO classes. This GenericDAO uses HibernateDaoSupport from Spring for its implementation if you want you can use JpaDaoSupport or JdbcDaoSupport in your projects.

My Generic DAO interface looks like this :

package org.joke.myproject.dao.base;

import java.io.Serializable;

import java.util.List;

/**

* @author Naiden Gochev

* @param <E>

* @param <PK>

public interface GenericDao<E,PK extends Serializable> {

PK save(E newInstance);

void update(E transientObject);

void saveOrUpdate(E transientObject);

void delete(E persistentObject);

E findById(PK id);

List<E> findAll();

List<E> findAllByProperty(String propertyName,Object value);

}

All method names are very common so I don't think they need some explanation.

The implementation of this GenericDAO :

package org.joke.myproject.dao.base;

import java.io.Serializable;

import java.util.List;

import org.hibernate.criterion.DetachedCriteria;

import org.hibernate.criterion.Restrictions;

import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**

* @author JOKe

* @param <E>

* @param <PK>

public abstract class GenericDaoImpl<E, PK extends Serializable> extends

HibernateDaoSupport implements GenericDao<E, PK> {

@SuppressWarnings("unchecked")

public PK save(E newInstance) {

return (PK) getHibernateTemplate().save(newInstance);

}

@SuppressWarnings("unchecked")

public E findById(PK id) {

return (E) getHibernateTemplate().get(getEntityClass(), id);

}

@SuppressWarnings("unchecked")

public List<E> findAll() {

return getHibernateTemplate().findByCriteria(createDetachedCriteria());

}

@SuppressWarnings("unchecked")

public List<E> findAllByProperty(String propertyName, Object value) {

DetachedCriteria criteria = createDetachedCriteria();

criteria.add(Restrictions.eq(propertyName, value));

return getHibernateTemplate().findByCriteria(criteria);

}

public List<E> findByExample(E object) {

List<E> resultList = getHibernateTemplate().findByExample(object, 0, 1);

return resultList;

}

public List<E> findByExample(E object, int firstResult, int maxResults) {

List<E> resultList = getHibernateTemplate().findByExample(object,

firstResult, maxResults);

return resultList;

}

public void update(E transientObject) {

getHibernateTemplate().update(transientObject);

}

public void saveOrUpdate(E transientObject) {

getHibernateTemplate().saveOrUpdate(transientObject);

}

public void delete(E persistentObject) {

getHibernateTemplate().delete(persistentObject);

}

protected abstract Class<E> getEntityClass();

protected DetachedCriteria createDetachedCriteria() {

return DetachedCriteria.forClass(getEntityClass());

}

The GenericDaoImpl is abstract because the actual DAOs will extend it and will override only one method : protected abstract Class<E> getEntityClass(); This method is used for creating of the DetachedCriteria object in the createDetachedCriteria() method.

Every DAO class that implements GenericDaoImpl will look like this :

package org.joke.myproject.dao;

import java.util.List;

import org.hibernate.criterion.DetachedCriteria;

import org.hibernate.criterion.Restrictions;

import org.joke.myproject.dao.base.GenericDaoImpl;

import org.joke.myproject.entity.Message;

public class MessagesDAO extends GenericDaoImpl<Message, Integer> {

@Override

protected Class<Message> getEntityClass() {

return Message.class;

}

public List<Message> findNotDeletedTextMessages() {

DetachedCriteria criteria = createDetachedCriteria();

criteria.add(Restrictions.eq("deleted", false));

criteria.add(Restrictions.or(Restrictions.eq("custom", false), Restrictions.isNull("custom")));

List<Message> textMessages = getHibernateTemplate().findByCriteria(criteria);

return textMessages;

}

The method here called findNotDeletedTextMessages() is optional it is just another DAO method added in the implementation. If you use Spring you can just add the annotation @Component as class annotation and you have DAO ready for use.

That's all have fun.

Edit : Check out my next article called JSF, Spring, Hibernate – lets make development easy. It will use this GenericDAO to make architecture of an application.