EL not evaluated in JSP

I've spent almost an hour do discover why Expression Language entries like:

${test}

are not evaluated on JSP pages.

The thing was version in web.xml file.
By default my eclipse generated

<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>

...

Changing to

<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
version="2.4">

...

made it work.

Make sure you have also in your server classpath 2 jar files:

jstl.jar - JSTL implementation classes
standard.jar - Standard Taglib JSTL implementation classes

More reference in this  thread.

InfoQ: It Is Possible to Do Object-Oriented Programming in Java

An interesting presentation about good object-oriented programming practices.

InfoQ: It Is Possible to Do Object-Oriented Programming in Java.

Java Processors

As explained in Wikipedia - A Java processor is the implementation of the Java Virtual Machine (JVM) in hardware.

However, few people know that new Polish construction appeared recently: processor called Warszawa cosntrucred by Polish company http://www.gryftechnologia.com.



During execution of Java program, instructions written in byte code and arguments are sent to instruction decoder. 30% of byte code instructions are realized directly on hardware. The rest is translated to assembly language because of their complicity and additional features of Java Virtual Machine.

An article about the new processor (in Polish) can be found here.

Web Design Techniques

I found recently an interesting speach about good web design techniqes. Putting it mostly for myself for reference.
http://ontwik.com/ui/design-for-developers-making-your-frontend-suck-less/

The presentation for this can be downloaded from Idan Gazit blog.

In context of good color design I found some time ago a color scheme generator here. You can read generated RGB for free.

Global Code Retreat Day 2011

First Code Retreat took place in Java User Group Lodz on 3rd December.
Under vigilant supervision of Piotr Przybylak 12 programmers were improving their skills in context of Test Driven Development.
From 10.00 to 16.00 (roughly) in the office of Mobica company we went through several sessions, 45-minutes each, during which in pairs (different every session) we tried to implement Game of Life. Unfortunatelly noone succeeded to finish the application, but that was not the aim. The goal was to be comfortable with every line of code, to make it ideal given certain assets (such as e.g.: using no setters and getters, having rich domain model, in contrary to anemic domain model)

How does pair-programming look like? What is TDD about? It is well reflected in this conversation.

Every participant of today's event gained something new. I learnt a few Eclipse shortcuts, creating code templates in it, different aproaches to the same problem (objective vs. structural) a few useful libraries (Mockito, Hamcrest) and testing Android application ( thanks Mariusz :))
By chance a few positions worth reading appeared:
Wzorce projektowe. Analiza kodu sposobem na ich poznanie.
Release It!: Design and Deploy Production-Ready Software ( other books of Michael also worth reading)
Continuous Delivery: Reliable Software Releases through Build, Test, and Deployment Automation
Working Effectively with Legacy Code
Holub on Patterns: Learning Design Patterns by Looking at Code

The above list will be updated once I get more positions.

In the meantime we Skype-connected to Code retreat groups in Barcelona and Cracow.
I have a very good impression about this event and would attend similar ones more often.

Learning in practice - priceless, that's something what you can't buy. For everything else there is Master Card ;)

[youtube http://www.youtube.com/watch?v=FdMzngWchDk&w=420&h=315]

[youtube http://www.youtube.com/watch?v=0d6yIquOKQ0&w=420&h=315]


"...it's cats that are complicated"

Photos from event at Picasa Gallery

Nepal 2011

http://intothewild.pl - Nepal, R U ready? I'm comming...

GWT DocLayoutPanel scrolls problem

I was creating a web application using GWT. My base panel is a RootLayoutPanel and I added on it a DockLayoutPanel on which I attached my components.
I came across a problem when changing browser window size to smaller than panel size. The panel size remained unchanged but part of it which was exceeding window size was not visible and there were no scroll bars for browser window.

I struggled with this annoying problem trying to put the DocLayoutPanel inside ScrollPanel, but it did not help at all.
Finally, i found a work around on GWT tutorial at:
http://code.google.com/webtoolkit/doc/latest/DevGuideUiPanels.html#Resize

I've added to my root html page a tag like:



<body>
    ..
    <div id="main" ></div>
    ..
</body>


then in onModuleLoad method instead of adding the panel like:



interface Binder extends UiBinder { }
private static final Binder binder = GWT.create(Binder.class);

public void onModuleLoad() {
    DockLayoutPanel outer = binder.createAndBindUi();
    RootLayoutPanel.get().add(outer);
}



I do it that way:



public void onModuleLoad() {
    DockLayoutPanel outer = binder.createAndBindUi();
    LayoutPanel panel = new LayoutPanel();
    panel.add(outer);
    RootPanel.get("main").add(panel);
    panel.setSize("800px", "800px");
}

NOTE that you must set explicitly the size of the panel to properly display on web page. You should have now scrolls as on any other web page when the panel size exceeds window size.